20-Million-Year-Old Sea Cow Fossil Reveals Bite Marks from Both Crocodiles and Sharks, Unveiling Ancient Predator-Prey Dynamics.
Scientists have discovered a fossil of an unfortunate sea cow from the extinct genus Culebratherium, a relative of modern manatees, in Venezuela, as reported by New Atlas on August 29. The fossil consists of only a part of the skull and a few vertebrae, yet it is sufficient to narrate the story of its fate 20 million years ago.
Illustration of ancient sea cow being attacked by crocodile while shark swims nearby, waiting for an opportunity. (Photo: Jaime Bran Sarmiento)
The ancient sea cow bears three deep puncture wounds on its snout, measuring up to 8 mm wide, identified as caused by a crocodile. These punctures are neat, indicating a direct bite followed by a release, suggesting that the crocodile bit down and then let go, possibly repeating this action several times. The location of the bite marks indicates that it was likely attempting to suffocate its prey.
When this method proved ineffective, the crocodile altered its strategy. A series of other bite marks with similar round punctures resulted in significant damage to the bones, along with numerous gashes and cuts. This suggests that the crocodile executed a death roll on the sea cow, a technique that modern crocodiles also use to dispatch their prey. Specifically, they clamp down with their powerful jaws and then twist their bodies to tear flesh.
The research team also identified a third set of bite marks scattered across the sea cow’s bones that looked entirely different. These were long and narrow, leaving V-shaped impressions on the bones—characteristic signs of shark teeth. One shark tooth was even found lodged in the sea cow’s neck, allowing the researchers to determine that the attacker was a relative of the extinct tiger shark. In summary, it appears that the crocodile killed the prey and fed, after which the shark rushed in to scavenge the remains.
“Our discovery is one of the few pieces of evidence showing that multiple predators attacked a single prey, providing insights into the food web in this region during the Miocene epoch,” said Aldo Benites-Palomino, a researcher at the University of Zurich and the lead author of the study. The new research was published in the journal Vertebrate Paleontology.
