New Research Challenges Status of Extinct Marine Predator as Apex Predator
New research conducted by an international team of scientists has challenged the long-held belief that the extinct marine animal Anomalocaris canadensis was an apex predator during the Cambrian era. The team used 3D reconstructions and biomechanical modeling to study the creature’s front appendages and found that they were not suited for catching hard prey like trilobites.
Anomalocaris canadensis, which was one of the largest animals during the Cambrian period, was previously thought to be responsible for the scarred and crushed trilobite exoskeletons found in the fossil record. However, the recent study suggests that this may not be the case.
Lead author Russell Bicknell, a postdoctoral researcher in the American Museum of Natural History’s Division of Paleontology, explained that trilobites have a strong exoskeleton while Anomalocaris canadensis would have been “soft and squishy.” This led the researchers to question the predator’s ability to process hard food.
To investigate further, the team built a 3D reconstruction of Anomalocaris canadensis using well-preserved fossils from the Burgess Shale in Canada. They compared the creature’s segmented appendages to those of modern whip scorpions and whip spiders and found that they were capable of stretching, flexing, and grabbing prey.
However, when using a modeling technique called finite element analysis, the researchers discovered that the appendages would likely be damaged while catching hard prey like trilobites. The team also used computational fluid dynamics to predict the predator’s swimming position in a virtual current.
The combination of these biomechanical modeling techniques presented a new understanding of Anomalocaris canadensis. Rather than being a predator that targeted hard-shelled creatures on the ocean floor, the creature was likely a fast and agile swimmer that pursued soft prey in the water column.
Bicknell commented on the implications of the research, stating, “Previous conceptions were that these animals would have seen the Burgess Shale fauna as a smorgasbord, going after anything they wanted to, but we’re finding that the dynamics of the Cambrian food webs were likely much more complex than we once thought.”
The study, titled “Raptorial appendages of the Cambrian apex predator Anomalocaris canadensis are built for soft prey and speed,” was published in the journal Proceedings of the Royal Society B on July 4, 2023. This research highlights the complexity of Cambrian food webs and challenges previous assumptions about ancient marine ecosystems.