Paleontologists working in Idaho have discovered an ancient species of a horseshoe crab that crawled around Pangea some 245 million years ago, according to a new study published in the journal Neues Jahrbuch für Geologie und Paläontologie.
Horseshoe crabs are an odd animal that first appeared on Earth roughly 470 million years ago. The one in the study — known as Vaderlimulus tricki. — came about during the late Triassic era, right when dinosaurs first began to evolve. It had a long tail, sharp spines and a unique head shaped like the letter D. The strange creature lived off the coast of what is now Idaho, and likely swam around in warm, shallow waters.
“Vaderlimulus…has unusual body proportions that give it an odd appearance,” said lead author Allan J. Lerner, a researcher in the New Mexico Museum of Natural History and Science, in a statement.
Horseshoe crabs, both ancient and modern, belonging to the subphylum Chelicerata. That means their closest living relatives include spiders and scorpions. As a result, they have exoskeletons and, as they are not technically crabs, their spindly legs are tucked under a wide shell, Newsweek reports.
Though horseshoe crabs have been around for hundreds of millions of years, new species are quite rare. Despite their hardy appearance, and the fact that they have been around since before the dinosaurs, horseshoe crabs populations are declining all over the world. They are typically used in fertilized and some scientists use their blood to make medicine; they also have a high mortality rate and low spawn rate.
This new research gives insight into the species diversity and could help scientists get a better idea of the way the crabs have shifted over time.