Be aware of the geologic time scale (periods of Mesozoic, timing of this era& the periods, major eventsShort hand:Paleozoic Era – 540-250 mya-Permian Period – 300-250 mya Permo-Triassic ExtinctionsMesozoic Era - age of the reptiles-Triassic Pd – 65 mya-Jurassic Pd – 205-145 mya Age of the DinosaursCretaceous Pd – 145-65 mya * Age of the Dinosaurs*Cenozoic Era – 65 mya – presentElaboration/Major events:Late Permian – 255 mya-pangea; mountain building (rockies & Appalachians pushed up)Worldwide glaciation & mass extinctions = Permo-triassic crisis ->-End of Permian: greatest extinction ever 99% of life diedEarly Triassic – 237 mya-continuation of extinctions & glaciations, BUT entering warming period-*age of dinosaurs* & life diversifying post permo-triassic extinction-Breaking up of Pangea-Low atmospheric oxygen levelsLate Jurassic – 152 mya-ongoing pangea breakup throughout period-by late Jurassic Central Atlantic ocean separating africa from E north Am. & E gondwana begun to separate from W gondwanaLate Cretaceous – 94 mya-South Atlantic fully open-higher sea level due to – new rifts in ocean basin-India seperates from Madagascar, moving N toward Eurasia-N America & EU connected; Australia & antartica connected-very warm climate-lots of warm water movement warming the polar regions-No ice caps-Dinosaurs & palm trees in far N & far SK/T Boundary 66 mya-Extensive mountain building (2nd push up of rockies)-inland seas drying up-flowering plant radiation & 2nd insect radiation-General blossoming of life (mammals just taking off) BUT THEN! An asteroid impact!!!-massive extinctions from – dust cloud darkening of earthGeologic Time scale – biological evolutionPaleozoic Era – 540-250 mya-Permian Period – 300-250 mya *Archosauria originated-Carboniferous pd – *Amniotes 1st appeared*Diapsida evolved-Devonian pd*Sarcopterygians first appeared - present-Silurian pd-Ordovician pd – -Cambrian pd - Mesozoic Era –*Archosauria took of* Dinosaurs-Triassic Pd – 65 mya*Crocodilia 1st arose-Jurassic Pd – 205-145 mya Cretaceous Pd – 145-65 mya *dinosaur 2 independent radiations due to continental movements*Crocodilia diverse*Coelurosaurs*dromeosaurs (late)*Microraptor gui*archaeopteryx*jehalornis prima – short round feathers, teeth*confuciousornis ***pygostyle toothless (convergent)*Iberomesornis ****strut like coracoid, pygostyle & reduced foot claws (bird morphology traits)Neognathes: Galliformes & anseriformes evolution beganCenozoic Era – 65 mya – presentBe aware of major groups of Craniata (craniata, vertebrata, gnathostomata, osteichthyes, sarcopterygii, tetrapoda, amniota, sauropsida, diapsida, archosauria)Phylogenic tree1.craniata - Myxinoides (hagfishes) & Vertebrata2.vertebrata - Petromyzontidea (lampreys) & Gnathostomata3. gnathostomata - Chondrichthyes (sharks, skates rays) & Osteichthyes4. osteichthyes – actinopterygii(ray-finned) & sarcopterygii (lobe finned fish)5. sarcopterygii - Actinistia (coelacanths) & Rhipidistia6. rhipidistia (non important) - dipnoi & tetrapoda7. tetrapoda - Lissamphibia & amniota10. amniota - Sauropsida & synapsida Sauropsida - Diapsida & Testudinia (turtles) Diapsida - Lepidosaurs & ArchosauriaArchosauria - Crocodilia & Aves Synapsida (mammals)Sarcopterygii - Early devonian to present-dermal (form of skin) & endochondral (forms in cartilage) bones-lobed finned fishes (Includes Tetrapods)Tetrapoda - (within sarcop)-Pectoral girdle separate from shell-zygopophyses on vertebrae-limbs w/ carpals, tarsals & units-pelvic girdle attached to vertebral columnNOTE: -Tetrapods contain stem tetrapods(extinct) and crown group tetrapods--Crown group tetrapods contain batrachomorphs & reptilomorphs----Batrachomorphs – stem tetrapods, lissamphibia----Reptilomorphs – amniotes-----Amniotes – synapsids (mammals & mammal like reptiles), parareptiles(turtles) & eureptiles------Eureptiles – stem eureptiles (extinct) & Diapsids-------Diapsids – Lepidosaurs, turtles(?), & archosaursBe aware of the characteristics of amniotes (and which taxa are amniotes)Amniotes - turtles, lepidosaurs, & mammals (Ex: "reptiles", birds & mammals) (Saurapsids & synapsida)**** REPTILES ARE NOT MONOPHYLETIC***-appeared in carboniferousAmniotic egg - elaborate extraembryonic membranes, surrounded by shellImpermeable skin - amniotes have a much thicker epidermis w/ keratinous structure (scales, feathers & hair)Costal lung vent - Have advance method of lung ventilation, involves rib cagetemporal fenestration - skulls characterized by fenestra (openings--Started asAnapsid - no fenestra (amniotes/turtles)Synapsid - single fenestra behind orbit (synapsids, mammals)Diapsid - 2 fenestrae behind orbit ((lepidosaurs (tautarus, lizards, snakes)& (Archosaurs(crocs, dinos & birds))--Changed to 2 monophyletic groups of amniotesSynapsidsSaurapsids (diapsids + anapsids)Amniota – mammalia Reptila – testudines Diapsida – lepidosauria Archosauria - crocodyliaAVES AND MAMMALIA ARE POLYPHYLETIC TOGETHERWithin Saurapsids-Diapsida - Carboniferous of paleozoic - 30 may - Most diverse amniote lineage-Archosauria - permian pd, abundant in mesozoic----*****fundamentally associated with the great radiation of mesozoic tetrapods--Contain dinosaurs (ornithischians & saurischians)--also contain crocodilia & birds (aves)Be aware of the characteristics of ArchosauriaArchosaur Synapomorphies-Antorbital fenestra – in front of the eye-shape of orbit – skull is deep, orbit of eye shaped like an inverted triangle ratherthan being circular-teeth – laterally compressed-bipedalism – widespread but not universal-Fourth Trochanter* - distinctive area with a rough surface on ventral side of the femur--Powerful caudofemoral muscle originate on the base of the tail & inserted on the trochanter. When this muscle contracted, it retracted on thethigh, propelling them animal forwardBe aware of the characteristics of the crocodiliansCrocodiliansArose in Triassic - diverse in cretaceous3 Families:-Alligatoridae - caiman & alligator-Crocodylidae - includes largest living reptile-GavialidaeCroc Traits-Nostrils on tip of snout-secondary palate separates mouth from nasal passages-flap of tissue at base of tongue can seal mouth & throat from water-depressor mandible is a short & weak muscle that opens a crocodilians mouth-Ventricular septum in the heartCroc Behaviors-Hunt in water-ectothermsParental Care-vocalizations-help young out of eggs & transport them-young