Palaeontologists solve an ancient tentacled mystery | Susannah Lydon

Exceptionally preserved fossils have enabled researchers to place a tricky group of extinct marine animals on the tree of life

There are some fossils it's difficult to get enthusiastic about. Don't get me wrong: as someone whose PhD focussed on the fossil equivalent of tea-leaves, my threshold for getting excited is a lot lower than most people. But when you're studying undergraduate palaeontology there's an awful lot of extinct shelly things you must learn about. Contrary to the popular conception of what palaeontologists study (dinosaurs!), marine invertebrates with mineralised hard parts are the mainstay of working with fossils.

There are some familiar groups that, although they are extinct, we do know a fair bit about. Trilobites and ammonites fall into this category: we have a good sense of their evolution and diversity through time, and have inferred a fair bit about their biology. There are other groups that are less well understood. We've got lots of shells, but we don't know what the soft bits of the animal looked like, and we don't know where they fit on the tree of life. In short, they are a bit of an embarrassment. Luckily, there are palaeontologists who rise to the challenge.