A spiky, armor-plated with egg-shaped eyes, a shield on its back, and head are like a Swiss army knife submerged along the seafloor more than 500 million years ago, catching prey with a deadly pair of mouth pincers known as chelicerae.
Researchers found astoundingly well-preserved fossils of those thumb-size predators in 2012, and new research recently reported the creatures used to be a previously unknown species, received the title as Mollisonia plenovenatrix. Scientists have discovered dozens of fossils of this species lately that include preserved soft tissue of the mouthparts, together with the animals’ multiple legs and bulbous eyes.
The mouth pincers, in particular, caught scientists’ attention. Chelicerae are present in various groups of animals known as chelicerates; the group contains greater than 115,000 species alive at present, among them spiders, scorpions, and horseshoe crabs. These fossils provided the oldest proof thus far of these mouth appendages. However, these sharp pincers might have originated in an unknown species that are even older, the research stated.
Plenovenatrix had a segmented body coated with protective plates. Broad, spine-studded shields covered the creature’s rear and head, which was topped with bulbous eyes. The animal likely used its three pairs of legs to trot along the ocean bottom, the research authors reported.
Not only have been the chelicerae exquisitely preserved; however, the creature additionally sported gill-like respiratory structures that have been surprisingly similar to these in modern chelicerates. This discovers hinted that chelicerae likely first appeared in a species that predated M. plenovenatrix, the research stated.