Amniote origins and nonavian reptiles

• Amniotes arose from anthracosaurs during carboniferous period
• Amniotes seperated into 3 groups : Anapsids (turtles) Diapsids (lizards) and synapsids (mammals)
• 4 groups of diapsids : 1. Ichthosauria (extinct), saueopterygia (extinct), Archosauria (birds) and Lepidosauria (lizards)
• temporal fenestrae - lighter skull and changes in jaw musculature (large muscles to move lower jaw, increases static pressure, and shifts to terrestrial feeding)
• Clade amniota derived characteristics: amniotic egg, thicker waterproof skin, rib ventilation of lungs, stronger jaws, high pressure cardiovascular system, water conserving excretion, expanded brain and sensory organs.
• Amniotic egg parts : amnion (cushion) allantois (waste) chorion (respitory surface) shell(protection)
• Non-avian reptile characteristics: amniotic eggs, more developed lungs, ectothermic, scales
• Scales are made of beta-keratin
• Crocodiles scales remain throughout life
• Lizards and snakes shed old scales
• Turtles have scutes, plate like modified scales
• Order testudines - turtlesk have carapace and plastron
• order testudines - have bony layer, fusion of vertebrae and ribs
• order testudines lack teeth but have a tough keratinized beak
• order testudines have interna fertilization, male plastron curved
• order testudines - low temp are male high temp are female
• senses of order testudines - poor hearing, good sense of smell and color vision, excellent navigation abilities
• order squamata - snakes and lizards, suborder sauria lizards, suborder sperentenes
• suborder serpentenes have no pectoral or pelvic girdle, and highly kinetic skull
• kinectic skull- lost demral bone ventral and prosterior to lower temporal opening
• Sensory organs of serpentenes- poor vision (no eyelids), feel vibrations at low frequencies, chemical senses used to hunt prey
• Jacobson's organ - sits above roof of mouth by flicking tongue it gathers chemicals from the air
• Pit organs- heat sensing
• suborder serpentines - one lung, no external ears and no eyelid
• Suborder amphisbaenia- worm lizards
• suborder amphibisbaenia - have cyclindrical bodies, no external limbs, and eyes hidden beneath skin
• Order sphenodonta- tuatara
• tuatara slow growing and slow reporduction, 10-20 years until secual maturity, 12-15 months from copulation to hatching, and lay eggs every 4 years
• Order crocodilia - osteoderms (armor of bones)