Consider the phylogenetic tree. Which two organisms are most closely related, based on the tree above?

ray-finned fishes and sharks

rodents and primates

dinosaurs and crocodiles

dinosaurs and birds

Answer: dinosaurs and birds

Plentiful collection of f ossils of early birds and their most immediate predecessors has settled the century-old controversy about the origin of birds. Birds are now safely declared to evolve from a group of dinosaurs known as maniraptoran theropods. Birds have similar shape of the bones as a variety of maniraptorans have. A host of fossils have shown also that the maniraptorans lay looked alike eggs as that of birds and they resemble the birds in the way they laid their eggs also. Those reasons prove that they are most closely related.