How did reptilian issues that appeared one thing like crocodiles get to the Caribbean islands from South America hundreds of thousands of years in the past? They most likely walked.
The existence of any prehistoric apex predators within the islands of the Caribbean was once doubted. Whereas their absence would have most likely made it much more of a paradise for prey animals, fossils unearthed in Cuba, Puerto Rico, and the Dominican Republic have revealed that these islands had been crawling with monster crocodyliform species known as sebecids, historical family members of crocodiles.
Whereas sebecids first emerged throughout the Cretaceous, that is the primary proof of them lurking outdoors South America throughout the Cenozoic epoch, which started 66 million years in the past. A global staff of researchers has discovered that these creatures would stalk and hunt within the Caribbean islands hundreds of thousands of years after related predators went extinct on the South American mainland. Decrease sea ranges again then might have uncovered sufficient land to stroll throughout.
“Diversifications to a terrestrial way of life documented for sebecids and the chronology of West Indian fossils strongly counsel that they reached the islands within the Eocene-Oligocene by way of transient land connections with South America or island hopping,” researchers mentioned in a examine just lately printed in Proceedings of the Royal Society B.
Origin story
In the course of the late Eocene to early Oligocene durations of the mid-Cenozoic, about 34 million years in the past, many terrestrial carnivores already roamed South America. Together with crocodyliform sebecids, these included huge snakes, terror birds, and metatherians, which had been monster marsupials. Right now, the ocean ranges had been low, and the islands of the Jap Caribbean are thought to have been linked to South America by way of a land bridge known as GAARlandia (Higher Antilles and Aves Ridge). This isn’t the primary land bridge to doubtlessly present a migration alternative.
Fragments of a single tooth unearthed in Seven Rivers, Jamaica, in 1999 are the oldest fossil proof of a ziphodont crocodyliform (a bunch that features sebecids) within the Caribbean. It was dated to about 47 million years in the past, when Jamaica was linked to an extension of the North American continent referred to as the Nicaragua Rise. Whereas the tooth from Seven Rivers is believed to have belonged to a ziphodont aside from a sebacid, that and different vertebrate fossils present in Jamaica counsel parallels with ecosystems excavated from websites within the American South.
The fossils present in areas just like the US South that the ocean would in any other case separate counsel extra than simply associated life kinds. It is attainable that the Nicaragua Rise supplied a pathway for migration just like the one sebecids most likely used after they arrived within the Caribbean islands.
