Some 40 million years before the dinosaurs dominated Earth, a different sort of apex predator roamed the Gondwana supercontinent during the late Palaeozoic ice age: a massive, eight foot-long ...

and chambered hearts developed in the Early Palaeozoic (540-350 million years ago) period. The fossils showed to the team that many of these features were also present in early fishes. Hence there ...

This is a synapomorphy for the crown group of the Echinoidea, and is also true for all post-Palaeozoic echinoids, bar one, Tiarechinus. By contrast almost all Palaeozoic echinoids have a test which ...