Comparative anatomy-- please read and answer carefully, Thank you.

 

We do not have any physical indication of what extinct animals looked like in their circulatory, nervous, sensory, or endocrine systems, but we can figure them out pretty well using our knowledge of comparative anatomy. Choose any extinct craniate that has been gone at least for 40 million years or more (in other words, nothing with close, living relatives like mammoths, dodo’s, or saber-tooth tigers and ones we know solely from their skeletons – think dinosaurs, Pelycosaurs, Ichthyostega, etc.) and detail one element from three of the systems that would be present. State in detail why (in evolutionary and/or ecological terms) you believe that they have such a characteristic. Simple answers like heart, brain, eyes, etc., will not receive credit – you need to show some detail (heart chambers, eye parts, brain parts, etc).