Recent studies have opened a window onto the lives of sebecids, a group of Cretaceous and Cenozoic reptiles that were cousins to today’s crocodilians. These beautiful beasts turned out to be some of the greatest survivors of the mass extinction that ended the Cretaceous Period. They survived much longer than their mainland relatives had disappeared. Evidence from fossils in the Caribbean suggests that sebecids prowled the land as top predators for millions of years, demonstrating their adaptability and resilience in a changing world.
Fossils excavated from the country of Dominican Republic include a 12 millimeter-long serrated tooth. They encompass vertebrae from as far back as about 4 to 7 million years ago. These results further indicate that sebecids persisted in the Caribbean. The scarabs survived to this day despite having gone extinct in South America about 10 million years ago. This finding upends long-held beliefs about when they went extinct. It underscores their historical top-down role and their unique ecological role they played in their habitats.
Sebecids have long legs that dangle straight down from their bodies. This remarkable anatomy allows them to travel swiftly on both land and water. Unlike many of their crocodilian cousins, sebecids were terrestrial predators which most likely stalked larger prey on land. This behavior illustrates a remarkable evolutionary response. It was this adaptation that allowed them to thrive as the world’s top land predators for tens of millions of years after the dinosaurs went extinct.
“The vertebrae are the thing that really brings home that they’re sebecids,” said Lazaro Viñola López, a researcher involved in the study.
The paleontological team suggests that sebecids traveled to the Caribbean through primitive, now submerged, land bridges. They address the possibility of these creatures rafting on vegetation. Their prowess in land, air, and sea environments was crucial to that survival. Their success spread them into the most remote environments long after their kin had disappeared.
The sebecid found in the Dominican Republic would have been around two meters long. By comparison, larger species such as Barinasuchus reached lengths of 10 meters, weighing close to two metric tons. These amazing reptiles had serrated teeth to help them ambush their prey. Their unique, laterally compressed spine structure provided them with additional advantages, enabling improved gripping and killing of prey.
“[The findings] show that these [animals] were still important elements of past ecosystems until relatively recently,” explained Pedro Godoy, another member of the research team.
This exciting new evidence of sebecid fossils in the fossil record prompts further questions about their ecological importance and interactions within prehistoric environments. Scientists don’t want to bring them back for sheer curiosity— they think these massive creatures would have been ecosystem engineers, dramatically impacting species interactions and food webs.
Christopher Brochu, a paleontologist, expressed nostalgia for these ancient predators: “I really am sorry they’re gone, because they must have been totally awesome to see.” His quote rings true with a growing desire and curiosity to understand all the complex and fascinating shapes of life that used to share our planet with us.
Leave a Reply