During the scene with Amelia in the biology lab, Wei-Chen has an affinity to the teacher's lipstick-wearing monkey, who will not leave him alone. Wei-Chen can easily recognize that the monkey is actually a male, just as the monkey can actually recognize that Wei-Chen is a monkey himself.
Did the first vertebrates evolve during the mesozoic era? No. The 1st vertebrates appeared in the fossil record about 525 million years ago during the Cambrian Period.
The first dinosaur to be described scientifically was Megalosaurus. The first dinosaur to be described scientifically was Megalosaurus in 1824, by William Buckland. Buckland (1784-1856) was a British fossil hunter and clergyman who discovered some Megalosaurus fossils in 1819 and named the reptile in 1824.