User:Aezram/Dinonotes

General Stuff

• Small carnivorous bipeds evolved first because it's easier to digest meat
• Herbivorous theropods exist. They are called therizinosaurs
• Precocial Reproductive style: 'R' strategy, young born in large numbers, no parental care, high mortality rate
• Altricial Reproductive Style: 'K' strategy, young are cared for, Hadrosaurs, one specimen of Oviraptor on nest.

Ceratopsia

Ceratopsians ‘horned face’: All LC xcept Psitt. and Proto.. Well preserved, bone beds, N. Amer., herds, vegetarian browsers, intraspec combat. Frill for: sex, recognition, temperature, defense. Rostral bone, flared cheek bones (jugals, epijugals), dental batteries, coronoid process.

Psittacosaurus- Bipedal, MC. died soon, only cer. with gastroliths.

Neoceratopsia: Big heads, enlarged frills, keeled rostral bone (more beak-like), epijugal bone. Epijugal for muscle attachment? Incl.

Protoceratopsidae: no horns, short frills, coronoid process with muscle thru fenestra. Protoceratops: Numerous, Asian deserts. mid late-pre late C.

Ceratopsidae: very prominent frill, facial horns, huge nostril, dental battery, hooves on toes subdiv into:

Centrosaurinae: short or no post-orb horns, short frill, rounded epoccipitals. Centrosaurus

Chasmosauridae: long post-orb horns, long frill, triangular epoccipitals. Triceratops, Pentaceratops. North American.

Ornithopoda

Ornithopoda: ‘bird foot’: EJ-LC. split into Heterodonts and Euornithopods. Ventrally offset pmax, occluding molars, long jaw joint.

Heterodontosauridae: (mixed teeth, tusk in front, batteries in back) EJ-MJ complex teeth, shorter necks, longer tails, bipeds,

Euornithopoda: (true ornithopods) LJ-LC Pleurokinetic skulls. subdiv into:

Iguanodontoidia: LJ-LC everted pmax, broad snout, toothless beak, thumb spikes, ossified tendons, broad hooved feet, facultative quadrapeds.

Hadrosauridae: duck-billed, 3+ teeth per tooth position, coronoid process, no thumb. ate varied plans, no gastroliths, weak jaw joints, mummies.

Lambeosaurinae: hollow crested, did stuff with em.

Saurischa

Saurischia: ‘lizard hip’ Monophyletic groupd defined as all Dinosauria closer to Allosaurus than to Stegosaurus. Has (among other things) twisted and enlarged thumb, relatively longer neck, pelvic modifications. Eoraptor and Herrerasauridae are more basal members of Saurischia.

Sauropodomorpha

Sauropodomorpha: ‘lizard-foot-shape’: -messy clades due to lack of big fossils, peg shaped teeth, ten or more cervical vertebrae, small skulls, extra tail vertebrae, big ass thumb with spike.

Prosauropoda: LT-EJ early sauropods. smaller, and bipedal. defined by a twisted thumb, elongated back vert., skull mods. Thecodontosaurus

Sauropoda: most defining characteristic is size, since all others changes are made to support the size. smallest is still 20 ft long,.

Eusauropoda

Brachiosauridae 50 ft rise. vaulted skull, distinctive snout,13 elongate cerv vert., long forelimbs, non-bifur. cerv. vert., vertically oriented neck.

Titanosauridae 30 ft long. all titanosaurs have osteoderms. robust radius and ulna. Alamosaurus

Diplodocids long and narrow skull, peg teeth, horizontally oriented neck. 80 tail vert. Apatosaurus, Diploddocus, Seismosaurus, Supersaurus

Evidence for tail-cracking Stiffened and strengthened base. Proper taper. Thin caudal vertebrae.

Evidence against No poppers. Fragile bones will break at great speed if hit.

Problems with being BIG 1. Structural stability. Solid limb bones and large muscles required. (Mass increases as the cube of length, strength as the square) 2. Nutrition. Food supply dependent on migration. hundreds of gastroliths.

Jurassic Sauropod Gap gap in fossil record, no sauropods, then a few again in the Cretaceous. Explanation: not everything gets fossilized.

Theropoda

Theropoda ‘beast foot’ -messy clades, likely to change. -derived characteristics: extreme hollowing of long bones, large hands, vestigial 4th 5th digits.

Ceratosauria

Tetanurae MJ-present -back half of tail stiffened by interlocking zygapophyses., antorbital modification. A big clade of theropods that contains spinosauridae (basal) and avetheropoda (more derived)

Avetheropoda This clade splits into carnosauria and coelurosauria. Maxillar fenestra.

Carnosauria Monophyletic group that contains Allosaurus et al. Larger nostrils, sinuses, and braincase.

Coelurosauria Closer to the birds, this clade shares these derived features: enlargement of antorbital fenestra, narrow contact between pubis and ischium (becoming more bird-like). This clade contains Tyrannosauroidea, Maniraptiformes

Maniraptores Maniraptors include the clades oviraptorsauria the toothless egg-suckers, and therizinosauroidea the weird apparently herbivorous.

Eumaniraptora Closer yet to the birds, this clade contains deinonychosauria (velociraptors) and avialae

Avialae

Avialae ‘bird-like'

Archaeopteryx: Jurassic, 150mya. 7 specimens, 1 feather found in Germany. Birdlike features: expanded braincase, asymmetric feathers, keeled sternum, 3 and 1 foot. Could fly, but not well. Unbirdlike features: teeth, three fingered hand with claws, long stiff tail, raptor-like saurischian pelvis.

Rahonavis: bit bigger than Archaeopteryx with enlarged sicle claw on feet, six fused sacral verts

Pyrgostylia: shortened tail, reinfoced shoulder (elongated coracoid bones)

Ornithothoraces 'bird chest': fusing of digits into carpometacarpus (chicken wing), evolution of atula "bastard wing"

Enantiornithes 'opposite bird': Worldwide distribution. Like birds: sparrow-sized, keeled sternum, slim furcula (wishbone), partially fused carpometacarpus, modern-bird like wrist, perching foot. Unlike birds: gastralia (belly ribs), numerous back vertebrae, unfused pelvis.

Ornithuromorpha: Features: pubis parallel to ilium and ischium, reduction of trunk vertebrae, smaller acetabulum.

Hesperornithiforms: large, long-necked, flightless, diving birds with big feet. Teeth. (Enaliornis EC, England.)

Ichthyornithiformes: long necked toothed gull-like, flying, massive keeled sternum (Ichthyornis LC, N.America)

Aves: All LC and later. Encompasses screamers and waterfowl (Anseriformes, loons (gaviiformes), and possibly shorebirds such as pipers, gulls, and auks (charadriiformes), landfowl (galliformes), petrels (procellariiformes), parrots (psittaciformes). Includes modern birds. Includes hoatzin modern bird with three claws.

Other Bird Info

Contraversial first bird: Protoavis: 225mya, Triassic.

Defining characteristics of birds: feathers, endotherms, 4-chambered heart, expanded skulls with huge orbits, large brains, toothlessness (modern birds), carpometacarpus, shoulder joint, rigid pneumatic skeleton, furcula, keeled sternum, 3 and 1 feet, bladderless.

Evidence that Birds are dinosaurs: perforate acetabulum (Dinosauria), opisthopubic pelvis (Dromaeosauridae), thin-walled hollow bones (Theropoda), ornithoid-style eggshell (Theropoda), expanded braincase with kinetic skull (Theropoda), wishbone (many Theropoda), juvenile three-fingered hand (in Hoatzin) (Theropoda), rigid tails, semilunate carpal (Coelurosauria), feathers (Coelurosauria), enlarged second toe claw (Dromaeosauridae), hand-arm structure (Dromaeosauridae)

Arguments that Birds aren't dinos (hooey): 1) Dinos with feathers are really flightless birds that evolved dino characteristics 2) First true feathers appear on non-dinosaurian archosaur longisquama 3) first true bird (protoavis) appeared in LT 3) Archaeopteryx appears in LJ whearas their supposed ancestor dromaeosaurids don't appear until Cretaceous

Feathered dinosaurs from early Cretaceous in China: Sinosauropteryx, Caudipteryx, Microraptor, etc.

Remiges: flight feathers, Retrices: tail feathers

Metabolism

Endotherms: generate body heat internally, generally more active and take more energy to upkeep

Ectotherms: recieve most or all of their bodyheat externally, (many grow thorughout their whole life [is this true?])

Homeotherms: internal temperature fairly consistant

Poikilothermy/Heterothermy: fluctuating internal temperatures

• Most endotherms are endothermic homeotherms. Exceptions: hummingbirds, hibernating polar bears
• Most ectotherms are poikilotherms.
• Ectotherms are not inferior to Endotherms
• Coelurosauria at least was probably endothermic.

Thermoregulatory strategies: behavioral strategies (burrowing, shivering, panting, building hives and houses), insulation, geography, efficient resperation, evaporative cooling.

Other Mesozoic Animals

Flying ones:

Pterosauria: includes rhamphorhyncoidia and pterodactyloidea

Rhamphorhyncoidia: Triassic to Cretaceous, < 2m, long tail, short head, no crest

Pterodactyloidea: Jurassic to Cretaceous, < 15m, short tail, keeled sternum, some have crests

Marine ones:

Ichthyosaurs: Early Triassic to Early Cretaceous, fully marine, euryapsids, dolphinny, usually 1-3m, one Triassic one reached 15m

Plesiosaurs: Early Jurassic to Late Cretaceous, amphibious, euryapsids, two kinds: elasmosaurids (long necked ones), pliosaurids (large headed ones), sea-monstery

Mosasaurs: Late Cretaceous, diapsids, fully marine, lizardy

Mammals: Mammals form four main families: eucynodonts (become most modern mammals), monotremes (platypus and echidna), marsupials, and multituberculates (survive KT but die anyway). Mammals remain small, nocturnal, and sneaky until they fill ecological niches left by dead dinos. Mammals began evolving 220 mya in the Triassic. A recent find in the Lianong province shows that larger, dog-sized mammals may have competed with dinos as predators. Repenomamus was found with a psitticosaur in its belly.

Extinction

Three plausible extinction hyptotheses: Climate change (sea level movement), Volcanism, and Asteroid

Common dinos at time of extinction: Tyran., Ornithomimidae, Dromaeosauridae, Titanosauridae, Nodosauridae, Ankylo., Hypsilophodontidae, Hadro., Pachy., Protoceratopsidae, Ceratopsidae

Marine pattern of extinction: detritus feeders prevailed over filter feeders. Terrestrial pattern: Aquatic forms prevail over land forms

Ferns survived K-T better than other plands, forimenifera (little sea things) got smaller, K-T extinction was a rapid (according to Hilde) death-thing.

It was not the worst mass-extinction ever, that honor belongs to the permo-triassic "great dying"

The late Cretaceous was full of active plate mvmnt, mountain-makin', and volcanism.

Between 65-60 mya the Deccan traps in India covered 500,000 km^2 with magma.

The sea levels decreased in the Cretaceous, with more of the continental land mass being exposed than in the last 60 mya.

Effects of the asteroid impact: 1) Spontaneous death due to squashing. 2) Rain of fire and debris. (up to 400 F) 3) Drowning (tsunamis) 4) Noxious fumes (hit a sulfur deposit) 5) Rapid cooling and dust clouds.

Evidence for Asteroid: Iridium anomalies, ejecta layer, soot (fireball layer), shocked quartz, asteroid fragments, tempestites (Tsunami deposits), impact crater (Chicxulub)

Discoveries

• The iridium anomaly at the K-T boundary was found based on deposits from Gubbio, Italy.
• The research team from Cal who worked on it were named Alvarez, Alvarez, Asaro and Michel.
• Aside from iridium spikes, shocked quartz (deformed by intense pressure) is a line of evidence for impact.
• The "Smoking Gun" is the crater itself. Glen Penfield found a 180 km diamater crater in Chicxulub in the Yucatan.

Ghost Ranch Coelophysis Quarry

New Mexico, in sedimentary rock, Late Triassic. Flooding explains orientation of skeletons (preferential alignment), but not number of carnivores gathered in one place. Not a tar pit because of high degree of articulation. Hilde's theory: a drought caused fighting for water, then corpse transport by flood waters.

Californian Dinosaurs

No Triassic Dinos. Few in Jurassic. All Cretaceous. One trackway site in CA (the Mojave, early Jurassic). 26 dino sites. Most CA dinos are Hadrosaurs.

LC Dinos: Aletopelta (ankylosaur), Saurolophus.

Allan Bennison (1936): First dino finds in California: Saurolophus

Pterosaurs and Marine reptiles like elasmosaurs, icthyosaurs, and mosasaurs were here.