BIOL 111 Lecture Notes - Lecture 19: Amphisbaenia, Squamata, Lepidosauria

• School: McGill University
• Department: Biology
• Course: BIOL 111
• Professor: Rudiger Krahe

Document Summary

Biol 111 lecture 19 reptiles & birds. Lecture date/time: nov 12th, 2015 / 10:35-11:25 am. Squamates: snakes: no limbs; 200+ vertebrae; highly kinetic skull (ex. can unhinge their jaws & intake food larger than their skull); vomeronasal organ (is in other organisms too) pheromones, communication. Squamata: amphisbaenia: limb girdles much reduced (no legs except in bipes); eyes reduced, no ear openings; scales fused into rings (annuli) encircling body; made for burrowing. Spend much of their time in water (embryonic development still on land) They build their nest on land or floating piles of vegetation; all are carnivorous. Consider: how to occupy extreme and/or variable environments? (thermoregulation) & how to get up into the air? (feathers, better lungs, lighter bones) The ancestor to birds was probably a theropod dinosaur. Shared characteristics of birds & dinosaur ancestor: Bipedal, 3 hind toes, carnivorous, 4-chambered heart, similar lungs, feathered, hollow bones, parental care of eggs & juveniles.