A gigantic crustacean with a peculiar look slid across the muddy seafloor of present-day British Columbia more than 500 million years ago.
It was half a meter (1.6 feet) long and had a massive head with a helmet-like carapace, or shell, stalked eyes, and a pair of claws with hard tiny structures that looked like fingers.
This arthropod, whose discovery was published in the journal Royal Society Open Science on September 8, most likely spent its days scrounging for food in the mud.
The organism has been given the name Titanokorys gainesi, and scientists think it provides a rare peek into how some of the first animal habitats functioned.
“Understanding how predators got established is vital [in order] to understand how…other species evolved, including many animals that we still know today,” says Jean-Bernard Caron, coauthor of the paper and curator of invertebrate paleontology at the Royal Ontario Museum in Toronto.
“It reveals something about the complexity of the food web at the time, which we had assumed was a little simpler.”
Titanokorys belonged to the radiodonts, an extinct genus of arthropods that originated during the Cambrian explosion, a 540 million-year-old boom in animal variety.
Radiodonts had teeth-lined cone-shaped mouths, two frontal claws, and a network of gilled flaps along their body that they utilized to swim.
Titanokorys is a member of the hurdiid radiodont family, which is distinguished by its large, three-part head carapaces.
“What makes this specific group relevant for the Cambrian setting is that they were the top predators at the time, so they had a key role in managing the prey populations of these first communities,” Caron explains.
In the Burgess Shale, a fossil deposit in the Canadian Rockies, he and his colleagues discovered the remnants of a dozen Titanokorys animals.
There were carapace fragments, mouthparts, and claws among them, as well as one extremely well-preserved carapace.
The team used fossils of Cambroraster falcatus to recreate what the rest of its body could have looked like.
They had earlier uncovered a smaller and more common hurdiid in the same location, which occasionally included soft tissue fragments.
Caron and his colleagues thought Titanokorys and its smaller cousin’s carapaces were so strange that they called them after spaceships, calling them the mothership and the Millennium Falcon, respectively (a Star Wars allusion that eventually made it into the smaller hurdiid’s Latin name).
“The ‘mothership,’” Caron adds, “was something truly strange.” “Today, nothing compares to this.”
Titanokorys is one of the most massive animals ever discovered from the Cambrian Period when other species were barely a few millimeters long.
It also possessed a huge, oblong carapace, with the mouth and claws in front and the eyes in the back.
Titanokorys’ eyes were positioned to stare upwards, indicating that it couldn’t see what it was eating but was able to keep an eye out for larger predators.
The meter-long Anomalocaris Canadensis, the only Cambrian radiodont known to be larger than Titanokorys, could have been among them.
Titanokorys’ carapace and claws were also compared to those of other hurdiids by Caron and his collaborator Joe Moysiuk, a Ph.D. student in ecology and evolutionary biology at the University of Toronto.
Caron claims that this family featured an amazingly broad range of carapaces, with forms ranging from extended to stout, rounded to pointed.
However, the carapace form did not appear to reflect a hurdiid’s hunting strategy or ecological role, according to the researchers.
Titanokorys has a lengthy carapace and claws that were ideal for raking through the muck.
“One would think that an extended shape would be more adroit,” Caron explains.
Titanokorys, on the other hand, had a small, stubby body that made it difficult for it to slice through the water.
It didn’t have to swim very quickly, though. Rather, it may have plowed through the muck with its huge carapace.
Meanwhile, its spiky claws combed the soil, attracting prey to its mouth.
A lengthy carapace was combined with claws that weren’t equipped to dig through the muck in other species, though.
Instead, the animal’s claws had longer “fingers” with thinner and more numerous spines, allowing it to filter microscopic morsels from the surrounding water.
Titanokorys and its smaller cousin Cambroraster possessed claws that were similar in shape, implying that they hunted for the same kinds of food on the seafloor.
Caron explains, “Previously, we thought that each predator had their group of prey that they would have been consuming.”
“However, it appears that competition was a major factor in the Cambrian, possibly even among predators.”
More evidence is needed, he argues, to confirm whether these two animals were fighting over meals.
Caron says, “We’re still missing quite a bit of information.” “However, I’m expecting that with additional research in this subject, we’ll find other members of this group of radiodonts who can assist us better grasp the issue of carapace shape versus claw types.”