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

According to the data considered by its authors—a team from the University of Sussex (UK) and Lund University ...

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, ...

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

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 ...

An illustration of a four-eyed myllokunmingid, a jawless fish that lived more than 500 million years ago Xiangtong Lei and Sihang Zhang Many spine-bearing creatures, or vertebrates, have a curious bit ...

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 ...