Ch. 10 - 12

Erosion in the Pennsylvanian

Erosion produced great wedge-shaped deposits of red arkosic sandstone during the Pennsylvanian and Permian, some of which are exposed in Colorado as: The "flatirons" near Boulder The rocks at Red Rocks Amphitheatre near Morrison, west of Denver The Garden of the Gods, near Colorado Springs Deposition of Pennsylvanian clastic sediments in eastern Colorado and New Mexico

Evaporites During the Permian

Evaporite deposits (gypsum and salt deposits) accumulated in many areas, as indicated by the green areas in the map above. In fact there are more Permian salt deposits than any other age.

Ferns (true ferns or pteropsids, as opposed to seed ferns) - Phylum Polypodiophyta

Ferns are vascular plants that reproduce by means of spores. They live in moist habitats. Geologic range: Devonian to Recent.

Phylum Cnidaria

Formerly called Phylum Coelenterata (pronounced CELL-enter-otta) Includes the corals, sea fans, jellyfish, and sea anemones. Chief characteristics: Radial symmetry with mouth at the center of a ring of tentacles. Body form may be either a polyp (attached to the bottom, with tentacles on top) or a medusa (free-swimming, umbrella-like, jellyfish shape).

The following marine organisms were extinct by the end of the Permian:

Fusulinid foraminifera Rugose corals Tabulate corals Blastoids Trilobites (which had become extinct somewhat earlier in the Permian) Other groups of organisms were severely reduced in diversity, with some surviving species: Brachiopods Crinoids Bryozoa Ammonoids Organisms which inhabited warm waters shifted their distributions toward the equator. Cool conditions prevented construction of reefs and the formation of limestones. The Permian extinction also affected land dwellers. More than 70% of land animals disappeared or were severely reduced, including: Amphibian families Reptile families Synapsids (which we used to call "mammal-like reptiles") Among the plants, the spore-bearing plants that inhabited tropical coal swamps were replaced by seed-bearing gymnosperms, that could inhabit cooler, drier climatic conditions.

Fusulinid foraminifera (fusulinids)

Fusulinid foraminifera were abundant in the Late Paleozoic (primarily Pennsylvanian and Permian). Their tests were similar in size and shape to a grain of rice. Their internal structure is complex and used to distinguish different species. Important guide fossils in the Pennsylvanian and Permian because they evolved rapidly, were abundant, and widespread geographically.

ORDER OCTOPODA (octopi)

Geologic range: Cretaceous to Recent

ORDER SEPIOIDEA (cuttlefishes)

Geologic range: Jurassic to Recent

ORDER TEUTHOIDEA (squids)

Geologic range: Jurassic to Recent

More on Conodonts

Geologic range: Neoproterozoic (Late Proterozoic) to Late Triassic. Conodonts are extinct, and the organism from which they came is not known with certainty. Significance: Useful in biostratigraphy and marine paleoenvironmental interpretation. Their color is a good indicator of the temperature to which the enclosing rock has been subjected. (This is important in determining whether oil or gas may be present in the rock.) Mode of life: Marine, free-swimming.

CLASS XIPHOSURA (horseshoe crabs)

Geologic range: Silurian to Recent.

Carboniferous Glaciation

Glacial deposits are present in the southern hemisphere, indicating that a glaciation occurred in the Carboniferous and Permian. There are indications of at least four glacial advances at this time in Gondwana.

Tillites and Striations or scratches on the bedrock suggest that this occurred during the Permian:

Glaciation

Ordovician distribution of continents

Global distribution of continents during the Ordovician, showing water depth and presence of evaporite deposits (E), which indicate arid paleoclimates.

Ordovician Diversity

Global diversity TRIPLED. The number of genera increased rapidly, and the number of families increased from about 160 to 530. This increase was particularly dramatic among trilobites, brachiopods, bivalve molluscs, gastropods, and corals.

Ordovician sea levels

Global sea levels were high. Shallow seas cover large areas of some of the continents, particularly North America and Siberia. Sea levels fluctuated during the Ordovician, and dropped sharply at the end of the Ordovician, coinciding with the glaciation.

Cambrian temperature

Global temperatures were probably warm, because tropical waters could not flow far before running into a continent, and being deflected N or S, and spreading warm waters toward the poles Because North America is sitting on the equator (see it running north or south through the center of the map), we expect the waters to be warm.

Chief characteristics of Phylum Porifera

Globular, cylindrical, conical or irregular shape. Basic structure is vase-like with pores and canals. Interior may be hollow or filled with branching canals. Solitary or colonial. Skeletal elements are called spicules, and they may be separate or joined. Composition may be calcareous, siliceous or organic material called spongin.

Alleghanian orogeny in eastern North America and Hercynian orogeny in central Europe Late Carboniferous

Gondwana (the southern continents, Africa, South America, India, Australia, Antarctica) and Laurasia collide. Southern Appalachian mountains form as Laurasia collides with northwestern Africa (part of Gondwana).

Middle Ordovician continent movement

Gondwanaland is moving toward the South Pole, leading to glaciation in Africa at the end of the Ordovician.

There are three basic types of sutures in ammonoid shells:

Goniatite or goniatitic (septae have relatively simple, zig-zag undulations) Ceratite or ceratitic (septae have smooth "hills" alternating with saw-toothed "valleys") Ammonite or ammonitic (septae are complexly branching and tree-like or dendritic)

By the end of the Mississippian what types of rocks were deposited?

Graywackes and shales spread into the depositional basin near the end of the Mississippian, forming a clastic wedge more than 8000 m thick, that thickened and coarsened to the south, where a new mountain range had formed and was eroding.

Just before the Paleozoic began, the Precambrian supercontinent, Rodinia, rifted apart to form six large continents and several smaller continents (microcontinents). The continents were:

Laurentia (North America, including parts of Greenland, Ireland, and Scotland) Baltica (Most of northern Europe and western Russia) Kazakhstania (Between the Caspian Sea and China) Siberia (Russia east of the Ural Mtns and north of Mongolia) China (China, Indochina, and the Malay peninsula) Gondwana (The southern continents, Africa, South America, India, Australia, Antarctica)

Sedimentary deposits of the Mississippi Period are characterized by:

Limestones with fossils of crinoids

CLASS ONYCHOPHORA

Living and ancient velvet worms, including Asheia from the Cambrian Burgess Shale. Onychophorans share many characteristics of segmented annelid worms and arthropods, and are considered to be intermediate in evolution between the two groups. Geologic range: Cambrian to Recent.

Phylum Arthropoda

Insects, spiders, shrimp, crabs, lobsters, barnacles, ostracodes, trilobites, eurypterids Name: means "jointed" (arthro) + "foot" (pod). Chief characteristics: Segmented body with a hard exterior skeleton composed of chitin (organic material). Paired, jointed legs. Highly developed nervous system and sensory organs. Geologic range: Cambrian to Recent. Mode of life: Arthropods inhabit a wide range of environments. Most fossil forms are found in marine or freshwater sediments.

Two major transgressions occurred in North America in the Late Paleozoic:

Kaskaskia (Devonian-Mississippian) Absaroka (Pennsylvanian-Permian)

The two major North American cratonic sequences that formed as a result of transgressions during the late Paleozoic are named:

Kaskaskia and Absaroka

The initial Paleozoic diversification is known as what?

"the Cambrian explosion", referring to the abrupt appearance of many types of animals about 535 million years ago, and the speed with which they radiated or evolved.

CLASS AMPHINEURA OR POLYPLACOPHORA

(Chitons or amphineurans) Name: Polyplacophora means " many plate-bearer" . Chief characteristics: Chitons have 8 overlapping plates covering an ovoid, flattened body. Geologic range: Cambrian to Recent.

CLASS BIVALVIA OR PELECYPODA

(Clams, oysters, scallops, mussels, rudists) Name: Bivalvia means " two" (bi) + " shells" (valvia). Chief characteristics: Skeleton consists of two calcareous valves connected by a hinge. Bilateral symmetry; plane of symmetry passes between the two valves. Geologic range: Early Cambrian to Recent Mode of life: Marine and freshwater. Many species are infaunal burrowers or borers, and others are epifaunal.

The Caledonian orogenic belt

(which extends along the northwestern edge of Europe) is part of the same trend as the Taconic orogenic belt. The Caledonian orogeny reached its climax slightly later, in the Late Silurian to early Devonian. The Caledonian event is recognized in the Canadian Maritime Provinces, northeastern Greenland, northwestern Great Britain, and Norway.

Gondwana during the Devonian

A large continental landmass named Gondwana (composed of South America, Africa, India, Antarctica, and Australia) was present in the southern hemisphere, on or near the South Pole.

During the late Paleozoic, the South Pole was situated over this present-day continent, which contributed to glaciation in Gondwana:

Africa

Pennsylvanian

Late Carboniferous

Large plants (including spore-bearing trees and seed ferns) colonized the land during what?

Late Paleozoic.

Dicynodon

Late Permian (250-230 m.y.), plant-eating reptile. From Cape Province, South Africa.

Latimeria a modern coelacanth

Latimeria, a modern coelacanth about 2 m long, living near Madagascar. Note the similarity of the tail to that of Eusthenopteron fossils, above. The tail is very different from that of the ray-finned fishes.

Laurentia and Baltica collided to form what during the Devonian?

Laurasia in the Caledonian orogeny affecting northeastern Canada, Greenland, and Europe).

Acadian orogeny and Caledonian orogeny Middle Silurian to middle Devonian.

Laurentia (North America) and Baltica (Europe) collide to form Laurasia, and a volcanic island arc (Avalon terrane or Carolina terrane) collides with eastern North America.

The Orogeny that occurred in the western U.S during the Late Paleozoic was:

Antler

Phylum Archaeocyatha Name

Archaeocyatha means "ancient cup"

Late Mississippian Climate

Arid climatic conditions and restricted circulation resulted in the deposition of thick units of gypsum and salt. Petroleum migrated into the permeable reef deposits, forming rich oil fields.

Kaskaskia sea during the Mississippian

As the amount of muddy sediment from the eroding highlands decreased, carbonate deposition became widespread in the warm, shallow Kaskaskia sea.

Geologic range of Phylum Archaeocyatha

Cambrian only. Extinct.

Geologic range for Phylum Porifera

Cambrian to Recent.

Geologic range of Foraminifera

Cambrian to Recent.

Depositional setting of the Middle Ordovician

Carbonate sedimentation ended. The carbonate platform in eastern North America collapsed or was downwarped. This was caused by the partial closure of the Iapetus Ocean along a subduction zone.

The Mississippian and Pennsylvanian periods are sometimes referred to as what?

Carboniferous

There are more plant fossils in __________ strata than in any other geologic interval. Plants gave the Carboniferous its name, because of the vast coal deposits which formed from plant remains in lowland swamps (coal is dominated by the element carbon). Coal represents an enormous biomass of plants because it takes several cubic meters of wood to make one cubic meter of coal.

Carboniferous

After the Devonian Acadian Orogeny in the Appalachian region, this was deposited:

Catskill clastic wedge

CLASS CRINOIDEA (crinoids or "sea lilies")

Crinoids are animals which resemble flowers - they consist of a calyx with arms, atop a stem of calcite disks called columnals. The crinoid is attached to the seafloor by root-like holdfasts. Some living crinoids are swimmers, and not attached. Over 1000 genera are known. Geologic range: Middle Cambrian to Recent. Especially abundant during the Mississippian.

Late Paleozoic

Devonian, Mississippian, Pennsylvanian, and Permian

The three most catastrophic extinctions in the Paleozoic Era were at the following times:

End of the Ordovician Period (443 m.y. ago) End of the Devonian Period (359 m.y. ago) End of the Permian Period (251 m.y. ago) Of these, the Permian extinction was the most severe. In fact, the extinction event at the end of the Permian Period is considered to be the most catastrophic mass extinction in the history of life.

The repeated interbedding of non-marine and marine sedimentary deposits indicates either:

Episodic regional subsidence and uplift OR Eustatic (worldwide) sea level changes related to the Carboniferous-Permian glaciation in Gondwana.

Caledonian Mountains erosion

Erosion of these mountains resulted in the deposition of the Catskill Red beds in the Appalachian area, and the Old Red Sandstone in Europe.

Phylum Porifera - The Sponges

Porifera means "pore-bearing". Exterior covered by tiny pores.

Geologic range Radiolaria

Precambrian or Cambrian to Recent. Rare in Lower Paleozoic rocks. More abundant in Mesozoic and Cenozoic.

CLASS INARTICULATA - The Inarticulate Brachiopods

Primitive brachiopods with phosphatic or chitinous valves; no hinge. Spoon-shaped valves held together with muscles and soft parts. Lingula is a well known inarticulate brachiopod. Geologic range: Lower Cambrian to Recent

CLASS ACANTHODII (the acanthodians or spiny fishes)

Significance: These were the first fishes to have jaws. Name: "Acanthos" means "spiny". Chief characteristics: Primitive spiny fishes with jaws. Geologic range: Late Silurian to Permian. Most numerous during the Devonian. Extinct. Mode of life: Swimmers. Nonmarine.

Silurian sea levels

Silurian sea levels were high worldwide. In North America (Laurentia), much of the craton was flooded, indicating melting of the Late Ordovician glaciers. This was the second major transgression of the Paleozoic, which deposited the Tippecanoe Sequence.

The early Paleozoic climate was affected by several factors:

The Earth spun faster and had shorter days. Tidal effects were stronger because the Moon was closer to Earth. No vascular plants were present on the land.

Where was Gondwana during the Permian?

The Gondwana part of Pangea continued to sit atop the South Pole, and glaciation continued into the Permian.

Iapetus Ocean during the Silurian

The Iapetus Ocean is beginning to close as Laurentia and Baltica converge.

This unconformity separates the Mississippian from the Pennsylvanian.

The Kaskaskia sea retreated from the craton at the end of the Mississippian. This event is marked by one of the most widespread unconformities in the world.

Eusthenopteron

The Late Devonian crossopterygian lungfish, Eusthenopteron (365 m.y., Escuminac Formation, Quebec, Canada) had sturdy fins. It is structurally similar to amphibians and is considered to be transitional to the amphibians.

Antler Mtns

The erosion of the Antler Mountains provided detrital sediment that was transported into adjacent basins. Thick sequences of Pennsylvanian and Permian shelf sediments accumulated in the area now occupied by the Wasatch and Oquirrh Mountains in Utah.

Phosphoria Formation

The formation is named for the layers of dark phosphatic sediments and phosphorites. Phosphorite is a dark gray variety of calcium phosphate that may have been produced by the upwelling of phosphorus-rich sea water from the deeper parts of the basin. Phosphate is mined for fertilizers and other products.

CLASS HEXAPODA (insects - six legs)

The insects are among the most diverse living group on Earth, although they are rarely found as fossils. Body is divided into three parts, head, thorax, and abdomen. Thorax has six legs. Wings may be present or absent. The earliest insects were wingless. Winged insects appeared by the Pennsylvanian. Geologic range: Middle Devonian to Recent.

Lycopods or Lycopsids (club mosses, scale trees) - Phylum Lycopodophyta or Lycopsida

The lycopods are spore-bearing plants, and were confined to swamps because spores require moisture to germinate. Some of them also produced seeds. Some grew to about 30 m tall and were 1 m across at the base. Few exist after the Permian. Geologic range: Silurian to Recent.

Mountains in North America during the Silurian

The mountains in eastern North America are smaller than they were during the Ordovician, due to erosion.

Order Dipnoi or dipnoans (meaning "double breather") -

This group did not lead to tetrapods, but includes interesting freshwater lungfish living today in Australia, Africa and South America. They can breathe with lungs during the dry season, and can burrow into the mud during droughts.

CLASS CYSTOIDEA (cystoids)

This primitive group had a calyx attached to the seafloor by a stem (like crinoids and blastoids). Distinctive patterns of pores on the plates of the calyx. Geologic range: Cambrian to Late Devonian. Most common in Ordovician and Silurian.

Anatomical changes associated with the shift from water to land:

Three-chambered heart developed and functioned to pump blood more efficiently to the lungs Limb and girdle bones altered to support the body above the ground Spinal column changed to become sturdy but flexible Bones of the ear changed to function better in air than in water (modification of hyomandibular bone that propped fish braincase and upper jaw together, into an ear ossicle called the stapes) Fish spiracle (vestigial gill slit) became amphibian eustachian tube and middle ear Eardrum (tympanic membrane) formed across a notch in the skull Amphibians are interpreted to be descended from crossopterygian fishes because of: Arrangement of bones in amphibian limbs compared with the fins of crossopterygian fish Comparison of limb bones of an amphibian with the fin of a crossopterygian fish Comparison of limb bones of an amphibian (left) with the fin of a crossopterygian fish (right). The major limb bones are coded r, u and h. r = radius u = ulna h = humurus Pattern of bones of the skull Comparison of crossopterygian fish and Ichthyostega Comparison of skulls and lower jaws of a crossopterygian fish (left) and the Devonian amphibian, Ichthyostega. Structure of the teeth - highly infolded like a maze (or labyrinth), and called labyrinthodont teeth. Bones of the spinal column in early forms.

Chief characteristics of Foraminifera

Unicellular. Related to the amoeba, with pseudopods. Foraminifera build tiny shells (called tests) which grow by adding chambers singly, in rows, in coils, or spirals. Some species (called agglutinated foraminifera) construct tests of tiny particles of sediement. This is the earliest type of foram test. Other forams construct tests of calcium carbonate.

Radiolaria Chief characteristics:

Unicellular. Related to the amoeba, with pseudopods. Ornate lattice-like skeleton composed of opaline silica. Often spherical or radially symmetrical with spines.

CLASS EURYPTERIDA (eurypterids)

The eurypterids are extinct scorpion-like or lobster-like arthropods which were for a time the dominant predators in the Paleozoic. Some were nearly 10 ft long. They have a semicircular head with compound eyes, and a segmented rear section ending in a long projection called a telson. Two swimming legs are prominent near the head. Also have pincers called chelicerae. Geologic range: Ordovician to Permian. Most are found in the Silurian and Devonian. Mode of life: Inhabited brackish estuaries.

Evolution of Jaws

The evolution of the jaw expanded the adaptive range of vertebrates. Used for biting and grasping. Led to more varied and active ways of life, and to new sources of food. Origin of jaws - two hypotheses: Modification of a front pair of bone or cartilage gill supports. More recent hypothesis: Modification of the velum, a structure used in respiration and feeding in lamprey larvae. Both hypotheses are based on anatomy and embryology of living fishes. The first fish with jaws appeared in nonmarine rocks in the Late Silurian.

What was the worst mass extinction in the history of life?

The extinction event at the end of the Permian Period

Seymouria

a land-dwelling amphibian from the Lower Permian of Texas, 260 m.y. ago, was less than 3 feet long. Note stout limbs, short body and tail. A primitive amphibian similar to Seymouria was probably ancestral to the reptiles

Eryops

a typical Permian amphibian, with short, powerful limbs, which suggest that it was primarily a land dweller.

What occurred when the Iapetus Ocean narrowed?

a volcanic island arc approached and collided with the North American craton, causing folding, faulting, metamorphism, and mountain building.

The sedimentary deposits of the Mississippian Period contain what?

abundant limestone with fossils of crinoids, blastoids, bryozoans, and fusulinid foraminifera.

Pangea means what?

all land

Mississippian Limestones

among the most extensive bodies of limestone in the world. In places, they are more than 700 m thick.

It took tens of millions of generations for crossopterygian fishes to evolve into animals that could live on land. The early tetrapods continued to return to the water to lay their eggs. These first land dwelling vertebrates were:

amphibians

Anapsida (no holes)

amphibians, the earliest known reptile (Hylonomus), and turtles

Hallucigenia

an onycophoran, which was originally interpreted to walk on the spines as legs, but was later reinterpreted to walk on the "tentacles", after claws were discovered on some of them.

Paleogeography

ancient geography." The ancient geographic arrangement of the continents.

Chordates

animals that have a notochord or dorsal stiffening rod associated with a nerve chord, at some stage in their development

Cambrian Glaciers

because the glaciers are melting (or have melted), sea levels are rising, and shallow epicontinental seas flood the continents.

These marine animals have two enclosing symmetrical valves. Their shells dominate many Ordovician limestone formations:

brachiopods

Ichthyostega The skeleton of Ichthyostega, the first amphibian.

chthyostega retained many features of its fish ancestors, such as: Scales Similar skull structure, including arrangement of nostrils Loosely connected fish-like spinal column It also had a number of unique traits such as: Five-toed limbs Pelvic and pectoral girdles, allowing it to walk on land Amphibians inhabited the Carboniferous coal swamps, and were abundant and varied. They had several different modes of life, including some with an aquatic lifestyle (as suggested by features such as a flattened body and skull, reduced limbs, and a slender snake-like body), and some that were clearly land dwellers (with stout limbs, short body and tail).

In eastern North America, the initial deposits of the transgressing Kaskaskia sea were what?

clean quartz sands, such as those of the Devonian Oriskany Sandstone, which is used for glass making because of its purity.

As the Tippecanoe Sea flooded North America, what occurred?

deposition began with nearshore sands. These include the famous St. Peter Sandstone, an unusually pure, well-sorted, well-rounded quartz sandstone. The Silurian Tuscarora Sandstone was deposited in the central Appalachian region.

Vail curves

derived from seismic stratigraphic profiles, which permit tracing of unconformities across the craton and into thick continental margin sedimentary rocks.

Diapsida (two holes)

dinosaurs, flying reptiles, birds, and all groups of living reptiles except turtles

Carboniferous-Permian Diversity

diversity once again increased. Diversity of marine animals remained fairly constant throughout the Carboniferous and Permian. The Late Permian is marked by a catastrophic extinction event which resulted in the total disappearance of many animal groups.

The seed-bearing plants became dominant over the spore-bearing in the Late Paleozoic, perhaps because of:

drier climatic conditions

Infaunal, burrowing animals evolved rapidly when?

during the Cambrian, as indicated by trace fossils and bioturbation of sediments

The supercontinent Pangea (from the Greek, meaning "all land") was gradually assembled as the continents collided when?

during the Late Paleozoic.

Vertebrates including fishes, amphibians, reptiles, and synapsids (so-called mammal-like reptiles) evolved when?

during the Paleozoic

What WAS the conodont animal?

everal fossils of conodont animals have been reported, but most were discredited and reinterpreted as an organism which had actually eaten the conodont animal, because the conodont elements were only in the stomach or digestive tract. A fossil discovered in 1995 in the Ordovician Soom Shale of South Africa contains soft bodied remains of an animal with an elongated eel-like body. The animal had an eye, and had V-shaped musculature along the sides of the body, as in the amphioxus or lancelet. The organism has a longitudinal band which may mark the position of the notochord.

The name "Mississippian" is derived from

exposures of rock along the Mississippi River.

Williston Basin area (South Dakota, Montana, and adjacent Canada),

extensive reefs formed. Restricted circulation within the reef-encircled basin led to the deposition of thick evaporite deposits. The reefs of the Williston Basin provided permeable structures into which petroleum migrated, forming rich oil fields.

During regressions, the former seafloor was exposed to erosion, creating what?

extensive unconformities that mark the boundaries between the transgressive-regressive sequences.

Euryapsida (upper hole only)

extinct marine reptiles

Several of the Paleozoic periods ended with what?

extinction events of varying severity.

As the Late Paleozoic began, the continents were what?

fairly fragmented and separate, particularly in the Northern Hemisphere.

One group of organisms developed a vascular system to transport water and nutrients, and the ability to stand against the pull of gravity. These adaptations helped them live on land. What type of organisms were they?

first land plants

Fossil remains of animals appear in this order (from oldest to youngest) in the geologic record:

fish, amphibians, reptiles, mammals

The Iapetus Ocean (or Proto-Atlantic Ocean)

formed as Laurentia drifted away from South America.

The Paleozoic was a time with abundant what?

fossils of multicellular organisms with shells. As a result, the fossil record improves dramatically at the beginning of the Paleozoic Era.

Diadectes

from the Early Permian (280-250 m.y.) was a land-dwelling plant eater. The skeletal anatomy is reptilian, but the skull resembles that of Seymouria, an amphibian.

Corals

have a hard calcareous skeleton, and may be solitary or colonial. Colonies are composed of many polyps living together.

The Taconic Orogenic Belt

lies between Laurentia (North America) and Baltica (Europe and western Russia) in the Ordovician.

The fossils of shell-bearing invertebrates that inhabited shallow seas are common where?

in Paleozoic rocks

In the western part of North America, the Antler orogeny began when?

in the Devonian with the subduction of oceanic lithosphere beneath the western margin of the continent.

Gradual flooding of the North American craton occurred when?

in the Late Paleozoic, reaching its maximum extent during the Mississippian Period. This new inland sea was called the Kaskaskia sea.

The Alleghanian orogeny began

in the Mississippian and continued throughout the Pennsylvanian and Permian periods.

Fold and thrust fault

in the Pennsylvanian Crab Orchard Mountain Group, formed during the Alleghenian Orogeny. Note the overturned fold and southeast-dipping thrust fault.

What were the conodont elements used for in the conodont animal?

internal laminated structures within the conodont elements indicate that new lamellae were added on the outer surface of many elements, suggesting that they were an internal skeletal appatatus, covered with tissue, rather than being used as teeth. The function of the apparatus is not known. Some conodonts show evidence of having been broken and subsequently repaired. They may have been supports for a food-gathering apparatus. Present evidence strongly favors chordate status for the conodont-bearing animal.

How is the theca is divided

internally by vertical partitions called septae, arranged in a radial pattern

The larger continents (such as North America) grew by the addition of what?

island arcs and microcontinents around their edges

The evolution of this feature in the Silurian enormously expanded the adaptive range of vertebrates, leading to more varied life styles and new sources of food:

jaw

The first vertebrates were what?

jawless fishes, which are found in rocks as old as Cambrian in China.

The Paradox basin

lay to the southwest of the Uncompahgre mountains. Clastic sediments from the mountains were deposited along the northeastern side of the basin. The Paradox basin was flooded by the Absaroka sea in the Early Pennsylvanian, and shales were deposited over Mississippian limestone. Then the basin became restricted and thick beds of evaporites (salt, gypsum and anhydrite) were deposited. Reef-like algal mounds, associated with fossiliferous and oolitic limestones, developed along the western rim of the basin. The reefs serve as petroleum reservoirs. Near the end of the Pennsylvanian, the basin filled with arkosic sediments eroded from the Uncompahgre highlands.

The Acadian and Alleghanian orogenies were the result of the closure of what?

of the Iapetus Ocean and continental collisions which resulted in the formation of the supercontinent Pangea.

Marrella

one of the most common arthropods in the Burgess Shale. Also called "lace crabs."

Pikaia

one of the oldest chordates a fish-like lower chordate. Modern representatives are called lancelets, such as the genus Amphioxus.

The plants progressed from seedless, spore-bearing plants to what?

plants with seeds but no flowers (the gymnosperms). (Flowering plants did not appear until near the end of the Mesozoic Era.)

Devonian Diversity

saw continued diversification, but ended with another fairly large extinction event, which extended over about 20 million years. At this time, roughly 70% of the marine invertebrates disappeared. Because of the long duration, the extinction is unlikely to have been caused by a sudden, catastrophic event.

As the sea continued to transgress, what occurred?

shales, and then limestones with reef-forming coral were deposited over the sands. In areas where water circulation was more restricted, evaporites were deposited.

Middle Silurian

shallow seas appear to have covered more of the continents than at any other time. The epicontinental seas withdrew (regressed) toward the end of the Silurian.

Paleozoic invertebrate phyla

sponges, corals, bryozoans, brachiopods, molluscs, arthropods, and echinoderms

The therapsids were:

tetrapods with mammal-like traits

The significance of the Burgess Shale

that it records soft-bodied organisms, and the soft parts of organisms with shells. The finely detailed preservation reveals the extraordinary diversity and evolutionary complexity that existed near the beginning of the Paleozoic.

Deep seismic reflection profiling studies indicate what?

that the crystalline rocks of the Blue Ridge and Piedmont regions were thrust-faulted onto the craton by the continental collision, sliding at least 260 km to the west. The Blue Ridge and Piedmont metamorphic and igneous rocks form a sheet ranging from 6 to 15 km thick, overlying relatively flat-lying lower Paleozoic sedimentary rocks. This type of tectonic deformation is called "thin-skinned tectonics."

There is an extensive sedimentary record for what period?

the Devonian Period

The first primitive land plants appeared near the end of what?

the Ordovician

Almost all of the common invertebrate phyla in existence today had appeared by what?

the Ordovician.

Sea levels were high in North America during the early Ordovician, and the craton was flooded by this

the Sauk epicontinental sea

The oceanic area east of Pangea, and between Africa and Europe was called what?

the Tethys Sea.

The transition from water-dwelling vertebrates to land-dwelling vertebrates depended on the evolution of what?

the amniotic egg.

Note that the unconformities cover a greater time range near...

the center of the craton. Unconformities near the edge of the craton span less time, if they are present at all. This is because the edges of the craton are most likely to remain flooded. The center of the craton is flooded only during times of major sea level high stands or transgressions.

Halysites

the chain coral because its thecae are attached to one another side-by-side in wavy lines resembling a chain.

Global paleogeography during the Late Neoproterozoic, about 750 mya

the continents are joined, forming the supercontinent Rodinia. Rodinia had begun to rift apart. The surrounding ocean is Mirovia.

Cambrian Continent movement

the continents have moved off the South Pole, and some are sitting on the equator. (We don't expect glaciations in the Cambrian.) Note that some of the continents are separating. Laurentia and Baltica have moved away from South America. Laurentia (North America) is nearly covered by shallow epicontinental seas.

The Alleghanian orogeny produced what?

the folds in the Appalachian Valley and Ridge province, and large thrust faults in the southern Appalachians. Many of these folds are asymmetrically overturned to the northwest, and the surfaces of the thrust faults are inclined southeastward.

The principal groups of Paleozoic unicellular animals with a significant fossils record are what?

the foraminifera and the radiolaria, which belong to Phylum Sarcodina These organisms are unicellular eukaryotic organisms, and belong to Kingdom Protista.

During regressions, such as the one between the Mississippian and Pennsylvanian, what occurs?

the former seafloor was exposed to erosion, creating one of the most widespread regional unconformities in the world.

An advanced lineage of fishes with primitive lungs and stout fins gave rise to what?

the four-legged animals or tetrapods.

Paleomagnetic evidence provides information on:

the latitude at which the rocks formed. The orientation of the continent can be determined from the direction to the paleomagnetic pole, as recorded by bits of iron in the rock.

Vertebrates

the notochord is surrounded by and usually replaced by a vertebral column during embryonic development. It is thought that vertebrates evolved from organisms similar to Pikaia.

During the Silurian, evaporation led to what?

the precipitation of immense quantities of rock salt and gypsum within the basin, indicating an arid paleoclimate. Evaporite minerals total 750 m in thickness in the Salina Group within the Michigan Basin.

The Burgess Shale fauna and Chengjiang fauna are significant because they contain:

the remains of animals that lacked hard parts

Neoproterozoic glaciation

the sea transgressed onto the craton. Shoreline (beach) deposition produced a vast apron of clean quartz sand. Carbonate deposition occurred farther from land.

The Kaibab Limestone,

which forms the cliffs along the rim of the Grand Canyon, is a Permian carbonate deposit.

Almost all of the geologic periods of the Paleozoic began with what?

with adaptive radiations, or times of rapid evolution of organisms

Phylum Mollusca

(Clams, oysters, snails, slugs, Nautilus, squid, octopus, cuttlefish) Name: Mollusca means " soft bodied". Chief characteristics: Soft body enclosed within a calcium carbonate shell (a few, like slugs and the octopus, have no shell). Muscular part of body of clams and snails and some other groups of molluscs is called the foot. Geologic range: Cambrian to Recent. Mode of life: Marine, freshwater, or terrestrial. They may: swim, float or drift, burrow into mud or sand, bore into wood or rock, attach themselves to rocks, or crawl.

CLASS GASTROPODA

(Snails and slugs) Name: Gastropod means "stomach" (gastro) + "foot" (pod). Chief characteristics: Asymmetrical, spiral-coiled calcareous shell. Geologic range: Early Cambrian to Recent. Mode of life: Marine, freshwater or terestrial.

LASS CEPHALOPODA

(Squid, octopus, Nautilus, cuttlefish) Name: Cephalopod means " head" (kephale) + " foot" (pod). Chief characteristics: Symmetrical cone-shaped shell with internal partitions called septae (singular = septum). Shell may be straight or coiled in a spiral which lies in a plane. Smooth or contorted sutures visible on the outside of some fossils mark the place where septae join the outer shell. Geologic range: Late Cambrian to Recent. Mode of life: Marine only; carnivorous (meat-eating) swimmers.

Phylum Echinodermata

(Starfish, sea urchins, sand dollars, crinoids, blastoids) Name: Echinodermata means "spiny" (echinos) + "skin" (derma). Chief characteristics: Calcite skeleton with five-part symmetry, superimposed on primitive bilateral symmetry. Echinoderms have a water vascular system with water in a system of tubes within the body. Tube feet are soft, movable parts of the water vascular system which project from the body and are used in locomotion, feeding, respiration, and sensory perception. Similarity of embryos between echinoderms and chordates suggests that they may be derived from a common ancestral form. Geologic range: Cambrian to Recent. Mode of life: Exclusively marine. Some are attached to the seafloor by a stem with "roots" called holdfasts; others are free-moving bottom dwellers.

SUBPHYLUM TRILOBITA

(Trilobites) Name: Trilobite means "three" (tri) + "lobed" (lobus). Chief characteristics: Body has a three-lobed appearance; two long grooves running from the head to the tail divide the body into three lobes. Skeleton composed of chitin, strengthened by calcium carbonate in places not requiring flexibility. Body is divided into three segments: Rigid head segment (cephalon), often with compound eyes. Jointed, flexible middle section (thorax). Rigid tail piece (pygidium). Geologic range: Cambrian to Permian - all extinct. Mode of life: Exclusively marine. Most were bottom dwellers living in shallow shelf environments.

CLASS SCAPHOPODA

(Tusk shells or tooth shells) Chief characteristics: Curved tubular shells open at both ends. Geologic range: Ordovician to Recent. Mode of life: Marine.

Early Paleozoic jawless fish

A group of armored jawless fishes called the ostracoderms (name means "shell skin") lived in the Early Paleozoic. The armor was made of bony material, and served as protection from predators or for storing seasonally available phosphorous. Bone is made of apatite, which contains phosphorous. Ostracoderms were mainly small, sluggish fish that were filter feeders or "mud strainers".

CLASS EDRIOASTEROIDEA (edrioasteroids)

A group that was probably ancestral to starfish and sea urchins. Globular, discoidal, or cylindrical tests (shells), many of which had concave surfaces. Geologic range: Early Cambrian to Middle Pennsylvanian.

A volcanic island arc or exotic terrane, called the Avalon terrane (or Carolina terrane), collided with what during the Devonian?

A volcanic island arc or exotic terrane, called the Avalon terrane (or Carolina terrane), collided with

This orogeny occurred in the Devonian as North America (Laurentia) and Europe (Baltica) collided to form Laurasia

Acadian

What was the Carboniferous named after?

Accumulation of plant remains in swamps produced the vast coal deposits

Continents during the Permian

All of the continents had collided and joined to form the supercontinent, Pangea.

This orogeny occurred as Gondwana collided with Laurasia (North America and Europe) during thr Late Carboniferous:

Alleghanian

SUBCLASS AMMONOIDEA

Ammonoid cephalopods have complex, wrinkled or crenulated septa, which produce angular or dendritic sutures. Geologic range: Devonian to Cretaceous - all extinct.

Parts of the amniotic egg

Amnion (or amniotic membrane) encloses the embryo in water (amniotic fluid). Allantois is a reservoir for waste and provides for gas diffusion. It becomes the urinary bladder in the adult. Chorion provides a protective membrane around the egg. Yolk is a storage area for fats, proteins, and other nutrients - food for the embryo. The amniotic egg provided freedom from dependency on water bodies, and helped the vertebrates live in diverse types of terrestrial environments. It is an important milestone in the evolution of vertebrates.

Ordovician Extinction

An extinction event at the end of the Ordovician led to an abrupt decline in diversity. This extinction event was apparently related to the growth of glaciers in Gondwana, coupled with a reduction in shallow water habitat associated with the lowering of sea level.

Ordovician jawless fish

Astraspis, an Ordovician jawless fish from the Harding Sandstone of Colorado.

Modes of life for Phylum Porifera

Attached to the seafloor. Most are marine

Mode of life for Phylum Archaeocyatha

Attached to the seafloor. Reef-builders.

Modes of life of Foraminifera

Benthic or benthonic (bottom dwellers) Planktic or planktonic (floaters)

CLASS BLASTOIDEA (blastoids)

Blastoids are extinct animals with an armless bud-like calyx on a stem. About 95 genera are known. A common genus is Pentremites. Geologic range: Ordovician to Permian - all extinct.

Phylum Brachiopoda

Brachiopods or lamp shells Name: Name means "arm" (brachio) + "foot" (pod). Chief characteristics: Bivalved (two shells), each with bilateral symmetry. The plane of symmetry passes through the center of each shell or valve. The two valves differ in size and shape in most. Sometimes the larger valve will have an opening near the hinge line through which the pedicle extended in life. Soft parts include a lophophore consisting of coiled tentacles with cilia. The lophophore circulates water between the two valves, distributing oxygen and flushing out carbon dioxide. Water movements caused by the lophophore also transport food particles toward the mouth. Geologic range: Lower Cambrian to Recent. Very abundant during the Paleozoic. A few species (belonging to only three families) remain today. Mode of life: Inhabitants of shallow marine environments; they generally live attached in a fixed position on the seafloor. Inarticulate brachiopods are known to live in burrows in the sediment. Brachiopods are filter feeders.

CLASS ARTICULATA - The Articulate Brachiopods

Brachiopods with calcareous valves attached together with a hinge consisting of teeth and sockets. Some of the more common articulate brachiopods are Pentamerus, Rafinesquina, Atrypa, Leptaena, and Spirife Geologic range: Lower Cambrian to Recent Spiny brachiopods (called productids) are characteristic of the Carboniferous and Permian.

CLASS OPHIUROIDEA (brittle stars)

Brittle stars have 5 arms, like starfish, but the arms are thin and serpent-like. About 325 genera are known. Geologic range: Ordovician to Recent.

Land Plants

Bryophytes - non-vascular plants - mosses, liverworts, and hornworts. Devonian to Recent. an eary non-vascular plant from the Devonian Reconstruction of an eary non-vascular plant from the Devonian. Tracheophytes - vascular plants - trees, ferns, and flowering plants. Silurian to Recent. Tracheophytes have vascular tissues, or an internal system of tubes and vessels, that transport water and nutrients from one part of the plant to another. A water transport system is important, because plants generally withdraw water from below the ground. Below the ground there is water but no light. Above the ground there is sunlight but there may not be water. The vascular system allows the plant to take advantage of both places. The oldest unquestioned vascular plant fossils occur in Silurian rocks (435-410 m.y. ago). They were small, leafless plants with thin branching stems. These plants are called psilophytes. Spore bodies are present on the ends of the stems in fossils of Cooksonia. Cooksonia Cooksonia, an early vascular plant in the Late Silurian and Early Devonian. Height was approximately 4 cm.

How did Pangea form?

By the Late Carboniferous, a large continental landmass called Pangea, had formed by the collision of Laurasia (North America plus Europe) with Gondwana (the southern continents of Africa, South America, Australia, Antarctica, and India).

Acadian Highlands during the Mississippian

By the Mississippian, the Acadian highlands were reduced in size by erosion, and were no longer releasing large quantities of sediment. In the east, near the remaining highlands, nonmarine shales, sandstones, and conglomerates were deposited. These sediments belong to the Pocono Group.

When did the Iapetus Ocean (or Proto-Atlantic), which was prominent in the Devonian, completely close?

By the late Carboniferous

Many factors contributed (or may have contributed) to the Permian mass extinction, including:

Climatic change associated with assembly of Pangea (global cooling and drying, along with interruption of equatorial circulation) Glaciation at both north and south ends of Pangea Reduction in epeiric or epicontinental seas (habitat loss) as sea level dropped Unusually active volcanism releasing CO2 (flood basalts in Siberia), leading to global warming, which may have triggered release of large stores of methane gas frozen in sediments on the seafloor, causing increased global warming. Possibility of an extraterrestrial impact, as indicated by spherical carbon molecules containing an extraterrestrial helium-3 isotope

Closure of the Iapetus Ocean caused what?

Closure of the Iapetus Ocean probably disrupted global ocean circulation and caused currents to be diverted from the tropics to more polar areas. If warm moist air was funneled from the tropics toward the poles, it may have contributed to glaciation.

A typical Pennsylvanian cyclothem contains ten units marking the transgressions and regressions of inland seas. The lower half of the cyclothem consists of nonmarine sediments, topped by what type of deposit?

Coal

Coal during the Pennsylvanian

Coal swamps formed along the western edge of the Appalachian Mountains, in what was basically a tropical rainforest setting.

The erosion of the Uncompahgre Mountains produced great wedge-shaped deposits of red arkosic sandstone during the Pennsylvanian and Permian (Fountain Formation), some of which is now exposed at the Garden of the Gods, Red Rocks Amphitheatre and the "flatirons" in which state?

Colorado

Phylum Archaeocyatha Chief characteristics:

Conical or vase-shaped skeletons made of calcium carbonate. Double-walled structure with partitions and pores.

Chief characteristics of conodont:

Conodont elements are microfossils (fossils that are so small that you need a microscope to examine them). Most conodont elements are 0.5 - 1.5 mm (some up to 10 mm, and some as small as 0.1 mm). They are composed of a calcium phosphate variety of the mineral apatite (calcium fluorapatite). Individual conodont elements resemble cone-shaped teeth, or consist of bars with rows of tooth-like denticles, or irregular knobby plates called platforms. Each conodont element is a part of a larger organism. Most fossil occurrences are of disassociated elements, but occasionally they are found arranged in specific patterns, assemblages or "apparatuses."

Meaning of conodont

Conodont means "cone" + "teeth" (dont)

What caused several orogenies or mountain-building events in eastern North America?

Continental Collision

Orogeny during the Permian

Continental collision was accompanied by orogeny, and the Appalachian mountain chain reached its peak during the Alleghanian Orogeny.

Cordaites - Class Pinopsida, Order Cordaitales

Cordaites are seed-bearing gymnosperms with strap-like leaves that were ancestors to the modern true conifers. They were tall trees (up to 50 m) that were abundant in Carboniferous coal swamps. Cordaites became extinct by the end of the Permian. Cordaites End of a branch of Cordaites showing the strap-like leaves.

Silurian Diversity

Diversification of marine animals occurred again at the beginning of the Silurian Period, and the period ended with only a slight drop in diversity.

Paleozoic Era

Divided into Early Paleozoic and Late Paleozoic characterized by long periods of sedimentation punctuated by mountain building Strata are relatively flat-lying to gently dipping, and warped into basins, domes, arches, and broad synclines.

Drying during the Permian

Drying of climates at low latitudes led to contraction of coal swamps and extinctions among spore-bearing plants and amphibians that required moist conditions

The amniotic egg is the key feature in the development of the reptiles. Characteristics of the amniotic egg:

Durable outer shell protects embryo from drying Egg can be laid on land Yolky part of egg provides nutrition; sac contains embryo and another sac collects waste products Eliminated need to lay eggs in water, allowing vertebrates to live and reproduce on dry land for the first time Amniotic egg probably evolved in Carboniferous First fossil eggs are Early Permian

"evolution's big bang."

During that episode of explosive evolution, all of the major invertebrate phyla (except the Bryozoa) appeared in the fossil record.

Cambrian plants

During the Cambrian, there were no vascular plants on the land, so the landscape was barren. Erosion would have been active and severe without plant roots to hold the soil.

Alleghanian Orogeny

During the Late Paleozoic, northwestern Africa collided with southeastern North America, causing the Alleghanian Orogeny, and building the Appalachian mountains.

Mississippian

Early Carboniferous

The Echinoderm-Backbone Connection

Echinoderms are closely related to chordates (the group that includes the vertebrates). The early cell division, embryonic development, and larvae of echinoderms resemble those of chordates, and are different from those of other invertebrates. Biochemistry of echinoderms is also similar to that of chordates (chemical similarities associated with muscle activity and chemistry of oxygen-carrying pigments in the blood).

CLASS ECHINOIDEA (sand dollars and sea urchins)

Echinoids are disk-shaped, biscuit-shaped, or globular. Viewed from above, they may be circular or somewhat irregular in shape, but with a five-part symmetry. About 765 genera are known. Geologic range: Ordovician to Recent.

Silurian Iron Ore

Economically important sedimentary iron ore deposits accumulated during the Silurian in the southern Appalachians, particularly around Birmingham, Alabama. Steel was produced for many years in Birmingham from this iron ore. Fuel was supplied by nearby Late Paleozoic coal deposits. Limestone, also found nearby, was used as flux in the blast furnace.

Therapsids Therapsids were small to moderate-sized animals with several mammalian skeletal characteristics, such as:

Fewer bones in the skull than the other reptiles Mammal-like structure of the jaw Differentiated teeth (incisors, canines, and cheek teeth) Limbs in more direct alignment beneath the body Reduction of ribs in the neck and lumbar regions, allowing greater flexibility Double ball-and-socket joint between the skull and neck Bony palate which permitted breathing while chewing (an important characteristic for animals evolving toward mammalian warm-bloodedness.) Efficient breathing provides oxygen needed to derive heat energy from food Whisker pits on the snout Mammal-like features are well developed in the therapsid, Cynognathus. (From "kynos" meaning "dog" and "gnathos" meaning "jaw" or "tooth.") Examination of the bone on the snout portion of the skull reveals probable "whisker pits", suggesting that they had hair, which may have functioned to insulate the animal and slow the rate of heat loss. Cynognathus Cynognathus crateronotus, a therapsid from the Early Triassic (230-225 m.y.), Cape Province, South Africa. Note the differentiated teeth. This animal was obviously a predator. Photo courtesy of Pamela Gore. Therapsids are found in Permian and Triassic rocks.

Late Ordovician Extinctions

Following a slight dip in diversity at the end of the Cambrian, the Ordovician was a time of renewed diversification. The number of genera increased rapidly, and the number of families increased from about 160 to 530. This increase was particularly dramatic among trilobites, brachiopods, bivalved molluscs, and gastropods. An extinction event at the end of the Ordovician led to an abrupt decline in diversity. The extinction occurred in two phases. First phase - affected planktonic and nektonic (floating and swimming) organisms such as graptolites, acritarchs, many nautiloids and conodonts, as well as benthic (bottom-dwelling) organisms such as trilobites, bryozoa, corals, and brachiopods. Second phase - affected several trilobite groups, corals, conodonts, and bryozoans. Both phases of the extinction event were related to global cooling and the growth of glaciers in Gondwana. Glaciation was coupled with the lowering of sea level and a reduction in shallow water habitat. As the climate cooled, tropical organisms showed the greatest decline. As warming occurred and the glaciers began to melt, organisms which were adapted to the cooler conditions began to suffer extinction. This was the second phase of extinctions.

Gymnosperms (conifers, cycads, ginkgoes, and various evergreen plants without flowers) - Phylum Pinophyta or Gymnospermophyta

Gymnosperms were seed-bearing plants rather than spore-bearing plants. They had no flowers. The word "gymnosperm" means "naked seed". Seed-bearing plants no longer require moist habitats. This led to the expansion of plants into drier areas. Geologic range: Middle Paleozoic to Recent.

The Chengjiang fauna

In 1984, the Lower Cambrian (535 m.y. old) Chengjiang fossil site was discovered in Yunnan Province, China. More than 100 species of invertebrates have been found, with extraordinary preservation, including many soft bodied forms.

Extensive salt beds were deposited where?

In Kansas

Siberia fossils

In the 1970s, a distinctive group of small shelly fossils was found below the first trilobites in Siberia and elsewhere, and dated at 544 my. This small shelly fauna includes sponge spicules, brachiopods, molluscs, and possibly annelids.

Paleozoic

Means ancient life 542-251 million years ago

Mesozoic

Means middle life 251-65.5 million years ago

Cenozoic

Means recent life 65.5 million years ago to the present

Phanerozoic

Means visible life 542 million years ago to the present Consists of three eras 1. Paleozoic 2. Mesozoic 3. Cenozoic

Amphibamus lyelli

Middle Pennsylvanian, North America

The Antler Orogeny continued into the what?

Mississippian and Pennsylvanian.

SUBCLASS ZOANTHARIA ORDER SCLERACTINIA - The Scleractinian Corals

Modern corals are scleractinian corals. Scleractinian corals have septae that are arranged in multiples of six, and are sometimes called hexacorals. Scleractinian corals did not appear until after the Paleozoic Geologic range: Triassic to Recent.

Early Paleozoic Sedimentary Sequences

Shallow epicontinental seas transgressed across the Laurentian (North American) craton during the Early Paleozoic as the glaciers melted and sea levels rose. The seas regressed as the glaciers enlarged and sea levels dropped.

Overview of Changes in Diversity Through Time

Most of the periods of the Paleozoic ended with extinction events The beginning of most of the periods of Paleozoic were marked by adaptive radiations Maximum diversity in the Paleozoic seas maintained roughly constant at between 1000 and 1500 genera, according to the graph above The largest extinction occurred at the end of the Permian Recovery of diversity in the Mesozoic was slow (Triassic and Jurassic) Diversity increased rapidly in the Cretaceous Another mass extinction occurred at the end of the Cretaceous Diversity increased with extremely rapidly, at unprecedented rates, at the beginning of the Cenozoic Diversity in the Cretaceous, and Cenozoic Era was much greater than during the Paleozoic

The Rugose Corals

Most rugose corals are solitary and conical (shaped like ice cream cones). Septae are visible in the circular opening of the cone. They are arranged in multiples of four, and are sometimes called tetracorals. Some rugose corals are colonial, having hexagonal corallites with septae (such as Hexagonaria from the Devonian of Michigan). Geologic range: Ordovician to Permian - all extinct. Rugose corals were abundant in the Devonian and Carboniferous, but became extinct during the Late Permian. Devonian solitary rugose coral Devonian solitary rugose coral. Note the radial septae within the theca (or circular cup). Colonial rugose coral Colonial rugose coral, Acervularia davidsoni, 365 my from the Devonian of Iowa.

North America during the Mississippian

Much of North America was covered by a shallow epicontinental sea. North America sat on the equator, so temperatures were warm

CLASS AGNATHA (jawless fishes, including the living lampreys and hagfishes as well as extinct ostracoderms)

Name: "A-" means "without", and "gnatha" means "jaws". Chief characteristics: Fish without jaws. Geologic range: Cambrian to Recent. Ostracoderms were Ordovician to Devonian. Mode of life: Swimmers. Jawless fishes are present in the Harding Sandstone (Lower Ordovician) of Colorado. Also found in Lower Ordovician rocks in Australia and Bolivia. Includes Astraspis.

CLASS AMPHIBIA

Name: "Amphi" means "both" or "double", and "bios" means "life". "Amphibios" means living a double life, referring to living in water and on the land. Chief characteristics and mode of life: Amphibians can live on the land as adults, but they lay their eggs in water. Young amphibians live in the water and are fish-like (tadpoles). Geologic range: Late Devonian to Recent. For 50 million years, from the Late Devonian to the Middle Carboniferous, amphibians were the only vertebrates to inhabit the land. Some adult amphibians reverted to an aquatic mode of life, while others retained a terrestrial lifestyle. In the Late Devonian (about 375 m.y. ago), the first terrestrial vertebrate, Ichthyostega, appeared. These amphibian fossils are found in freshwater deposits. "Ichthyo" means "fish" and "stega" means "roof" or "cover" (probably referring to the bones in the roof of the skull).

CLASS OSTEICHTHYES (bony fishes)

Name: "Osteo" means "bone" and "ichthyes" means "fish". Chief characteristics: Skeleton of bone, not cartilage. Modern bony fishes are of this type. The most numerous, varied, and successful of all aquatic vertebrates. Geologic range: Devonian to Recent. Well known in Devonian rocks. Mode of life: Swimmers. Marine and freshwater. The earliest lived in freshwater.

CLASS PLACODERMI (placoderms)

Name: "Placo-" means plate and "derm" means "skin". These are the "plate-skinned" fishes. Chief characteristics: Fish with jaws and armor plating. Geologic range: Late Silurian to Late Devonian. Extinct. Mode of life: Swimmers. Some were large carnivorous predators, such as Dunkleosteus, which grew to about 9 meters long

CLASS CHONDRICHTHYES (sharks, rays, and skates)

Name: From "chondros", meaning "cartilage", and "icthyes" meaning "fish". Chief characteristics: Cartilaginous fishes. Skeleton is made of cartilage and not bone, and so is rarely preserved. Geologic range: Middle Paleozoic (Late Silurian to Devonian) to Recent. Mode of life: Swimmers. Marine, except one genus that inhabited freshwater in the Late Carboniferous. The genus Cladoselache, is found in Devonian shales on the southern shore of Lake Erie.

CLASS REPTILIA

Name: From "reptilis" meaning "creeping". Chief characteristics: Two characteristics of the skull which can be used to distinguish reptiles from amphibians are: The reptile skull is high and narrow, compared with the low, broad amphibian skull. In reptiles, the roof of the mouth is arched, with small openings. In amphibians, it is flat with large openings. Mode of life: Complete colonization of land was achieved by the reptiles, which can lay their eggs on dry land. Geologic range: Pennsylvanian to Recent. The oldest reptile fossils, genus Hylonomus, (300 m.y. old) are found in Nova Scotia inside fossilized hollow trees filled with sediment. These reptiles were about 24 cm (about 1 ft) long. They resemble modern insect-eating lizards.

Late Paleozoic Seas

Shallow epicontinental seas transgressed and regressed across Laurasia (North America) during the late Paleozoic as the glaciers melted and enlarged. These sequences are bounded by (or separated by) unconformities.

Phylum Hemichordata CLASS GRAPTOLITHINA (Graptolites)

Name: Graptolite means "write" (grapto) + "stone" (lithos), because they resemble pencil marks on rock. Chief characteristics: Organic (chitinous) skeletons consisting of rows or lines of small tubes or cups, called thecae. Tubes or cups branch off a main cord or tube called a stem or stipe. Stipes may consist of one, two, or many branches. Entire colony called a rhabdosome. A filament at the lower end of the rhabdosome is called a nema. Most graptolites are found flattened and carbonized in black shales and mudstones. Geologic range: Cambrian to Mississippian. (Most abundant in Ordovician and Silurian.) Some living organisms which may be surviving descendants (living fossils) have been recovered in 1989 in the South Pacific and later in Bermuda. Mode of Life: Planktonic (colonies attached to floats). graptolites

CLASS MONOPLACOPHORA

Name: Monoplacophora means "single plate-bearer". Chief characteristics: Single shell resembling a flattened cone or cap. Soft part anatomy shows pseudo-segmented arrangement of gills, muscles, and other organs. Suggests that the primitive mollusc was a segmented animal. Segmentation was lost secondarily. Monoplacophorans are regarded as ancestral to bivalves, gastropods, and cephalopods. Geologic range: Cambrian-Recent, but only known as fossils from Cambrian to Devonian. Living monoplacophorans found in deep water off Costa Rica in 1952 and named Neopilina. Considered to be a "living fossil" .

Phylum Bryozoa

Name: Name means "moss" (bryo) + "animal" (zoa). Chief characteristics: Colonial (many microscopic individuals living physically united adjacent to one another). The individuals are called zooids, and they are housed in a hard "capsule" called a zooecium. The colony is called a zoarium. Individual zooecia (plural of zooecium) are very tiny (about the size of a pin-hole, a millimeter or less in diameter). They are just large enough to be seen with the unaided eye. Bryozoans may be distinguished from corals because of the apertures in the skeleton are much smaller. The bryozoan colony may resemble lace or a tiny net, may be delicately branching, finger-like, circular or dome-shaped. There are more than 4000 living species of bryozoans, and nearly 16,000 fossil species. Archimedes, from the Mississippian period, has a cork-screw-like central axis with a fragile net-like colony around the outer edge. fossil bryozoanfossil bryozoan Two specimens of the fossil bryozoan, Archimedes. Note the corkscrew-like central axis in both. In the second image, however, note the fragile lacy, net-like extension attached to the edges of the central axis. In life, the colony resembled a net wound into an erect spiral. Geologic range: Ordovician to Recent. Mode of life: Widespread in marine environments. A few live in freshwater lakes and streams. Colonies may be encrusting (a thin layer covering a rock or shell), erect (attached at the bottom and standing up like a tree - some are branching, others are sheet-like), or massive (compact and nodular).

Two major groups of vertebrates:

Non-amniotic vertebrates - Egg lacks a covering and must be fertilized externally. Must be wet or in water to reproduce. Amniotic vertebrates - Amniotes. Internal fertilization and an amniotic egg (enclosed egg). Water is not required for reproduction.

North America during the Silurian

North America (Laurentia) still sits on the equator, but there is a huge landmass (Gondwanaland) in the southern hemisphere, at or near the South Pole.

North America during the Devonian

North America sat on the equator, with warm, tropical climatic conditions

Conodont elements

Note that the color is indicative of thermal history and burial temperatures. Darker color indicates higher temperature. Temperatures are important to determine whether petroleum may have been generated in the rock, or whether temperatures were too high for petroleum to be preserved.

Orogenies affect on climate during the Permian

Orogenies probably also affected the climate. Locations of mountains can affect climate and control precipitation (rain-shadow effect). Deserts form on the downwind side of mountain ranges.

The Chattanooga Shale is a thin, but extraordinarily widespread, black or dark gray shale with lacks fossils of bottom-dwelling invertebrates, and which contains uranium, finely disseminated pyrite and organic matter. These characteristics indicate that it accumulated in what type of depositional environment?

Oxygen-deficient sea water

The supercontinent that assembled during the Late Paleozoic was called:

Pangea

Pangea was surrounded by a huge ocean called what?

Panthalassa

The amniotic egg provided a new way of reproduction without returning to the water. The oldest fossil amniotes have been found in coal swamp deposits of this age:

Pennsylvanian

The Delaware basin and other basins in West Texas and New Mexico had reefs around the edge, and were associated with evaporite deposits. What age are these Late Paleozoic basin deposits that are now exposed in the Guadalupe Mountains?

Permian

This unusual type of deposit formed in a relatively deep marine basin in Montana, Idaho, Utah and Wyoming during the Permain:

Phospherite

Classification of Molluscs

Placophorans are primitive molluscs with multiple paired gills, and a " foot" like that in snails. This group includes both the monoplacophorans and the polyplacophorans (chitons).

Mode of life for Radiolara

Planktonic. Marine only.

Subphylum Cephalochordata

Primitive chordates. Lancelets, Branchiostoma, Amphioxus. Small marine animals with fish-like bodies and notochord. Branchiostoma Branchiostoma, a non-vertebrate chordate. Length 3 - 5 cm. Chief characteristics: Lancelets resemble a small, colorless anchovy fillet, without obvious eyes or lateral fins. Worm-like. Has segmented axial muscles, gill slits, a dorsal hollow nerve cord, a notochord, and a post-anal tail. There is nothing resembling a vertebral column. No solid skeleton. Geologic range: Cambrian to Recent. Mode of life: Bottom dwellers. Lancelets spend much of their time burrowing in the sand in warm, coastal, marine environments. Filter feeders. Relatively sessile but capable of swimming. Significance: An ancestor to the vertebrates resembled a lancelet-like creature.

Subphylum Urochordata

Primitive chordates. Sea squirts, ascidians, or tunicates. Larval forms have notochord in tail region. Chief characteristics: Adults have sac-like bodies, ranging in size from less than 1 mm to a few cm. Larval form resembles a tadpole and has a notochord, dorsal tubular nerve cord, gill slits, and post-anal tail. Geologic range: not known Mode of life: Inhabit overhangs or shaded areas in the low intertidal and subtidal zone. Most live attached as adults. Filter feeders. Behavior resembles that of a sponge. Body contracts abruptly expelling water, giving them the name "sea squirts".

Radiolara chert

Radiolarians are important constituents of chert at certain times in geologic history. Their tests accumulate on the seafloor today to form radiolarian ooze, particularly in deep water, where any calcium carbonate shells would be dissolved.

There are two types of crossopterygian fish:

Rhipidistians - this group led to the amphibians Coelacanths - Another group of lobe-finned crossopterygian fish invaded the sea and gave rise to the coelacanths. The coelacanths are considered to be living fossils because they were long-believed to be extinct, but one was caught in 1938 near Madagascar. More have been caught since.

Late Mississippian

Sands, clays, and thin layers of carbonates were deposited in Late Mississippian time as the Kaskaskia sea regressed. These rocks are a source of petroleum in Illinois. They appear to have been deposited in stream valleys developed on the former seafloor.

Two major transgressions occurred during the Early Paleozoic in North America:

Sauk sequence (older - primarily Cambrian) Tippecanoe sequence (Ordovician-Silurian

CLASS ARACHNIDA (scorpions, spiders, ticks, and mites)

Scorpions are the oldest arachnids with a fossil record. Scorpions had evolved by the Late Silurian. The earliest ones appear to have lived in the water, because their fossils have gills. Scorpions, spiders, and mites are found in Devonian rocks. Geologic range: Late Silurian to Recent.

CLASS HOLOTHUROIDEA (sea cucumbers)

Sea cucumbers are soft-bodied echinoderms resembling cucumbers. They have microscopic hard parts called sclerites in various shapes resembling hooks, wheels and anchors. About 200 genera are known. Geologic range: Middle Cambrian?, Middle Ordovician to Recent

Devonian Sea levels

Sea levels were fairly high worldwide during the Devonian (indicating that there were no glaciers). Much of the North American continent was flooded by shallow seas.

How are evaporite minerals precipitated.

Sea water flows into the basin over the partially-submerged barrier. Evaporation produces dense brines, which sink to the bottom of the basin and are unable to mix with open sea water. When the brine becomes sufficiently concentrated, evaporite minerals are precipitated.

Sediments in the Appalachian Mtns during the Pennsylvanian

Sediment eroding from the Appalachian Mountains was transported to the west into the epicontinental sea that covered much of North America during the Mississippian Period. These sedimentary deposits have built a broad plain to the west, with alternating non-marine and marine deposits, as the sea transgressed and regressed

Seed ferns - Class Pteridospermophyta

Seed ferns had fernlike leaves, but unlike true ferns, they reproduced with seeds instead of spores. Geologic range: Devonian to Recent. Common genera in the Carboniferous were Neuropteris and Glossopteris. One of the best-known seed ferns is Glossopteris, which was restricted to the Gondwanaland continents during the Carboniferous and Permian. They are "tongue-shaped", and are sometimes associated with glacial deposits, suggesting that they were adapted to cool climates.

Major Advances in Land Plants Three major advances occurred in land plant history, each involving the development of increasingly more efficient reproductive systems:

Seedless spore-bearing plants, appearing in the Ordovician, and flourishing in Carboniferous coal swamps Seed-producing, pollinating, but non-flowering plants appearing in the Late Devonian (gymnosperms, such as conifers) Flowering plants, appearing in the Late Mesozoic (angiosperms)

mass extinctions

Several mass extinctions occurred during the Paleozoic, including the largest extinction of all at the end of the Paleozoic Era (Permian period). Other mass extinctions occurred at the end of the Ordovician and Devonian periods.

Pelycosaurs

Several species of pelycosaurs had fins or "sails" on their backs, supported by rod-like extensions of their vertebrae. These sails may have been used as temperature regulating mechanisms. Two well known pelycosaurs, which evolved their sails independently were the carnivorous Dimetrodon, and the plant-eating Edaphosaurus. Edaphosaurus The Permian pelycosaur, Edaphosaurus. Photo courtesy of Pamela Gore. Dimetrodon has a larger skull and teeth than does Edaphosaurus, suggesting that Dimetrodon was a meat eater. Pelycosaurs lived in the Carboniferous and Permian. The sail-backed forms are characteristic of the Permian.

Sedimentary deposits of the Pennsylvanian Period are characterized by:

Shales, Sandstones and Coal Beds

Neopteroplax

Skull of Neopteroplax, 290 m.y. ago, aquatic amphibian from the Late Carboniferous of Ohio. Features suggesting an aquatic lifestyle include a flattened body and skull, reduced limbs, and a slender snake-like body.

Modern walking, air-breathing fish in the U.S.

Some fish today have lungs and can walk on land. The snakehead fish, Channa argus, native to parts of Asia and Africa, made news in 2002 when they were found in a pond in Maryland, and subsequently in the Potomac River near Washington, D.C. They were originally purchased live in a fish market in New York's Chinatown, and later released into the wild, where they began to reproduce rapidly as a non-native species with no natural predators. They are capable of breathing air using an air bladder that works like a primitive lung. They are also capable of moving short distances on land using their pectoral fins. These fish can live out of water for 3 to 7 days. They can hibernate in cracks during cold weather, and become dormant in burrows in the mud during droughts. Snakeheads are predators at the top of the food chain. Florida also has "walking catfish", Clarias batrachus, that can breathe air. They are also non-native fish, and were accidentally introduced in the 1960's when they walked away from a fish farm. Both of these fish are in Class Actinopterygii. They are not closely related to the Devonian lungfish.

During the Late Paleozoic South America...

South America collided with the Gulf Coast region of North America, forming the Ouachita Mountains, a southwestern continuation of the Alleghanian orogenic belt.

Sphenopsids (horsetails, scouring rushes) - Phylum Equisetaphyta or Sphenopsida

Sphenopsids (like Calamites) were spore-bearing and similar to living horsetails or scouring rushes. They are often interpreted as living in moist areas, even perhaps standing water. Geologic range: Devonian to Recent. Few exist after the Permian.

Permian Mtn ranges

The Appalachian mountains are present in the east and the Ouachita mountains are in the southeast. Farther west are the "Ancestral Rockies." The Antler Mountains have been eroded down, and are now called uplands. Subduction and volcanism continue to be active in the far west.

CLASS ASTEROIDEA (starfish)

Starfish are star-shaped echinoderms with five arms. About 430 genera are known. Geologic range: Ordovician to Recent.

Two types of bony fish are significant:

Subclass Actinopterygii - the ray-finned fish. Dominant fishes in the world today. No muscular base to the paired fins. Fins are thin structures supported by radiating rods or rays. First appeared in Devonian freshwater lakes and streams, and then expanded their geographic range to the sea. Subclass Sarcopterygii - the lobe-finned fish or lungfish. The lobe-finned fishes appeared in the Late Devonian. Leg-like fins: Fishes with sturdy, fleshy lobe fins. These were leg-like muscular fins which they used to "walk" about on pond or stream bottoms. Lungs: They had a pair of openings in the roof of the mouth that led to nostrils. They were able to rise to the surface and breathe air with lungs when the water became foul or stagnant. Some had both lungs and gills. This group gave rise to the amphibians and other tetrapods (four-legged animals).

Organisms most strongly affected (but not totally wiped out) by the Devonian extinction were:

Tabulate corals Rugose corals Stromatoporoids Brachiopods Goniatite ammonoids (cephalopod molluscs) Trilobites Conodonts Placoderm fish

SUBCLASS TABULATA - The Tabulate Corals

Tabulate corals are colonial and resemble honeycombs or wasp nests. They lack septae. Instead, they have horizontal plates within the theca called tabulae. Tabulae are one of the main features of the tabulate corals. Skeletal structure of a colonial tabulate coral Skeletal structure of a colonial tabulate coral. An indivudual coral polyp lives in each vertical tube (called a theca). The theca has horizontal plates called tabulae, which give the coral its name. Geologic range: Ordovician to Permian - all extinct. Tabulate corals were the principal Silurian reef formers. They declined after the Silurian and their reef-building role was assumed by the rugose corals.

The three mountain-building events (or orogenies) in North America during the Paleozoic are:

Taconic orogeny Acadian orogeny Alleghanian orogeny

theca

The "cup," in which an individual coral polyp sits

Absaroka sea during the Pennsylvanian

The Absaroka sea began to transgress upon the North American craton near the beginning of the Middle Pennsylvanian period.

Acadian highlands during the Devonian

The Acadian highlands in eastern North America (orange), form a continuous belt with the Caledonian Mountains adjacent to Greenland and Europe.

How did the Appalachian Mtns form?

The Appalachian Mountains have formed as a result of the collision of Laurasia (North America) with the part of Gondwana that we now call Africa.

Late Devonian Extinctions

The Late Devonian extinctions occurred over a span of about 20 million years, and appear to have been the result of an ecological crisis in the seas, perhaps induced by changes occurring on the land. The Devonian was the time of the appearance of trees and spread of land plants. This would have accelerated weathering rates, leading to large volumes of nutrients being washed into the seas. Large quantities of nutrients in the water (such as phosphorus) causes algal blooms, or rapid algal growth. Bacteria breaking down large quantities of dead algae uses up all of the oxygen in the water, causing anoxic conditions (= "without oxygen"). This process is called eutrophication, and it occurs today in lakes, and causes massive "fish kills". Extensive Devonian black shale deposits (for example, the Chattanooga Shale) suggest the widespread occurrence of anoxic conditions in the Devonian sea. Glaciation may have been an additional contributing factor. By the Late Devonian, South America had drifted over the South Pole, and glaciations occurred. Overall, 70% of marine invertebrate families went extinct in the Late Devonian.

Late Permian Extinction Event

The Late Permian is marked by a catastrophic extinction event which resulted in the total disappearance of many animal groups. This was the largest extinction event in the history of life, exceeding even the extinction event at the end of the Cretaceous, which killed the dinosaurs. More than 90% of all marine species that existed in the Permian disappeared or were severely reduced in number. Nearly half of the known families disappeared. Tropical forms experienced the most extensive losses.

Seas in the Late Permian

The Late Permian was a time of widespread regression of the seas. The global map above indicates that sea levels were low worldwide. The vast epicontinental seas that once covered North America and parts of other continents were gone.

Types of corals are distinguished by presence or absence, and number of septae:

The Paleozoic rugose corals (or tetracorals) have septae arranged in multiples of four. The Mesozoic and Cenozoic scleractinian corals (or hexacorals) have septae arranged in multiples of six. The Paleozoic tabulate corals lack septae. Instead, they have horizontal plates within the theca called tabulae. Tabulae are one of the main features of the tabulate corals. Corals may be distinguished from the bryozoans (which are also colonial) based on the size of the corallites; in bryozoans, the apertures are much smaller; generally 1 millimeter in diameter or less. Geologic range: Late Precambrian (Proterozoic) to Recent for the phylum. The first corals were the tabulates. Mode of life: Corals live attached to the seafloor, primarily in warm, shallow marine environments.

Order Crossopterygii or crossopterygians

The ancestors of the amphibians. This group is considered to be ancestral to the amphibians because of the arrangement of bones in their fins, the pattern of bones of the skull, and the structure of their teeth. Short, muscular, paired fins. Had a single basal limb bone called the humerus, followed by the radius and ulna in front fins, and followed by the tibia and fibula in hind fins. (Same bones as in humans, chickens, and other vertebrates with four limbs.) The adaptation assisted movement in shallow water, and allowed the animal to move from a body of water that became too shallow or stagnant, to search for another body of water. Eusthenopteron belongs to this group.

Cambrian trace fossil

The base of the Cambrian is now placed at the oldest occurrence of feeding burrows of the trace fossil Phycodes pedum, and dated radiometrically at 542 my using uranium-lead isotope dates from rocks in Oman coinciding with a chemical anomaly known as the "negative carbon-isotope excursion."

ORDER BELEMNOIDEA (belemnites)

The belemnoids have an internal calcareous shell (which resembles a cigar in size, shape, and color) called a rostrum. The front part of this shell is chambered, as in the nautiloids and ammonoids. The rostrum is made of fibrous calcite, arranged in concentric layers. Geologic range: Mississippian to Eocene - all extinct.

What ARE conodonts?

The conodonts were previously placed in a separate phylum (Phylum Conodonta), because their affinities were unknown. The current interpretation places them with the Chordates in Phylum Chordata.

Cambrian desposition

The deposition of carbonate sediments in the central US during the Cambrian is exactly what would be expected. The presence of stromatolites and mudcracks in these carbonate rocks indicate deposition in shallow water.

"Cambrian substrate revolution."

The dramatic change in the character of the seafloor sediments (from undisturbed to highly burrowed)

Stromatolites - A Photosynthetic Plant Ancestor

The earliest photosynthetic organisms were in the sea. Stromatolites, built by photosynthetic bacteria (cyanobacteria, sometimes called blue-green algae), were ancestral to the Paleozoic plants. (They were not plants themselves.) Kingdom Eubacteria. Stromatolites appeared in the Archean, expanded during the Proterozoic, and are present in limestones of the Phanerozoic. Most Precambrian stromatolites grew in shallow marine and intertidal environments, but some lived in freshwater. Stromatolite reefs were widespread during the Cambrian, but declined in the Ordovician. They are typically found in areas lacking marine invertebrates, which feed on the cyanobacterial mats. The appearance of abundant marine invertebrates in the Cambrian led to the decline of the stromatolites. Why? They ate them.

East 2/3 of North America during the Permian

The eastern two-thirds of North America consisted of lowlands, undergoing erosion. Continental red beds were deposited locally.

Marine Algae

The next step in the evolutionary path to land plants was probably the green algae or chlorophytes, belonging to Kingdom Protista. Marine algae fossils are found in some Paleozoic rocks. Chlorophytes - Green algae. Cambrian to Recent. A close relationship between chlorophytes and land plants is suggested by the adaptation of some species to freshwater bodies and moist soil. Receptaculitids are lower Paleozoic marine fossils resembling sunflowers. They are produced by organisms of uncertain affinity, but interpreted as lime-secreting algae. Most are found in the Ordovician, but they are also present in the Silurian and Devonian.

The Fishes

The oldest known fish is from the Cambrian of China (about 535 m.y. old), found in the Chengjiang fossil site in Yunnan Province, There are five classes of fishes. Agnathids or jawless fish Acanthodians or spiny fish with jaws. Extinct. Placoderms or plate skinned fish with jaws. Extinct. Chondrichthyes or fish with cartilaginous skeletons, including sharks, rays, and skates. Osteichthyes or bony fishes. Most modern fish. Led to evolution of tetrapods. Geologic ranges of the five classes of fishes Geologic ranges of the five classes of fishes. The width of the red/orange area indicates the approximate relative abundance of each class.

Other uplifts also formed, including the Zuni-Fort Defiance uplift, the Amarillo mountains, and the Oklahoma mountains (represented today by the Arbuckle and Wichita mountains).

The origin of these mountains may be related to the collision of Gondwana along the southern edge of the North American craton in the Ouachita orogenic belt. Crustal adjustments to relieve stress may have resulted in the deformation that produced the highlands and associated basins (such as the Early Pennsylvanian Paradox basin, which contains evaporites and petroleum deposits).

CLASS OSTRACODA (ostracodes, also spelled ostracods)

The ostracodes are mainly microscopic in size. They consist of a tiny bivalved shell encasing a shrimp-like creature. Geologic range: Cambrian to Recent. Mode of life: Both marine and freshwater.

Late Carboniferous Climate

The presence of evaporites (E) indicates that the climate was at least locally dry. This was probably due in part to changes in global oceanic and atmospheric circulation induced by the closure of the Iapetus, as well as by orogeny.

East US rocks during the Pennsylvanian

The rocks in the eastern half of the US are predominantly interbedded marine and nonmarine sediments, indicating the advance and retreat of the sea. Each nonmarine-marine sequence is called a cyclothem.

Seas around continents

The seas regressed from the continents at the end of the Early Paleozoic as a result of the Ordovician-Silurian glaciation.

SUBCLASS NAUTILOIDEA

The shells of nautiloid cephalopods have smoothly curved septa, which produce simple, straight or curved sutures. Geologic range: Cambrian to Recent.

Size of Queenston Clastic wedge

The size of the clastic wedge suggests that the mountains may have been more than 4000 m (13,100 ft) high.

corallites

The skeletal parts formed by polyps

SW North America during the Pennsylvanian

The southwestern part of the North American craton experienced mountain building during the Pennsylvanian. The highlands are called the Uncompahgre Mountains (or ancestral Rockies) in southwestern Colorado, and the Oklahoma Mountains of western Oklahoma. The word "Uncomphagre" is a Ute Indian word meaning "hot water spring." These mountains and related uplifts resulted from movement along large, nearly vertical faults.

Where was Pangea

The supercontinent, Pangea, sat over the South Pole. When a continent is over a pole, conditions are right for a glaciation, if the climate is cold and if sufficient moisture is present.

CLASS SYNAPSIDA

The synapsids had diverged from the reptiles by the Late Carboniferous. The synapsids were long considered to be a subclass of reptile, but more recent cladistic analysis shows that they diverged from ancestors completely different than Hylonomus and other true reptiles. The synapsids were the dominant terrestrial vertebrate in the Permian. This group was formerly called the "mammal-like reptiles", however the name has been abandoned because they are not really reptiles. Synapsids include the pelycosaurs and the therapsids.

transgressive-regressive sequences

The transgression and regression of the seas deposited sequences of sedimentary rocks that reflect the deepening and shallowing of the waters.

cratonic sequences.

The unconformities can be used to correlate particular sequences from one region to another. The unconformity-bounded sequences are sometimes called these

Subphylum Vertebrata - The Vertebrates

The vertebrates are animals with a segmented backbone consisting of vertebrae, a definite head with a skull that encloses a brain, a ventrally-located heart, and well-developed sense organs. The notochord is supplemented or replaced by cartilaginous or bony vertebrae. Arches of the vertebrae encircle and protect a hollow spinal cord. Mode of Life: Includes both water-dwelling and land-dwelling tetrapods (from the Latin, meaning four feet). Some walk on four legs and some walk only on the hind legs (bipedal). In some, forelimbs are modified into wings. In some, the limbs have been modified into flippers. Geologic range: Cambrian to Recent.

Cambrian water around continents

The water deepens toward the edges of the continent, where deep water shale is deposited (blue-green). Sand is deposited along the edge of the exposed land mass (yellow).

great Mississippian lime bank.

The widespread blanket of carbonate rocks deposited during this time

Conifers - Class Pinopsida, Order Coniferales

The word "conifer" means "cone bearing". These trees contain cones which contain their seeds. Today the conifers are represented by trees such as pines, cedars, hemlocks, spruces, firs, redwoods, and many others. Conifers spread widely during the Permian, perhaps as a result of the drier conditions which led to the demise of the coal swamps. Ginkgoes - Class Ginkgopsida Gingkoes are deciduous trees (that drop their leaves) with fan-shaped leaves. They produce a fleshy fruit but have no flowers. Geologic range: Early Permian to Recent. They attained maximum diversity in the Jurassic, and are represented by a single species today, Ginkgo biloba. It is extinct in the wild, but is widely grown as an ornamental tree.

Mississippian eastern North America

There was an extensive landmass in eastern North America and Europe (yellow), formed as the mountains (orange) eroded after the Caledonian and Acadian orogenies. The land was built out through the deposition of non-marine sediment to the west of the mountain range.

Queenston Delta sediments do what

These red deltaic sediments coarsen and thicken to the east (toward the mountainous source area), and become thinner and finer grained to the west.

What happened as the Taconic mountains belt eroded?

Upper Ordovician to Lower Silurian red sandstones and shales were deposited to the west in huge delta systems. These sediments formed a wedge-shaped deposit known as the Queenston clastic wedge, or the Queenston delta.

Cratonic sequences correspond to

Vail curves of global sea level change

Distinguishing vertebrates

Various groups of vertebrates can be distinguished on the basis of the position and number of openings behind the eye on the side of their skulls.

Phylum Chordata

Vertebrates, sea squirts or tunicates, lancelets such as Amphioxus. Name: "Chord" means "string", referring to the nerve cord and/or notochord. Chief characteristics: Chordates have the following features at some point in their life (although in some cases, these features may be present only in the embryo): Bilateral symmetry. Gill slits. These slits are a series of openings that connect the inside of the throat to the outside of the "neck". Dorsal nerve cord (sometimes called a spinal cord). The nerve cord runs down the "back", connecting the brain with the muscles and other organs. Notochord. A stiff cartilaginous rod which supports the nerve cord. Post-anal tail. This is an extension of the body past the anal opening. Blood that circulates forward in a main ventral vessel and backward in a dorsal vessel. Geologic range: Cambrian to Recent. Mode of life: Varied. Among the vertebrates alone, various members are land dwellers, swimmers, or fliers. Paleozoic vertebrates were initially in the sea, but later colonized freshwater and land.

The first animals to invade the land were:

arthropods (millipedes and centipedes)

Where are The small shelly fossils found?

at the base of the Cambrian, but are also found in the late Neoproterozoic. Most disappeared by the end of the first stage of the Lower Cambrian.

Which is considered to be a contributing factor to the mass extinctions in the Permian?

climatic change regression of epicontinental seas and decrease in shallow water habitat volcanic activity assembly of continents into Pangea

Distribution of Permian sedimentary rocks used as:

climatic indicators

jellyfish

cnidarians with the medusa body form.

Sea anemones

cnidarians with the polyp body form. Note the ring of tentacles and the central mouth.

The Pennsylvanian is dominated by what?

coal-rich sedimentary rocks deposited in swamps and deltas. Coal deposits are particularly well developed in Pennsylvania.

Sponges appear to have evolved from what?

colonial, flagellated, unicellular organisms

The microscopic hard parts of this organism are used as guide fossils in Paleozoic sedimentary rocks, although the animal from which they came, and their function in the organism have been somewhat unclear until recently.

conodonts

Carboniferous Period

consists of the Mississippian and Pennsylvanian Periods in North America.

Accumulation of such a great thickness of evaporites requires what?

continual addition and evaporation of sea water, indicating that the isolated basin was connected to the open sea. This type of basin is called a barred basin. It is a restricted basin because it has a bar or sill between it and the open sea.

diachronous

cut across time lines

Because of the drying, ________ (seed plants, including conifers) replaced many spore-bearing plants, which require moist conditions.

gymnosperms

Foraminifera means

hole bearer", referring to holes in the test between chambers

The distribution of the glaciers can be determined from:

locations which have Permian glacial sedimentary deposits (tillites), as well as striations or scratches on the bedrock, caused by the movement of the glaciers.

Cold air (associated with the glaciation) holds less what?

moisture than warm air, and the climate became arid during the Permian.

Shallow water deposition is indicated by the presence of what?

mudcracks and stromatolites.

Synapsida (lower hole only)

pelycosaurs, therapsids, and mammals

The synapsids with sails on their backs, which were possibly used to regulate their body temperatures, were called:

pelycosaurs

The effects of the Acadian orogeny

seen in a belt extending from Newfoundland to West Virginia, where thick sequences of sedimentary rocks are interbedded with rhyolitic volcanic rocks and granitic intrusions.

The Paleozoic was a time of what?

several adaptive radiations and extinctions

Gulf Coast area during the Late Mississippian

slow deposition continued from Early Devonian to Late Mississippian Carbonates predominated in the more northerly shelf zone. Cherty rocks called novaculites were deposited in deeper waters to the south. Novaculites are composed of microcrystalline quartz, which has been subjected to heat and pressure. Arkansas novaculite is used as a whetstone to sharpen steel knives and tools.

Fossils of the earliest animals with shells included:

small tubular or cap-shaped shells

The first animals with shells are called what?

the small shelly fossils.

At the end of the Paleozoic, these continents collided again to form...

the supercontinent, Pangea.

After the Acadian orogeny in the Appalachian region, carbonate sedimentation was followed by the deposition of clastic sediments. The clastic sediments are:

thicker and coarser to the east, nearer their source area in the Acadian highlands. They are primarily continental red beds (stream deposits) and they form a wedge-shaped deposit called the Catskill clastic wedge or Catskill delta (although these are not deltaic deposits). The reddish brown sandstones of the Catskill are used in building the "brownstone" buildings in cities in the eastern US.

Grand Canyon region has what type of sequence

transgressive

Identify this Paleozoic fossil organism:

trilobite

Reefs and carbonates indicate what about the Devonian?

warm climate, and evaporites suggest dry conditions.

Silurian Orogenic activity (mountain building)

was more or less continuous at one place or another during the Silurian and Devonian. The Caledonian orogeny was most intense in Norway, as the Iapetus Ocean closed. The folded rocks of the Caledonians end in Ireland, but can be traced to northeastern Greenland, Newfoundland, and Nova Scotia, Canada.

Comparison of global distribution of continents during the Ordovician and Silurian shows what?

water depths and presence of evaporite deposits (E).