Two-Meter-Long Fossil of Lobster-Like Animal That Swam the Seas 480 Million Years Ago Discovered, Used Its Head to Catch Prey

In 2015, scientists uncovered the fossil of an ancient human-sized lobster in the Sahara Desert which gave them new insights regarding the creature. The creature in focus is Aegirocassis benmoulae species. Experts gave this name to the marine animal after Moroccan fossil hunter, Mohamed Ben Moula, who first discovered its remains, the University of Oxford stated. As per experts, the new fossil of this creature indicates that it is the earlier ever giant filter-feeder found by humans.

Researchers have found through examinations that the now-extinct species roamed the Earth 480 million years ago. The new set of fossils were discovered in Morocco’s portion of the desert on a rock, according to Smithsonian Magazine. Unlike the past specimens of this fossil, this one is not squished flat. Instead, it had raised features that enabled experts to carefully excavate it from the surrounding rock and make a 3D model.

The anatomy of the creature surprised researchers. Past studies and examinations claimed that the beings had appendages that helped them grab prey and flaps on the side to help with swimming. Experts thought there would be just one set of flaps and no legs whatsoever, but what they found was anything but that. The new set of fossils showed that the creature had two sets of flaps. The finding has been deemed important because the presence of two sets of flaps fills a huge gap in the arthropod evolution traced by experts to this date.

The fossil indicated that these marine animals grew at least seven feet (two meters) in height making them one of the biggest arthropods that has ever existed on Earth, Sci News stated. "This would have been one of the largest animals alive at the time," added Dr Allison Daley of Oxford University. As per examinations, the human-sized lobster falls into the extinct family of Anomalocarididae (or anomalocaridids).

Researchers noted that, unlike most anomalocaridids, which are apex predators like sharks,  Aegirocassis benmoulae were like present-day whales that filtered seawater to eat their food. "These animals are filling an ecological role that hadn’t previously been filled by any other animal," Dr Daley said. Filter feeding has been identified as one of the oldest methods of eating in the world. All the ancient examples available of filter feeders are of creatures who were small, this is the first time a massive creature like Aegirocassis benmoulae has been determined to be following this style. "We have found the oldest example of gigantism in a freely swimming filter feeder," Dr. Daley claimed.

Researchers have also speculated regarding the massive size of these filter feeders, and believe it could have something to do with the time in which they were evolving, according to Smithsonian Magazine. The period in question is the Great Ordovician Biological Diversification Event when many diverse marine forms came into existence at once. There were a lot of plankton in the marine ecosystem which possibly encouraged Aegirocassis benmoulae to become a filter feeder. Yale paleontologist, Peter Van Roy, explained that becoming a filter feeder took away many attacking features, and to escape becoming prey, the creatures evolved into being massive. "You're not going to have, like, big fangs or anything. So, one way of escaping from predation is just by growing so massive that there's ... simply nothing else that can tackle you," he added.