But back to the tree of life: birds' descent from Theropods ... per definition, reptiles." This is why phylogeny is valuable, because it can reveal that organisms that look very different are ...

Both birds and reptiles are descended from the group Reptilia, which are diapsids, or animals with two openings on each side of the skull. So from a phylogenetic standpoint, birds are reptiles.

Both birds and reptiles are descended from the group Reptilia, which are diapsids, or animals with two openings on each side of the skull. So from a phylogenetic standpoint, birds are reptiles. But ...

The resulting phylogenetic estimate offers novel insights into the rapid radiation of modern birds and provides a taxon-rich backbone tree for future comparative studies.” By updating the family ...

Jarvis et al., in Science, Vol. 346; December 12, 2014 (left tree); “Higher-order phylogeny of modern birds (Theropoda, Aves: Neornithes) based on comparative anatomy,” Part II: “Analysis ...