A body fossil of a thorny-headed worm (Acanthocephala) has been dated to the Jurassic period, about 165 million years ago. It has characteristics of both Acanthocephala and tiny animals called ...

The Jurassic fossil Juracanthocephalus reveals a key evolutionary link between rotifers and parasitic acanthocephalans, resolving debates about their origins and anatomy. A research team from the Nanj ...