Invertebrates
In what period did Hydnoceras form extensive reefs?
Late Devonian
What do scientists think Receptaculites was formed by?
Many scientists now think that Receptaculites was formed by a calcareous algae
What are Massive Bryozoa?
Massive Bryozoa are also sometimes called "stony" "solid" or "domal" bryozoa bc their morphology is often large, flat sheets or lumps, Prasopora is considered a massive bryozoa
What period is the Brain coral from?
Mesozoic-Cenozoic (Jurassic - Recent)
What period does Scleractinia belong to?
Mesozoic-Cenozoic (Triassic-Recent) -- he scleractinian corals have been around since the Triassic period of the Mesozoic
What's the size of most specimens?
Most specimens are a few inches to a foot in diameter
What size are Archaeocyathids?
Most were small (1-3 cm diameter at the top and about 5 cm tall) but some grew much bigger
What is the common name for fungia?
Mushroom coral
What area is the fossil sponge Astylospongia common to?
North America
What area is Astraeospongia commonly found in?
North America (a distinctive North American fossil sponge)
What are "Petoskey Stones"?
PEtoskey stones are pebbles of colonial regose coral (Genus Hexagonaria) found along the shores of Lake Michigan. The fossil coral peices have been rounded and smoothed by wave action
What is Pachyphyllum?
Pachyphyllum is a common colonial rugose coral with distinctive morphology
What is the geologic age of the encrusting bryozoa specimens that we have?
Paleozoic
What period are the fenestrate bryozoa on the rock slab specimen we have from?
Paleozoic
What period is Receptaculites from?
Paleozoic
What period are Archaeocyathids from?
Paleozoic (Cambrian)
What geologic age does Pachyphyllum belong to?
Paleozoic (Devonian)
What geologic time period is Hexagonaria from?
Paleozoic (Devonian)
What geologic period are Favosites from?
Paleozoic (Ordovician - Devonian)
What geologic period are Tabulata from?
Paleozoic (Ordovician - Permian)
What time period is Prasopora from?
Paleozoic (Ordovician)
What is the geologic age of Rugosa (Order)?
Paleozoic (Ordovician-Permian)
What period are Stromatoperiods from?
Paleozoic - Mesozoic (but most common in the Paleozoic)
What's the state stone of Michigan?
Petoskey Stones!
What geologic period did Archimedes live?
mid-late Paleozoic
What is the average size of a Stromatoperoid specimen?
most specimens are about 10 cm (4 inches) across but some grew to several meters in width
Why are fossil sponges difficult to identify?
non-distinct morphology, complete fossils not common
What is the function of the Demosponges morphological features? Based on the form and function of other phyla, would this form and function have been predicted? Explain.
pg 304
What does the "Hex" in Hexactinellida refer to?
pg 306
How could you distinguish a fossil demosponge containing siliceous spicules from a fossil glass sponge?
pg 306-307
What mode of preservation sometimes takes place in Prasopora?
recrystallization in some of the specimens (large radiating crystals) - the large, darker specimen has been recrystallized and replaced (some of the calcium carbonate has been replaced by geothite, an iron-bearing mineral)
What is the morphology of Astylospongia?
roughly spherical, slight depression at the top, surface of these fossil sponges are grooved and pitted with pores (though difficult to see due to weathering)
What is the morphology of Astraeospongia?
saucer-shaped sponge with a distinct star pattern to spicules, it appears that each spicule has 6 rays but in fact each has 8! Two of the rays are reduced in size and oriented perpendicular to the six larger rays (see pg 307)
What does "Fenestra" mean in latin?
"Fenestra" is "window" in Latin and the open meshwork of the fenestrate bryozoa is distinctive latticed pattern
What is the common name of the rugose corals?
"Horn Coral"
What's the common name for branching bryozoa?
"Stick Bryozoa"
What is another name for demosponges
"common sponges"
What's the common name for Prasopora?
"gumdrop bryozoa"
What's the common name for favosite?
"honeycomb coral" due to the closely packed polygonal corallites that resemble a honeycomb
What is the common name for fenestrate bryozoa?
"latticed bryozoa" or "fan bryozoa"
Are Stromatoperoids reef-builders?
As benthic epifauna, stromatoperoids were common reef-builders in the Paleozoic
What's the common name of Receptaculites? and why?
Because the pattern of spiraling plates resembles the head of a sunflower, the common name is "sunflower fossil"
What were the most common tabulate corals during the Paleozoic?
Favosites and other members of the Favositidae family
What is the morphology of Receptaculites?
distinguished by its surface pattern of calcareous plates, one set of plates spiral counterclockwise and they intersect with another set of plates that spiral clockwise
What does the corallum (coral colony) of the tabulate corals consist of?
many closely spaced corallites (individual tubes). The tubes may be circular, elliptical, or polygonal in cross section
What are Tabulate corals?
- common Paleozoic fossils - skeletons of calcium carbonate (calcite) - not as diverse as the rugose corals (there were about 300 genera of tabulate corals compared to about 800 genera of rugose corals) - marine benthic animals that formed large masses of limestone and they were one of the most important reef-builders of the Silurian and Devonian
What is the composition of the spicules of Astraeospongia?
--
Why did brain corals live in shallow water?
---
What Phylum are Stromatoperoids a part of?
? Phylum, an enigmatic group
What Phylum is Receptaculites a part of?
? Phylum, an enigmatic group
What phylum are Archaeocyathids a part of?
? Phylum, an enigmatic group
What kind of Bryozoa is Archimedes?
Archimedes is a fenestrate Bryozoa?
What is Archimedes characterized by?
Archimedes is characterized by a distinctive central corkscrew structure surrounded by a delicate latticed spiral sheet
Whats the a common name for Scleractinia?
Brain coral
What Phylum are the genus Archimedes from?
Bryozoa
What Phylum is the Genus Prasopora a part of?
Bryozoa
What Class is the Genus Astraeospongia a part of?
Calcarea
Demosponges: Fresh or marine waters?
Can be found in both fresh and marine waters!
What geologic period are septastrea from?
Cenozoic (Miocene and Pliocene of the Tertiary)
What is the geologic age of fungia?
Cenozoic (Recent)
What Phlyum is the order Rugosa under?
Cnidaria
What Phylum is the Order Scleractinia part of?
Cnidaria
What Phylum is the Order Tabulata a part of?
Cnidaria
What Phlym and Order is the genus Hexagonaria part of?
Cnidaria (Phylum) and Rugosa (Order)
What Phylum and Order is the Genus Pachyphyllum a part of?
Cnidaria (Phylum) and Rugosa (Order)
What is the Phylum and Order of Favosites (Genus)?
Cnidaria (Phylum) and Tabulata (Order)
What Class do 95% of living sponges belong to today?
Demospongea
What Class is the Genus Astylospongia a part of?
Demospongea
What kind of spicules do Demosponges have?
Demosponges usually have organic spicules (spongin) but some also have siliceous spicules
What period is Hydnoceras an index fossil for?
Devonian
What Class is the Genus Hydnoceras a part of?
Hexactinellida
What are the characteristics of Hexagonaria?
Hexagonaria has a tightly packed colony of corallites and the corallites have a distinctive six-sided form (this is easier to see on a polished piece)
Is Hexagonaria a reef-builder?
Hexagonaria was a major reef-builder during the Devonian
What area is Hydnoceras found?
Hydnoceras is an easy-to-recognize New York fossil
What is the morphology of fungia?
It has a characteristic disc shape and large prominent septa that resemble a mushroom.
What area did Hexagonaria live?
It is a common colonial rugose coral with world-wide distribution
What's important to note about Prasopora?
It might look like an individual organisms bc of its gumdrop shape, but it really is a colonial organism. Note all the holes on the dome side
What Phylum is the Genus Astraeospongia a part of?
Porifera
What Phylum is the Genus Astylospongia a part of?
Porifera
What Phylum is the Genus Hydnoceras a part of?
Porifera
What area is Prasopora common to?
Prasopora is a common New York bryozoa
What form of Bryozoa is Prasopora?
Prasopora is a massive form of bryozoa. Massive forms are sometimes given the common name of "solid" or "stony" Bryozoan
Where was Receptaculites found?
Receptaculites was a part of the marine benthic epifauna
What are Rugose corals?
Rugose corals are common Paleozoic corals with a robust skeleton of calcium carbonate
Where do Rugose corals get their name?
Rugose corals get their name from the fact that the epithecal wall (outer wall) of the corallite (the skeleton created by an individual coral polyp) is wrinkled (rugose comes from the Latin word for wrinkled)
What order do all modern stony corals belong to?
Scleractinian order
What period is Astraeospongia an index fossil for?
Silurian
What period is Astylospongia an Index Fossil for?
Silurian
What kind of preservation usually happens to specimens?
Specimens are internal molds, the net-like surface pattern you see is an impression of the inside of the siliceous skeleton
What are sponges? How well are they preserved in the fossil record?
Sponges are simple multicellular animals that are not common as complete fossils. usually all that is found is an isolate spicule (the hard parts)
Where did the individual bryozoan animals (zooids) of the colony live?
The zooids lived in the tiny holes within the calcareous skeleton (not in the fenestrules) - see diagram A in Figure 14.21 on pg 344
What are the three main classes fossil sponges get grouped into? What is this classification based on?
There are hundreds of genera (thousands of species) of fossil sponges but most have traditionally been grouped into three classes based on spicule composition and form: Hexactinellida (glass sponges), Calcarea, and Demospongea
What are Scleractinia?
They are marine, benthic animals with skeletons of calcium carbonate (aragonite not calcite). There are about six hundred genera - some colonial and some solitary - and they come in many shapes (from massive lumps to delicate branches) and sizes. The colonial forms are found in shallow, tropical waters and form reefs. The solitary forms are found in a wider variety of habitats, including temperate and polar waters, and do not form reefs
Where can you find Septastrea?
common colonial scleractinian coral fossil of the east coast. colonies were large and branching and pieces are common
How do we compare scleractinian corals to tabulate and rugose corals?
The first scleractinian corals appeared after the tabulate and rugose corals of the Paleozoic and their origin is unclear. Although the scleractinian corals are younger than the rugose corals and tabulate corals, their skeletons, light and porous and made of aragonite, are less readily preserved so their fossil record is less complete
Are Tabulate corals colonial or solitary?
The tabulate corals were always colonial - there were no solitary forms
Where does the name Petoskey come from?
The town of Petoskey, Michigan located near the site of these interesting beach pebbles
Do Archaeocyathids have spicules?
They did not have spicules
When did fenestrate bryozoa live?
They lived in the mid-late Paleozoic and were quite common
What role did Archaeocyathids play?
They were small benthic epifaunal organisms but collectively formed extensive reefs
What happens when you wet Petoskey stones?
When dry, the pebbles look like rather ordinary rock, but when the pebbles are wet you can see the biological nature of the specimen, note the coral morphology
What's the common name for encrusting bryozoa?
bryozoa are commonly called moss animals and it is the encrusting forms where the common name seems most appropriate
What are the skeletons of Archaeocyathids made of?
calcium carbonate
What are their skeletons made out of?
calcium carbonate
What phylum and order are fungia (genus) a part of?
cnidaria (phylum) and scleractinia (order)
What phylum and order are the septastrea (genus) a part of?
cnidaria (phylum) and scleractinia (order)
Where did brain corals live?
colonial corals that thrive in warm, shallow, marine environments.
Describe Branching Bryozoa
come in a variety of shapes and sizes but are usually quite small and fragmentary
Morphology of Demosponges?
come in a variety of shapes and sizes; note the pores on the outer wall (called ostium) and the opening at the top (called the osculum).
Where do encrusting bryozoa form?
encrusting bryozoa form over shells, rocks, or other hard objects
How do we identify bryozoa?
even if only a small piece of bryozoa is found, the tiny holes in the skeleton of the calcium carbonate will allow the identification of the specimen as bryozoa
Where are favosites found?
found world-wide and is common here in New York
What is the common name for Hexactinellids?
glass sponges, because of their siliceous spicules
What are Brain Corals?
group of scleractinian corals (Family Faviidae) composed of many genera. They get their name from their spheroid shaped and grooved surface which resembles an animal brain
What is the morphology of Stromatoperoids?
horizontally layered structure with small vertical pillars, on the surface there are small bumps each with star-shaped pattern of canals that lead to a central pore (probably for water outflow), smaller pores, often not visible, across the surface were probably for water flow
what are solitiary rugose corals commonly called?
horn corals
What is the most distinctive characteristic of the tabulate corals?
how they got their name, the small horizontal dividers along the length of each corallite
What does Receptaculites indicate about the paleoenvironment?
indicates a warm, shallow marine environment of mid-Paleozoic age
what does Tabulae in latin mean?
little tables
Where do these solitary corals live?
live on a soft substrate rather than hard surfaces
What do many fossil Demosponges (like Astylospongia) have in common?
siliceous spicules
What kind of spicules do Class Hexactinellida sponges have?
siliceous spicules
What type of spicule is the most resistant and preserves the best?
siliceous spicules
What form is fungia?
solitary form
How big can brain corals get?
some brain corals can reach more than six feet in width
What can sponge spicules be composed of?
spicules can be composed of silica, calcium carbonate, or organic material (spongin)
What is the morphology of Archaeocyathids?
sponge-like fossils that lived in the Cambrian, they had cone-shaped, double-walled skeletons
Why are Scleractinian corals sometimes called hexacorals?
the addition of six septa at a time
What is the bottom of the corallite called?
the base
What is the top of the corallite called?
the calice
What is the calyx?
the calyx is where the coral animal lived, in the calyx you can see the very distinct radial septa (vertical walls)
What do the corallites of septastrea look like?
the corallites are prismatic and tightly packed. each corallite has six long septa that meet in the center of the corallite to form an axial structure. septastrea is a good example of why the scleractinian corals are called hexacorals
What is the morphology of Pachyphyllum?
the corallites in the corallum are not bounded by polygonal walls. Each corallite has a central conical elevation at the top of which is a crater-like pit
What is the corallum (colony structure) composed of?
the corallum is composed of prismatic corallites in contact with each other but separated by strong walls, the septa are clearly visible in each corallite
How are the easiest to recognize rugose corals identified?
the easiest rugose corals to recognized are the solitary varieties with their horn-shaped form. Note the epithecal (outer wall of the corallite) wrinkles and the distinct septa (vertical walls) that can be seen in the calice (the cup-shaped top of the corallite)
What is the skeleton of Archimedes made of?
the skeleton is made of calcium carbonate but the central axis is more robust and therefore preferentially preserved (See Diagram B in Figure 14.21 on pg 344)
Walls between corallites on favosites?
the walls between the corallites are thin but distinct and the tabulae are well developed, complete and numerous
What about Archaeocyathids resembled sponges?
they had pores in the skeletal walls and an opening at the top that resemble sponges
What do Archaeocyathids tell us about the paleoenvironment?
they indicate a shallow marine environment, warm water, normal salinity and Cambrian age rocks
What do stromatoperoid fossils indicate about the paleoenvironment?
they were one of the most important reef-builders in the shallow marine environment during the Paleozoic
What is the distinct morphology of Prasopora?
this genus have a distinctive hemispherical shape. The flat side faced down but was not attached to the bottom. The base is covered with concentric lines (and looks like a concretion). The top, convex side, faced up in the water column and the holes were the zooids lived can be seen with the magnifying lens
What is the morphology of Hydnoceras?
vase-shaped skeleton, prominent nodes, and a net-like surface pattern
How do individuals live in brain corals?
within the colony there are no walls between the individual animals as there are in most corals but the septa are distinct (note the plates perpendicular to the ridges)