Viviparity, the live-bearing mode of reproduction, has evolved independently in several vertebrate lineages, including squamate reptiles and seahorses. In reptiles, evolutionary transitions from ...

A feeding method of the extinct jawless heterostracans, among the oldest of vertebrates, has been examined and dismissed by scientists at the University of Bristol, using fresh techniques. The ...

In a lab at the University of Sydney, a female yellow-bellied three-toed skink first laid eggs, then gave birth to a live baby, all part of the same pregnancy. This is the first time biologists have ...

What really did come first--the chicken or the egg? Birds' reproductive biology is dramatically different from that of any other living vertebrates, and ornithologists and paleontologists have long ...