Spiky Slug May Solve Mollusk Mystery

Scientists now have help in figuring out the evolution of mollusks as a tiny, hat-like shell adorning a 478-million-year-old species is discovered recently.

Mollusks, which Live Science noted to be a diverse group of invertebrates both land and water dwellers, have always been a mystery. It remained unclear for years whether they evolved from shell-less ancestors or if this particular part is innate in them. Today, it seems that scientists can now confidently say that their ancestors had one shell, thanks to the newfound species.

These newly discovered specimens -- seven of them in all -- were actually found in the late 2000s by Mohamed "Ou Said" Ben Moula, a self-taught collector who uncovered possibly thousands of specimens with fossilized soft tissues in Fezouata Biota in Morocco. Ben Moula, who has been working hand in hand with paleontologists at Yale, shipped the fossils to Connecticut so that they can be further studied.

Out of all his samples, two of the specimens were seen to be complete, which allowed researchers to examine their anatomy in detail. The study's co-lead researcher, Luke Parry, who is a doctoral student in the Department of Earth Sciences at the University of Bristol in England, shared, "I describe them as an armored, spiny slug with one single shell at the head end."

The newly discovered animal is believed to reach up to 12 cm long. It is named the Calvapilosa kroegeri, which is a reference to the hairy shell that covered its head together and is a nod to Björn Kröger. The Guardian also reported that the discovery of this ancient mollusk sheds light on other previously discovered fossils, revealing that a number of older creatures may be mollusks, thanks in part to the study that showed similarities in structure to the Kroegeri.

Martin Smith, a paleontologist at the University of Durham who was not involved in the study, described the find to be exciting. He stressed on the importance of the fossil by saying that the find could help work out what modern mollusks could have in common with their ancestors.