Arthropods belong to an evolutionary branch – the ecdysozoa – that contains about half of all animal species, and the earliest fossil evidence of the group now dates back 550 million years ...

The fossil is of a small, worm-like creature named Uncus dzaugisi. The discovery fills a significant gap in the understanding of early animal evolution. “Scientists have hypothesized for decades that ...

Fossil evidence indicates they had sharp, beaklike jaws to snare prey such as plankton, crustaceans, and other ammonites. They were also preyed on by larger reptiles and fish. As ammonites evolved ...