Wednesday March 17

Wednesday March 17 - Why is the amniotic egg considered an...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Why is the amniotic egg considered an important evolutionary breakthrough? It . 1. Has a shell that increases gas exchange 2. Allows incubation of eggs in a terrestrial environment 3. Prolongs embryonic development 4. Provides insulation to conserve heat energy Reptiles The reptile clade includes the tuatara, lizards, snakes, turtles, crocodilians, birds, and the extinct dinosaurs Have scales that create a waterproof barrier Lay shelled eggs on land Mostly ectothermic - Absorb external he at as the m ain source of body he at - Exception is the birds, which are endothermic Turtles The most distinctive group of reptiles alive today All turtles have a boxlike shell m a d e of upp er and lower shields that are fused to the Lepidosaurs Two lineag es of lepidosaurs - Tuataras - Squa m at es Tuataras- lizard-like reptiles Squa m at es include the lizards and sn akes Archosaurs Includes the Dinosaurs (extinct) and the living Crocodilians and Birds
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/27/2010 for the course BIOL 1202 taught by Professor Gregg during the Spring '08 term at LSU.

Page1 / 3

Wednesday March 17 - Why is the amniotic egg considered an...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online