Dinosaurs Exam II

Ornithomimosauridae

"Bird mimic lizards." They had no teeth with horned beaks and fused metatarsal in feet. They resemble large flightless birds. They have small heads long necks and legs, lightly built skeletons, large eyes, and flexible neck joints for mobility. Extremely fast, ran with chest horizontal. Feathers.

Hadrosauridae

"Bulky reptile." Refers to whole group of duck billed dinosaurs. 7-10 meters long. Spanned middle cretaceous to end of the cretaceous. They had dental batteries, cemented teeth, grinding surface, and replacement teeth beneath. No thumbs and three toes in the hindlimb. Diversity in head crests. Females lest rigid crest. Males more rigid crest. Juveniles vs. Adults. Most likely used in vocalization.

Heterodontosauridae

"Different tooth reptile." They had differentiated teeth and tusks. However, this was only a male trait. They had a low hinge position of the jaw. Bipedal with ossified tendons along back vertebrae. They were small, 1 - 1.5 meters.

Oviraptoridae

"Egg thief lizard." Toothless jaws, short snouts, 2m long, large claws on hands and slender hind-limbs. Durophageous Skull (thickened) for shell crushing. Discovered sitting on eggs (advanced behavior).

Protocertopsidae

"First Horned Face." Had a large head, broad frills, pointed keel, evolved into obligatory quadrupeds. Generally smaller and more primitive than other ceratopsids.

Anklosauria

"Fused Reptiles." One of the most successful ornithischian dinosaurs. Body covered with osteoderms which formed rings around the neck, and fused together on back to make large shield. Armored eye lids. Also obligatory quadrupeds. Leaf shaped, non-interlocking teeth. Grinded food in their mouth by wear on teeth. Complex nasal passage. Wide armored heads w/ horns at posterior corners. Tail Club. Would not fight, they turtled. Club as a weapon.

Coelurosaurs

"Hollow tailed lizards."

Ceratosaurs

"Horned lizards."

Iguanodontidae

"Iguana tooth." One of the first dinosaurs discovered and one of the well known dinosaurs. Broad, toothless beak, with 100s of leaf shaped teeth in the back of the mouth. Dental battery. Horse like snout. Three toes on the hindlimb, long sturdy limbs for quadrupedal walking. Massive hind-limbs. Up to 10 meters long. They had sliding jaws and thumb spikes on the first digit. The 5th digit was offset. Central 3 digits ended in hove like structure. Only advanced ornithscians showed true chewing movement. Upper jaw sliding up and down and sideways. Herd animals by trackways.

Carnosaurs

"Meat lizards."

Psittacosaurus

"Parrot Dinosaur." Primitive marginocephalian that was bipedal. 2 Meters in length. Forelimbs: - Three functional toes. Hindlimbs: - Four slender toes. Had a cheek teeth battery, high nostrils, flaring cheeks, and rudimentary frill.

Stegosauria

"Plated Reptiles." Small, long and pointy heads. Short, stout forelimbs. Long hind-limbs gave them arch shaped back. Hooves. Vertical bony plates and spines. Single or double row along the neck, back and tail. Sometimes covered hips and legs. Toothless beak or leaf-shaped teeth. Brain size small, dumbest dinosaur? Extinct for 80Ma before the end of the Cretaceous.

Dromaeosauridae

"Running reptile." Numerous teeth serrated on both edges, long forelimbs with elongated 3 fingered hands. Tail with ossified tendons. Hind foot with enormous retractable claw on second digit. Example: Velociraptor; tail stiffened for counterbalance.

Thyreophora

"Shield bearers." Dermal bone armor plates. Armor plates called scutes or osteoderms, 'float in the skin.' Covered in living tissue, keratin does not have nerves or blood vessel. Didn't have speed so they needed armor, but it weighed them down. Forced obligatory quadrupeds. Forelimbs significantly shorter than hind limbs. Forced to eat low vegetation.

Cretaceous Period

"The Chalk" White Cliffs. K/T or K/Paleogene Boundary: 65ma.

Pachyrhinosaurinae

"Thick nosed lizard." Large nasal horn on the snout and short head frills.

Troodontidae

"Wounding tooth." Largest brain-body ratio of any dinosaur, binocular vision and large eyes, long skull with narrow snout, agile, 2m high, possibly warm blooded, covered with feathers. Named after single narrow tooth.

Series of Events of Impactor

1. 6-10Km strikes earth. 2. Dust and vapor clouds block out sun and disrupts photosynthesis and food chain. 3. Molten ejecta Outwards of 2500km. 4. Lead to 20 million years of rapid diversification.

Evidence for Impact

1. K/T Iridium spike in clay layers. 2. Shocked Quartz 3. Glass Spherules

Tyrannosauridae: Scavenger or Predator?

1. Scavenger arguments: - Small eyes. - Functionless forearms? 2. Predator arguments: - Forearms for slashing. - No large animals survive by scavenging. - Huge claws. - Muscular. - Large head taking over the grasping function.

In a undisturbed sequence of sedimentary rocks, younger layers overlay older layers, according to the principle of: A. (E3) Superposition B. (E3) Original continuity C. (E3) Original horizontality D. (E3) Uniformitarianism

A

The Cambrian period is a time in Earth history when: A. (E4) The first abundant shelly organisms appear in the fossil record B. (E4) Earth's interior was so hot that a solid outer crust, if present, was likely being extensively remelted C. (E4) Stable continental interiors, termed cratons, first formed D. (E4) The dinosaurs appeared and came to dominate large-scale terrestrial life

A

Spinosaurds

A sub section of theropods in the tetanurae group. They had longer snouts than other theropods with large and extremely strong forelimbs. The 'Megaraptor.' Possibly in the carnosauria infraorder with neural spines (sail backs).

Fully Erect Posture

Acetabulum, straight ankle hinge, long lower limb.

Deccan Traps

An outpouring of CO2 caused the killing of the dinosaurs. Outpouring of dust. Flood Basalts as evidence.

Infraorder Coelurosauria

Ancestors of birds with long slender hands, long digits (2 and 3), long necks and forelimbs, stiff hollow tails. The first group to evolve feathers. Arctometatarsalian foot.

Earth is approximately how old? A. (F1) 15 billion years B. (F1) 4.57 billion years C. (F1) 40 million years D. (F1) 6000 years

B

We can observe Evolution occurring within our lifetime; therefore Evolution is considered only a theory. A. (F2) True B. (F2) False

B

Ornithischian Pelvis (Bird Hip)

Backward facing pubis.

Shocked Quartz

Bohr found that there were shocked minerals from bass river spherule layer.

Chixilub Crater

Chixilub, Mexico has large deposits of tektites and iridium anomalies. Proof in the outer rings. Hildebrandt 'andesite' and cenotes. Crater 85km wide caused by 10km meteor. Three peak rings: - Peak Ring: 85km - Inner Ring: 130km - Outer Ring: 195km Gravity Complex

An iridium-rich layer of clay, glass spherules, and shocked quartz grains strongly suggest that the K-T boundary extinctions were at least in part caused by ______________. A. (F5) a long trend of global warming B. (F5) a long trend of global cooling C. (F5) worldwide explosive volcanism D. (F5) the impact of a bolide (meteoroid or comet)

D

Dinosaurs first appeared during the ________________ period. A. (E5) Cambrian B. (E5) Devonian C. (E5) Permian D. (E5) Triassic

D

Evidence for a united Pangaea comes from the fossil record of which type(s) of organisms? A. (F4) Plants B. (F4) Large terrestrial animals C. (F4) Freshwater animals D. (F4) All of the above

D

The first mammals appeared during the ______________ period. A. (E2) Cambrian B. (E2) Devonian C. (E2) Permian D. (E2) Triassic

D

Wegener proposed continental drift after he observed evidence from fossils, glacial deposits, and the fit of the continents that suggested that all continents were once: A. Aligned north to south along the prime meridian during the late Cenozoic. B. Aligned east to west along the equator during the late Mesozoic through the Cenozoic. C. Combined to form a supercontinent (he termed Rodinia) in the Proterozoic. D. Combined to form a supercontinent (he termed Pangaea) in the late Paleozoic through the Mesozoic.

D

Ornithopods

Dinosaur fauna with Bird-like pelvis, predentary skull bone, and ossified tendons along vertebral column. The bipedal ornithischians. Ornithopods differentiated by its mouth. They have a premaxillia bone that over hangs the maxilla bone. Both are on the upper jaw.

End T Mass Extinction

Dinosaurs become dominant life form. Volcanism event in the Central Atlantic magmatic Province. Maybe an impact. Methane hydrate release. Most marine reptiles, protomammals, and archosaurs are gone except for ichthyosaurs, plesiosaurs, crocodilians, pterosaurs, and dinos.

Dinodiversity

Due to tectonic movement of continents, warm climate and high oxygen levels. Iguanodon was the main herbivore in many areas. (NA, Europe, and Asia). Last of the stegosaurs in Laurasia and first of the marginocephaliains in Laurasia and Asia. Sauropods in Southern Godwana. Feather Theropods in Asia, NA, and Europe.

Age of Browsers (Jurassic)

During the Jurassic period, vegetation was processed in the stomach with gizzards. No flowering plants.

Prosauropods

Early plant-eating dinosaurs that are either ancestors to the sauropods or evolved with them. Spanned late triassic to early jurassic. Debated wether they were quadrupedal, bipedal, or both. Riojasaurus - 11m Heavy Built Skeleton Plateosaurus - 6-8m Mussaurus - 20cm

Triassic Period (250Ma-199Ma)

Events: 1. Dinosaurs first appear. 2. Mammals, turtles, frogs, crocodiles appear in early forms. 3. Pterosaurs and Marine reptiles appear. 4. Birth of Atlantic Ocean. 5. Started with P-T extinction. Pangea formed with all continents (237). Climate was hot and dry which explains why reptiles and dinosaurs became dominant and not mammals. Life was similar everywhere on Earth because all land was attached. Differences in climate, such as monsoon wet and dry seasons. Vegetation: - Gymnosperms (cones or pollen spores). - Ferns, Woody plants (ginkgo trees, cycads, pines, cypresses, redwoods). Many reptilian sprawlers and quadrupeds. Other vertebrates such as labyrinthodonts, thecodonts, and archosaurs. Frogs, turtles, pterosaurs, and mammals. Ichthyosaurs and Tanystropheus, some plesiosaurs. Break up of Pangea at the end of the triassic period 210ma. Formation of Proto-Atlantic.

Fully erect posture is a trait found in ALL dinosaurs, reptiles, birds, and mammals. A. (E1) False B. (E1) True

False

Cetiosauridae

Family of Sauropods that has traditionally been a 'waste bin taxon' of various unrelated species.

Tetrapod Limb Morphology

Forelimb: Upper Limb -Humerus Radius Ulna Carpals Metacarpals Manus Digits (Phalanges) Hindlimb: Upper Limbs- Femur Tibia Fibula Tarsals Metatarsals Pes Digits (Phalanges) Ilium Acetabulum (Femur Ball) Pubis Ischium Ilium (Up Top)

Saurischian Pelvis (Lizard Hip)

Forward facing pubis.

Ceratosauria

Four fingers on hand with lightened skulls with bumps and crests meant for social display. Fused hindlimb and pelvic girdle bones.

Dinosaurs have all have...

Fully-Erect Posture & Elongated Pubis and Ischium.

Sauropod Behaviors

Gizzard stones, possibly gigantotherms, obligatory quadrupeds, might have fed horizontally. Trackways indicate that they traveled in packs.

Ceratopsidae

Had facial horns and very large skulls. Includes: - Subfamily Pachyrhinosaurinae. - Subfamily Ceratopsinae. They were heavy built with a deep rib cage, a fused backbone and hip, and they were quadrupedal. Elaborate frills and large nostrils. Function of frills horns: Defense, heavy muscles anchored for chewing. Display. Length and color of head frills different between males and females.

Ceratopsia

Had parrot beaks (ie: pointed rostral and predentary bones). Only this group has rostral bones. Small to large body sizes of 1-8 meters long.

Lambeosaurines

Have hollow crests.

Alvarez Team

Helen Michel, Frank Asaro, and Walter/Luis Alvarez coined the idea that the K/T extinction was a result of an extraterrestrial cause. Gradualism.

Titanosauridae

Huge armored sauropods up to 18m with low long snout, well spaced teeth, and nostrils high on forehead. The biggest sauropods and most diversified.

Glass Spherules

Identified altered micro-tektites (spherules).

Primitive Ornithopods

Include: - Heterodontosaurus - Hypsilophodont. Had cheeks, were fairly small bipedal and fast runners. Spanned the early jurassic to the end of the cretaceous.

Age of Grazers (Cretaceous)

Introduce dental battery structures and angiosperms. Little to no niche-stratification.

Nodosauridae

Lacked horns at skull corners and no armor on skull, no tail club.

Unaffected Families in the K/T Extinction

Land plants, crocodiles, birds, lizards, snakes, turtles, 25% of Marsupials.

Ceratopsinae

Large brow horns over the eyes with long head frills. Triceratops: 'three-horned face.'

Theropod Morphology

Large, curved, laterally compressed, and serrated teeth with an Intermanibular joint. Mobile next joint. Single fused collar bone. Three digits, one offset for possible grasping. Grasping hands with long clawed hands. Large orbits or eye sockets, with an extra antiorbital fenestra and large brains. Some feathered. Obligatory bipedal with tail either flexible and close to the body or rigid and distal to the body. Hollow bones.

Dinosaurs First Appearance

Late Triassic.

Theropod Feet

Look more bird like, but they are called beast or mammal foot.

Ornithopod Feet

Look more mammal-like, but they are called bird feet.

Allosauridae

Lots of holes in the skull with crest or bumps on the skull. Found near sauropods, so they probably hunted them.

Homalocephalidae

Low skull domes.

End Cretaceous Mass Extinction

Mammals become dominant life form.

Jurassic Period (199Ma-145Ma)

Marine reptiles, pterosaurs, mammals and dinos continued to flourish, while other large carnivores and herbivores are gone. Coelophysoids, Prosauropods, and primitive Ornithischians die out; they were replaced by more specialized dinosaurs. "The Golden Age of the Dinosaur World." Terrestrial Animals: Medium to small sized sauropods. Small stegosaurids. Primitive tetanurae show up (fused tail lizards). First beaked dinos (hypsilophodontidae) and primitive thyreophorans. Large and small predators as well as armored stegosaurs and ankylosaurs. More advanced ornithopods. Large sauropods and stegosaurids. Marine Life: Large plesiosaurs. Reef builders, ichthyosaurs, squid, primitive sharks. Geography: - Still a super continent. - Animals similar throughout world. - Dinos begin to change by mid-jurassic. - Epicontinental Seas form late and different environments form. - Rising seas levels. - Morrison formation from rocky mountain weathering and sand deposits on the side of mountains. (Good fossil preservation). - Now lake, stream and swamp deposits. - Most diverse dino deposit. Climate: - Warmer and Wetter. Vegetation: "Age of Cycads." Most abundant late jurassic dinos: Carnosaurs, Stegosaurs, and Sauropods.

Theropods

Meat eating predators that spanned the entire duration of the dinosaurs ranging in size from chicken to T-rex. Named after beast foot.

Pachycephalosauridae

Medium to large body sizes. 2-10 meters long. Thickened skull roof of solid bone. High skull dome. Low skull domes cold represent juveniles of dome headed adults. Bipedal locomotion with forelimbs shorter than hindlimbs. Possible head butting to predators, threats and other pachys. Vertebral articulations provided spinal rigidity and suggest thats pachys could make their whole body horizontal to transmit stress during ramming. Round shape would lessen the blow. Domes could work as a possible species recognition.

Diplodocidae

Named after 'double beam' and chevron bones. They have long slender skulls and muzzles. Peg-like only in front of the mouth with nasal openings at the top of the skull. Longest bodies. Short ribs. Possibly fused vertebrae in the tail. Brontosaurus, or Apatosaurus.

Group Tetanurae

Named after the fused tail lizards. Three digits on hand (1-2-3 present) and (4-5) lost on forelimb. Large hands and fused tails. Teeth in front of orbit with extra antiorbital fenestra.

Cleft Neural Arch

Neural spine is bifurcated with strong ligament to support head.

Cretaceous Period (145Ma-65Ma)

New plants, new plant eaters. Little animals would be familiars, salamander, turtles, snakes and lizards. Modern type mammals evolve. First appearance of placental and marsupial mammals. Other vertebrates, primitive egg laying mammals. Rudist (bivalves and clams) reef builders. First appearance of modern sharks, and turtles. Ankylosauridae and Ceratopsians. Little stegosaurs and sauropods. Iguanodontidae, Psittacosaurs, ankylo and nodosauria. Tryannosauridae, Coelosauridae and Hadroosauridae. Heyday of Crocodilians. huge lake and marine crocodiles up to 33 feet along. Top marine predators with plesiosaurs. Heyday of Pterodactyls. 40 ft wingspan Geography: - Movement of continents and rise and fall of sea level led to parts of earth becoming isolated. - Dinos begin to evolve differently. - Sea level very high. Climate: - "Greenhouse World." - Tropical temperatures extend towards poles. It was the warmest period in the 150Ma. Vegetation: - Angiosperms (Flowering Plants). - Small weedy plants to large flowers and grasses. - Magnolias, walnuts, and laurels.

Sprawling Posture

No acetabulum, bent ankle hinge, small lower limb bone.

Herrerasauridae

Oldest known and one of the 1st dinosaurs that are closely related to theropods and small to medium carnivores. Saurischian Pelvis, five fingers, claws, short forearms, and fast runners.

Brachiosauridae

One of the heaviest land animals that were extremely tall and the forelimbs are longer than the hindlimb. 13 neck vertebrae and 50 tail vertebrae.

Sauropods

One of the most successful groups of herbivore dinosaurs that span the entire age of the dinosaurs (T-K). Largest land animals of all time with small heads, spatulate teeth, short feet, at least 10 elongated vertebrae in the neck, and large claws on the 1st digit of forefeet. Likely didn't have trunks.

Ornithischians

Ornithopoda, Thyreophora & Marginocephalia.

Dinosaur Ecosystem Structure (Cretaceous)

Predators were highly specialized. Dental apparatus and hand structures.

Dinosaur Ecosystem Structure (Jurassic)

Predators were unspecialized. Small and large predators.

Theropod Behavior

Ran w/ body extended forward. Scavengers teeth were not worn, predators had bite marks on their skeletons. Hunted in packs to hunt large prey. Ambush style hunting, running down prey.

P-T Mass extinction.

Reptiles become dominant life form. Massive eruption of lava from Siberia and emission of CO2 causes dramatic climate change and ocean anoxia. With possible impact? Archosaurs and plants survive, land was barren after event.

Ornithopod Behavior

Sat on their eggs and nested together. Diverse environments and might have swam to avoid predators.

Saurischians

Sauropodomorpha & Theropoda.

Carnosauria

Short necks and forelimbs with heavy frame skeletons.

Camarasauridae

Short, heavy skulls with blunt muzzles, chisel like teeth, and nasal openings in front of the eyes. Solid built skeletons, 12 neck vertebrae, longer forelimbs, and flat back.

Dinosaur Ecosystem Structure (Triassic)

Small bodied thyreophora, prosauropods. Meat and plant eaters.

Hypsilophodontidae

Small dinosaurs with light skulls, jawbones that move slightly outward to help chew, very stiff tails allowed for fast running and cheek teeth blades.

Gastric Mill Gizzard

Small stones in the stomach region that helped digestion.

Hadrosaurines

Solid crests or none at all.

Infraorder Carnosauria

Some of the largest meat eaters ever at 5m or more in size, large heads, short powerful necks, short forearms, massive hind limbs, and long tails.

Marginocephalia

Spanned the late jurassic to the late cretaceous period.

Dinosaurs are ________ Archosaurs.

Specialized. Three + Sacral Vertebrae. Shoulder joint backwards. Modified hand. Expanded Ilium.

Archosaurs Postural Behavior

Sprawling, Semi-Erect, Fully-Erect.

Advanced Mesotarsal

Straight hinge path and swinging motion in upright position.

Infraorder Maniraptora

Swivel wrists (curved metacarpal 3 and semilunate carpals).

Thagomizer

Tail spikes attached to side and faced outward. No more than two pairs of spikes. Thagomizers show damage indicating that the Stegosaurus used them for active, rather than passive defense.

Fabrosauridae

The first of the the ornithischian dinosaurs that lived in the early jurassic. They were very small herbivores.

Dinosaur Diversity and Extinction Rates

The more diverse the dinosaurs, the less sudden their extinction.

Arctometatarsalian Foot

The wedging of metatarsal 3 between 2 and 4.

Plate Functions

Thermoregulation, social display.

Pachycephalosauria

Thick headed reptiles with a thickened skull roof.

Tyrannosauridae

Two fingers on the hand (digits 1 and 2 only on forelimb). They had very small forelimbs with unknown function. Up to 14m in length with massive heads and short necks. Massive pelvis and pillar like hind-limbs. Long heavy tails. Possible scavengers. Early descendants had protofeathers.

Niche Stratification

Verticality of plant eating. - High browsers (Sauropods) ate 5 to 20 m high. - Medium browsers (Stegosaurs) ate 3 to 5 m high. - Low browsers (Ornithopods) ate 0 to 3 m high.