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.
Animal Life. The beginning of the Paleozoic era is marked by a sudden explosion of invertebrate animals, over 900 recorded species in the Cambrian period. It was only a few million years later that vertebrates appeared during the Ordovician period. The Devonian period showed an uprising in fish and other marine life. By the end of the Paleozoic era evolution had caused complex land and marine animals to exist.