Biomechanical studies of the arachnid-like front “legs” of an extinct apex predator show that the 2-foot (60 centimeter) sea monster Anomalocaris canadensis was probably weaker than before. One of the largest animals to live in the Cambrian period, it was probably agile and fast, chasing soft prey in the open water instead of hard-skinned creatures on the sea floor. The study was published in the journal Proceedings of the Royal Society B.
First discovered in the late 1800s, Anomalocaris canadensis—meaning “strange shrimp from Canada” in Latin—has long been believed to be responsible for some of the scarred and crushed trilobite exoskeletons paleontologists have found. in the fossil record.
“That doesn’t make sense to me, because trilobites have a very strong exoskeleton, which they actually make out of rock, whereas this animal is mostly soft and squishy,” said lead author Russell Bicknell, a postdoctoral fellow at American researcher. Museum of Natural History’s Division of Paleontology, who supervised the work while at the University of New England in Australia.
Recent research on the armor-plated, ring-shaped mouths of A. canadensis cast doubt on the animal’s ability to process solid food. The latest study sets out to investigate whether the predator’s long, spiny front appendages can do the job.
The first step for the research team, which included scientists from Germany, China, Switzerland, the United Kingdom, and Australia, was to build a 3D reconstruction of A. canadensis from the remarkably well-preserved—but flattened— the animal fossils found in Canada’s 508-million-year-old Burgess Shale. Using modern whip scorpions and whip spiders as analogues, the team was able to show that the predator’s segmented appendages were able to grasp prey and could stretch and flex.
A modeling technique called finite element analysis was used to show the stress and strain points in this gripping behavior of A. canadensis, illustrating that its joints are damaged while grasping hard prey such as trilobite. The researchers used computational fluid dynamics to place a 3D model of the predator in a virtual current to predict what body position it would likely use while swimming.
The combination of these biomechanical modeling techniques—used in a scientific paper for the first time—paints a different picture of A. canadensis than previously believed. The animal was probably a fast swimmer, zooming after soft prey in the water column with its front limbs outstretched.
“Previous concepts were that these animals saw the Burgess Shale fauna as a smorgasbord, going after whatever they wanted, but we know that the dynamics of Cambrian food webs were probably more complex than than we thought before,” Bicknell said.
More information:
The Raptorial appendages of the Cambrian apex predator Anomalocaris canadensis were built for soft prey and speed, Proceedings of the Royal Society B: Biological Sciences (2023). DOI: 10.1098/rspb.2023.0638. royalsocietypublishing.org/doi … .1098/rspb.2023.0638
Courtesy of the American Museum of Natural History
Citation: Cambrian apex predator likely sought soft rather than crunchy prey (2023, July 4) retrieved July 4, 2023 from https://phys.org/news/2023-07-apex-predator-cambrian- sought-soft.html
This document is subject to copyright. Except for any fair dealing for the purpose of private study or research, no part may be reproduced without written permission. Content is provided for informational purposes only.