How did reptilian issues that regarded one thing like crocodiles get to the Caribbean islands from South America tens of millions of years in the past? They in all probability walked.
The existence of any prehistoric apex predators within the islands of the Caribbean was once doubted. Whereas their absence would have in all probability 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 have been crawling with monster crocodyliform species referred to as sebecids, historic family members of crocodiles.
Whereas sebecids first emerged throughout the Cretaceous, that is the primary proof of them lurking exterior South America throughout the Cenozoic epoch, which started 66 million years in the past. A global workforce of researchers has discovered that these creatures would stalk and hunt within the Caribbean islands tens of millions of years after related predators went extinct on the South American mainland. Decrease sea ranges again then may have uncovered sufficient land to stroll throughout.
“Variations to a terrestrial way of life documented for sebecids and the chronology of West Indian fossils strongly recommend that they reached the islands within the Eocene-Oligocene by way of transient land connections with South America or island hopping,” researchers stated in a examine just lately revealed 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 monumental snakes, terror birds, and metatherians, which have been monster marsupials. At the moment, the ocean ranges have been low, and the islands of the Japanese Caribbean are thought to have been related to South America through a land bridge referred to as GAARlandia (Larger Antilles and Aves Ridge). This isn’t the primary land bridge to probably 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 related to an extension of the North American continent referred to as the Nicaragua Rise. Whereas the tooth from Seven Rivers is assumed to have belonged to a ziphodont apart from a sebacid, that and different vertebrate fossils present in Jamaica recommend 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 recommend extra than simply associated life varieties. It is attainable that the Nicaragua Rise supplied a pathway for migration just like the one sebecids in all probability used once they arrived within the Caribbean islands.
