Question

Question 22 3 pts pterosaurs horned dinos duckbills crocs and relatives sauropods prosauropods dome heads armored dinos other theropods birds theropods (meat-eating dinosaurs) ornithischians (bird-hipped dinosaurs) saurischians (lizard- hipped dinosaurs) dinosaurs ornithodirans (archosaurs related to birds) archosaurs (ruling reptiles) Examine the phylogeny above, and answer parts A-C. Part A: Which two groups are the closest relatives of birds and other theropods? Part B: If you formed a group of "flying things" that included pterosaurs and birds, would that be a monophyletic, paraphyletic, or polyphyletic group? Explain your answer. Part C: List three taxa included on this tree that together form a paraphyletic group

Answer 1

Part A:-

The closest relatives of birds and theropods are ornithischians and saurischians. According to latest classification under saurischia, Herrerasauridae (herrerasaurus and staurikusaurus) forms a sister group to sauropodomorpha.

Part B:-

Monophyletic because birds comes under Aves which are catogerized in monophyletic taxa . The pterosauria which had long tails descended from pterodactyloids which are shorter tails hence it comes under monophyletic taxa.

Part C:-

The paraphyletic group in this tree includes

1.archosaurs

2.Ornithodirans

3.saurischians