City University of New York
HALL OF VERTEBRATE ORIGINS: Proceed back to the Hall of Saurischian Dinosaurs. Walk completely through it, and exit through the archway at the rear of the hall into the Hall of Vertebrate Origins (use map of 4th floor if necessary).
1. PTEROSAUR: Hanging from the ceiling is a skeleton of a pterosaur, a flying reptile of the Mesozoic Era (but not a dinosaur). Sketch one of the wings. Which finger forms the main support for the wing surface?
2. MOSASAUR & PLESIOSAUR: Proceed through the Hall of Vertebrate Origins. Notice the skeletons of the mosasaur and plesiosaur (hanging from ceiling) - two reptiles (but not dinosaurs) common in deposits of the Western Interior Seaway described during the first class meeting of the semester. What evidence can you cite that demonstrates that both of these animals were aquatic rather than land-dwelling?
1. DIMETRODON: Dimetrodon is an example of what are called "Pelycosaurs", i.e. "primitive" members of the mammal-like reptiles. They are primitive in the sense that they have few mammalian characteristics. What mammalian features, if any, can you see in this animal? If you are not sure (and there is no reason you should be since we haven't discussed these animals in class) look closely at the teeth. Are they all exactly the same shape? Are your teeth all exactly the same shape? (You are a mammal.)