A newly published study by the University of Bristol discovered that an ancient slug fossil found several years ago had a protective "armor" of small spikes. The discovery illuminated hints of evolution of mollusks, revealing that they didn't exactly have shells, and weren't entirely without protection either.
The fossils that were enthusiastically discovered several years ago by a collector in Morocco, which dates back to 478 million years. It gives us a glimpse of the distant past of planet earth, where "evolution" could have had prevailed.
The unique-looking ancient slug is spiky, composed of small spikes. The spikes were likely used as a defense mechanism to avoid being eaten. The slug is also believed to have had a helmet looking, small single shell.
According to SpaceDaily, the small 'hat' helmet sheds light on the evolution of mollusks, helping to resolve the speculation over whether they evolved from critters with no shells or multiple shells. The slug's radula have also stirred debates surrounding other creatures with similar teeth arrangements, whether or not they belong in the mollusk family. However, the observations of this particular study concluded that the radula of the fossil belongs to the mollusk family, and not some other creature.
Dr Jakob Vinther, from the Schools of Biological Sciences and Earth Sciences, led the study, which is published this week in Nature. He said, "The molluscs are amongst the earliest animals identifiable in the fossil record, however determining what their ancestor looked like is difficult since many of the groups appear within a small window of time, making the sequence of evolutionary events difficult to piece together."
Two out of the seven fossils discovered are said to be complete. The slug has since been termed "Calvapilosa kroegeri," a name inspired by the creature's spikes.
Vinther concluded saying, "If we trace back the evolution of chitons, we can see that the number of their shells has increased with time. It is therefore likely that the ancestor to all molluscs was single-shelled and covered in bristle-like spines, not dissimilar to Calvapilosa kroegeri."
