Lecture 28 Flashcards
What is in the Amniote clade
mammals and reptiles
What is the key unifying feature of Amniotes
amniotic egg
What does the amniotic egg do
-protect from desiccation
-gas exchange
-nutrients
What forms the placenta in mammals
4 extraembryonic membranes
Adaptations for terrestrial life of Amniotes
-copulatation & internal fertilization
-waterproof skin
-muscles associated with rib cage to ventilate lungs
How many skull holes in a diapsid
two holes per side behind eye socket (ex. reptilia)
How many skull holes in a Synapsid
One hole per side (ex. mammals)
How many skull holes in an anapsid
no holes, ex (turtles)
What do skull holes do
allow for muscle attachment to control jaw movement
Characteristics of non-avian Reptilia
-skin protected by thick, dry, keratinous scales
-skin must be shed
-leathery eggshell (protects from desiccation)
What are Ectotherms
rely upon environmental heat to maintain appropriate temperature
Characteristics of turtles & tortoises
-bony dorsal and ventral shields
-skull is solid box with large openings behind eyes
-can withdraw head inside carapace
-males have intromittent organ (structure to transfer sperm)
-herbivores & carnivores
Characteristics of snakes & lizards
-lizards have external ear openings and well-developed limbs
-most species-rich group of non avian reptiles
What are Theropods
-large predators (T.Rex)
-small, fast hunters (Velociraptor)
-ancestors of birds
How many heart chambers to endotherms have
4 but reptiles have 3
