Scientists discover ‘spaceship’ Cambrian predator
Around 540 million years ago, the world was not what it is today. Animal life had only just begun to flourish, swiftly recovering from some of the most devastating natural conditions the Earth has ever seen. Much of this evolution, as it turns out, unfolded through the vicious maws of predation. Paleontologists call this dramatic shift in global ecology the “Cambrian Explosion.”
The Cambrian Explosion, while occurring much more slowly than the name suggests, was a major turn in evolutionary history. Hard bones began to appear in the fossil record, the result of which was the actual formation of fossils: Rather than the soft-tissued creatures that came before (which would readily decompose after death), these new hard-bodied organisms would go on to lithify, get subsumed into rock layers, and eventually face discovery by eager paleontologists hundreds of millions of years later.
Recently, one such discovery — led by Jean-Bernard Caron at the Royal Ontario Museum in Canada — has yielded another predator that might have helped spur this evolutionary change; the find helps show which predators might have been responsible for early animals and their adoption of these defensive hard body parts.
The discovery, published by the Royal Society earlier this month, shows a creature that looks conspicuously similar to the Millennium Falcon from Star Wars. This is, in fact, partly where the thing got its name: Cambroraster falcatus. Regardless, the creature is thought to have roamed the Cambrian waters as a merciless killer.
More specifically, the new species was unearthed in the Burgess Shale, a famous paleontological site in the Canadian Rockies. The site dates back to 507 million years ago, placing the spaceship-like predator in the middle of the Cambrian. Amazingly, Caron and his cohort discovered a near full-body version of the species preserved in the ancient rock. And, even more amazingly, they discovered that the species had been found in fragments before, mislabeled and stored in museum depots.
What the combined findings revealed was that Cambroraster was actually ubiquitous at the time, stretching through waters all the way from North America to China (although 500 million years ago the continents were not where they are today). The find helps show that previously discovered apex predators were not the only game in town — far from it.
Previously, the only predator scientists knew to prowl the Cambrian seas was a giant shrimp-like monstrosity by the name of Anomalocaris. Anomalocaris was a formidable ocean predator for its time. Measuring a length of up to 2 meters (6 feet), the thing would roam the sandy ocean floors looking for prey.
Cambroraster falcatus, while not as large as Anomalocaris, was similar in many regards. Like Anomalocaris, many of the unearthed fossil sites show that the thing aggregated into groups with others of its kind. There are several hypothesized reasons for this. One possibility is that it might have hunted in these groups to disorient its prey. Another is that these were nesting sites. Either way, the creature had a handful of social proclivities.
Another similarity to Anomolocaris is that Cambroraster would sift through sands of the ocean floor with its appendages to unearth hidden prey. Anomolacaris would hunt with its shrimp-like arms, while Cambroraster would use its claws.
More generally, Cambroraster had the traits of a horseshoe crab. It was an arthropod with an exoskeleton that had a round mouth lined with teeth. The front of its body was adorned “with comblike claws it could hold out like a basket.” While Cambroraster and the horseshoe crab are not closely related, the superficial resemblances are there.
Ultimately, the thing helps to contextualize the types of predators that might have helped trigger the Cambrian Explosion and thrive afterward. While Cambroraster definitely appeared after the initial “explosion” took place, it had the jaws and teeth that might have helped spur the explosion in the first place. Either way, the Millennium Falcon-esque creature was not something to be trifled with. Cambrian critters likely learned this the hard way.