How did reptilian issues that seemed one thing like crocodiles get to the Caribbean islands from South America hundreds of thousands 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 kinfolk of crocodiles.
Whereas sebecids first emerged in the course of the Cretaceous, that is the primary proof of them lurking exterior South America in the course of the Cenozoic epoch, which started 66 million years in the past. A world workforce of researchers has discovered that these creatures would stalk and hunt within the Caribbean islands hundreds of thousands of years after comparable 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 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 printed in Proceedings of the Royal Society B.
Origin story
Throughout the late Eocene to early Oligocene intervals 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 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 by way of a land bridge referred to 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 gaggle 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 often known 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 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 much like the one sebecids in all probability used after they arrived within the Caribbean islands.
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