Ancient critter could be the granddaddy of shellfish
A weird marine creature that lived 500 million years ago at a time of explosive growth in Earth's biodiversity could be a forerunner of worms and molluscs, a study published on Thursday said.
Palaeontologists in China and Europe have taken a second look at fossils of a species called Cotyledion tylodes—a small animal that, when it was identified in 1999, was at first thought to be a cnidarian, or part of a group of jellyfish-like species.
C. tylodes had a goblet-shaped body between eight and 56 millimetres (0.3 to 2.2 inches) long, with a cup-shaped upper part and lower cylindrical stalk.
On the upper part, the creature's mouth lay adjacent to its anus, with the two organs connected by a U-shaped gut and encircled by a "crown" of foldable tentacles, the scientists found.
If so, its place in the family tree is wrong, says the study. It is likely to be a primitive lophotrochozoan, a branch that today includes worms and shellfish.
The study appears in the journal Nature Scientific Reports.
(c) 2013 AFP