A new study has shed light on the predatory dynamics of ancient ecosystems by uncovering evidence of a prehistoric sea cow that fell victim to not one, but two formidable predators—a crocodile and a shark.
This remarkable find provides a rare glimpse into the predation patterns of ancient creatures and offers insight into the complex food chains that existed millions of years ago.
The research stands as one of the few documented instances where a single prey animal was targeted by multiple predators during the Early to Middle Miocene epoch, a period that spanned from 23 million to 11.6 million years ago.
A deadly duel: Crocodile vs. sea cow
The study focuses on a dugongine sea cow, a member of the extinct genus Culebratherium, which was first attacked by an ancient crocodile before being scavenged by a tiger shark (Galeocerdo aduncus).
The fossilized remains of this sea cow — which included part of the sea cow’s skull and 18 vertebrae — were discovered in what is now northwestern Venezuela, specifically in the outcrops of the Early to Middle Miocene Agua Clara Formation, south of the city of Coro. A local farmer unearthed the rare sea cow fossil.
The predation marks on the sea cow’s skull provide a detailed narrative of its final moments. “Conspicuous” deep tooth impacts concentrated on the sea cow’s snout indicate that the crocodile likely initiated the attack by attempting to suffocate its prey—a common tactic among modern crocodilians. These predators often aim for the snout to incapacitate their victims quickly.
The study’s authors note two large incisions with a round starting impact, suggesting that after the initial grip, the crocodile dragged the sea cow, eventually tearing into it.
Striations and slashing marks found on the fossil suggest that the crocodile performed a ‘death roll’—a brutal maneuver still observed in today’s crocodiles, where the predator spins its body to rip apart its prey. This ancient behavior reveals a striking continuity in crocodilian predation tactics across millions of years.
Scavenger’s feast: The shark’s turn
As if the sea cow’s ordeal wasn’t enough, the fossil evidence indicates that after the crocodile’s attack, the remains were scavenged by a tiger shark. A tooth from Galeocerdo aduncus embedded in the sea cow’s neck, along with shark bite marks scattered across the skeleton, paints a vivid picture of the shark’s feast.
These findings suggest that once the crocodile had its fill, the tiger shark moved in to pick apart the remains, a behavior that underscores the opportunistic nature of these ancient predators.
Lead author Aldo Benites-Palomino, from the Department of Paleontology at Zurich, highlighted the significance of these findings in understanding ancient food chains. “Today, often when we observe a predator in the wild, we find the carcass of prey which demonstrates its function as a food source for other animals too; but fossil records of this are rarer,” he explains.
Benites-Palomino’s research emphasizes the important role sea cows played within their ecosystems, serving as a crucial link in the food chain for multiple predators.
A window into the Miocene epoch
The study’s findings offer a rare glimpse into the complex food webs of the Miocene epoch. While evidence of food chain interactions exists in the fossil record, they are typically represented by fragmentary fossils with ambiguous marks. Distinguishing between marks made by active predation and those made during scavenging events is often challenging.
However, this discovery stands out as one of the few well-documented cases of multiple predators feeding on a single prey, providing a unique snapshot of the predation dynamics during that time.
The team’s discovery of the sea cow remains was a remarkable find, not only for its scientific significance but also for the story behind its unearthing. Co-author Professor Marcelo R Sanchez-Villagra, Director at the Palaeontological Institute & Museum at Zurich, described the discovery as “remarkable,” especially given its location—100 kilometers away from previous fossil finds.
“We first learned about the site through word of mouth from a local farmer who had noticed some unusual ‘rocks.’ Intrigued, we decided to investigate,” recalls Sanchez-Villagra in the press release.
The excavation process itself was no small feat. “Excavating the partial skeleton required several visits to the site. We managed to unearth much of the vertebral column, and since these are relatively large animals, we had to remove a significant amount of sediment,” Sanchez-Villagra explains in the press release. The site’s excellent preservation conditions, attributed to the fine sediments, allowed the team to observe the predation marks in such detail.
Following the initial discovery, the team organized a paleontological rescue operation to extract the fossil , a process that took seven hours and involved meticulous extraction techniques. The subsequent preparation of the fossils took several months, with a particular focus on restoring the cranial elements to their original state.
The study was published in the peer-reviewed Journal of Vertebrate Paleontology .
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