The researchers, who have just published their findings about the new salamander in the journal Paleodiversity, have named the creature Palaeoplethodon hispaniolae.
The family in which the salamander belonged, Plethodontidae, is common in North America, especially the Appalachian Mountains. But the newly discovered salamander did not have distinctive back- or front-leg toes (see artist's conception above). Instead, it had a kind of webbing that might have made it a not terribly expert climber, when compared to some species today, the scientists said. As a result, they say, the salamander may have lived in smaller trees or on tropical flowering plants.
The team found its all-star specimen in an amber mine in a mountainous region between Puerto Plata and Santiago.
Questions yet to be answered, the researchers say, include why the salamanders disappeared and how they came to be on the island in the first place.
"They may have been killed by some climatic event, or were vulnerable to some type of predator," said Poinar, of the animals' disappearance.
As for their presence on the island, the scientist say the salamanders may trace back 40-60 million years ago, to when today's Greater Antilles were still joined to North and South America. Perhaps they simply stayed with the islands as they drifted. Or they may have crossed a land bridge at periods of low sea or even drifted to the islands on debris such as logs.