Fossil and Extinct Amphibian: Dominican Republic Salamander in Amber

Of all the tropical-climate animals that roam rain forests in the Caribbean, none of them are salamanders. That's why it's startling that a never-before-seen, now-extinct salamander, Palaeoplethodon hispaniolae, has been found fixed in amber in the Dominican Republic. Twenty million years ago, this likely slippery, prehistoric amphibian got in a skirmish with another animal, had its leg bitten off, then fell into gooey resin and was fossilized forever in amber. A tough day, to be sure. 

Researchers from Oregon State University and University of California, Berkeley recently published their findings about the Palaeoplethodon hispaniolae in the journal Palaeodiversity.

Seeing a salamander fossil, period, is surprising, as one OSU professor, George Poinar, Jr., noted. No one has ever found one preserved in amber, he said in a release.

Relatives in the same family, Plethodontidae, are still common in North America, especially in the Appalachian Mountains. This preserved salamander, however, has different feet--its back and front legs lack distinct toes, just webbing with little bumps on them. This might mean that it was less of a climber than many modern species. It could have lived in small trees or tropical flowering plants, the release said.

The preserved salamander was found in an amber mine in the D.R.'s northern mountain range. The fossil is 20-30 million years old, with lineage that may go back 40-60 million years ago when the Pro-Greater Antilles, the region that includes the islands surrounding the D.R.,was still connected to North and South America, according to a release.

It isn't clear how salamanders became extinct there, or how they got there. Maybe salamanders drifted to the Caribbean when the islands were moved on tectonic plates, or perhaps the amphibians crossed a land bridge when sea level was low. Or, they could have floated across the ocean on a log. As fossils of rhinos have been found in Jamaica, and jaguars in the D.R., each new fossil adds to the biological and geological record and might later lend info on why animals went extinct there, as the scientists have theorized, said the release.

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