Imagine a crocodile built like a greyhound—fast, lean, and fierce.
That’s what a sebecid was. These land-dwelling predators could grow up to 20 feet long and once ruled South America after the dinosaurs went extinct.
For years, scientists believed sebecids never reached the Caribbean. But recent fossil discoveries tell a very different story.
It all started with a mystery. Strange fossilized teeth were found in the Dominican Republic, Cuba, and Puerto Rico.
The teeth looked like they belonged to a powerful meat-eater, but no one could identify the creature.
For decades, scientists had only teeth—no bones—making it impossible to know exactly what animal they came from.
That changed in 2023, when a research team found not only a tooth but also two vertebrae in the Dominican Republic.
It was just enough to confirm the identity: a sebecid. This meant that giant, land-based predators once roamed the Caribbean millions of years longer than scientists had thought.
These sebecids were the last survivors of a group of ancient crocodile relatives called Notosuchia. Unlike today’s crocodiles, most notosuchians lived entirely on land and hunted like dinosaurs—running on long legs and tearing into prey with sharp, serrated teeth.
After the mass extinction 66 million years ago, sebecids were the only notosuchians left. They became the top predators in South America.
But how did they get to the Caribbean?
The sea between the islands and the mainland would have been a major obstacle. The fossils give new support to an idea called the GAARlandia hypothesis, which suggests there was once a chain of land bridges or islands connecting South America to the Caribbean, allowing animals to cross.
This discovery changes how we understand the Caribbean’s ancient ecosystems. These islands weren’t always dominated by birds, snakes, and small reptiles. Long ago, they had powerful, land-hunting predators too.
Paleontologist Jonathan Bloch said this find shows how little we still know about life in the tropics millions of years ago. While most fossils in the Caribbean come from caves or underwater holes and are relatively young, scientists are now working harder to find older fossils from deeper time periods.
The sebecid fossil was found only because a road was being cut through a fossil bed—something that disappears quickly in the Caribbean due to weather and vegetation. Thanks to fast action by local scientists, a big piece of history was saved.
And this is just the beginning. Recent discoveries also include sea-dwelling mosasaurs and ancient sloths. The sebecid, researchers say, is only the tip of the iceberg.
Source: Florida Museum of Natural History.
