Earth’s vertebrate diversity may be far richer than anyone realized. A sweeping analysis of more than 300 studies suggests that for every known fish, bird, reptile, amphibian, or mammal species, there ...

A new study led by researchers at the University of Arizona suggests that for every recognized vertebrate species, there are, on average, two ...

Scientists have long puzzled over the gap in the fossil record that would explain the evolution of invertebrates to vertebrates. Vertebrates, including fishes, amphibians, reptiles, birds, mammals, ...

There may be twice as many vertebrates on the planet as previous estimates claimed, according to a new study published in the journal Proceedings of the Royal Society B: Biological Sciences. That's ...

518-million-year-old fossil reveals vertebrates once had four eyes and extra organs that later shaped evolution.