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The Discovery Of A Fossil Of 450 Million Years Old Reveals A Strange Sea Creature That Is A Hybrid Of An Insect And A Spider

According to a description in the journal Paleontology, the creature named Tomlinsonus dimitrii lived during the Ordovician period about 450 million years ago, belonging to a completely new species in the group of prehistoric arthropods Marrellomorph.

Simulation of the newly discovered species Tomlinsonus dimitrii. Photo: Royal Ontario Museum

Tomlinsonus dimitrii is only 6 cm long and can fit in the palm of a human hand. It has an ornate head shield with two curved horns covered with feather-like spikes. The creature’s multi-segmented body has both insect-like and spider-like features.

“Beneath its head is a pair of extremely long limbs. These are most likely used to detect obstacles on the seafloor. Tomlinsonus appears to be blind because it has no eyes,” said lead author Joseph Moysiuk of the study. , a doctoral student in ecology and evolutionary biology at Canada’s University of Toronto, said.

The fossil Tomlinsonus dimitrii is preserved almost intact. Photo: Royal Ontario Museum

Tomlinsonus dimitrii is a mollusk, making the new discovery even more astonishing. The creature’s fossils unearthed at the Paleo Pompeii quarry near the shores of Lake Simcoe in Ontario are in “exceptionally good” condition.

“We didn’t expect to find a mollusc at this site. When we think of fossils, we usually think of things like bones and hard shells. Preservation of soft tissue is rare, having only been recorded at this site. several places around the world,” Moysiuk added.

The Simcoe Lake area was once underwater and was part of the shallow tropical sea that covered much of what is now Canada. Over millions of years, the seabed was gradually buried by storm-induced sediments.

The team hopes the new discovery will help fill a gap in the fossil record of prehistoric arthropods. The specimen Tomlinsonus dimitrii is now in the collection of the Royal Ontario Museum and is on display in the Willner Madge room as part of an exhibition entitled “Dawn of Life”.