LIFE SCIENCE

Detailed explanation-1: -The diapsid lineage (birds) and synapsid lineage (mammals), share a suite of functionally similar characteristics (e.g. endothermy) that are considered to be a result of their convergent evolution, but the candidate selections leading to this convergent evolution are still under debate.

Detailed explanation-2: -Birds evolved from a group of meat-eating dinosaurs called theropods. That’s the same group that Tyrannosaurus rex belonged to, although birds evolved from small theropods, not huge ones like T. rex. The oldest bird fossils are about 150 million years old.

Detailed explanation-3: -THE classical hypothesis for the diversification of birds and mammals proposes that most of the orders diverged rapidly in adaptive radiations after the Cretaceous/Tertiary (K/T) extinction event 65 million years ago1–3.

Detailed explanation-4: -Mammals first appeared at least 170 million years ago and lived among dinosaurs until a mass extinction event following a catastrophic asteroid impact killed off all dinosaurs except birds.