conodont

Extinct eel-like organism 520–240 million years old. Several thousand species have been described, ranging from 1–40 cm/0.4–15.8 in in length. They were predators, and, following the discovery of a large fossil in South Africa in 1995, are believed to be the first vertebrates. This fossil of a 40-cm/15.8-in conodont shows fossilized soft tissue including muscle and eyes. It has eye muscles, an exclusively vertebrate feature, and ‘real teeth’.

Conodont fossils consist mainly of teeth, and are often abundant, especially in Upper Cambrian and Triassic limestone. They were first discovered by Russian naturalist Christian Pander (1794–1865).