A salamander preserved in amber for at least 20 million years in what is today the Dominican Republic is proof the creatures once existed in the Caribbean, although they are all extinct in the region today, scientists say.
There's more, they report; it's from a never-before-seen species. Oh, and it's the first salamander ever found encased in amber.
The salamander — just a youngster, actually — had a really bad day, because some prehistoric predator apparently bit one of its legs off before if fell into hardening deposit of gooey resin, to be preserved for the ages.
Researchers, reporting the find in the journal Paleodiversity, have dubbed it Palaeoplethodon hispaniolae, and say it's valuable as a clue to the geological and ecological history of the Caribbean region.
Not to mention being unique.
"There are very few salamander fossils of any type, and no one has ever found a salamander preserved in amber," says George Poinar, Jr. of Oregon State University's College of Science in Corvallis.
Poinar is an expert in life forms preserved in amber, which give scientists a glimpse into vanished prehistoric ecosystems.
Finding it preserved in Dominican amber was completely unexpected, since no salamanders, either as fossils or living ones, have ever been found in the region before, he notes.
Modern relatives of the amber specimen are commonly found in North America today, especially in the Appalachians, but P. hispaniolae — and all salamanders — have long been extinct in the Caribbean, the researchers explain.
Exactly why isn't clear, Poinar says.
"The discovery of this fossil shows there once were salamanders in the Caribbean, but it's still a mystery why they all went extinct," Poinar says. Some climatic event may have killed them off or they may have been vulnerable to some particular predator, he suggests.
How salamanders got to the islands of the Caribbean in the first place is also a mystery, he says, since the fossil comes from a lineage that originally evolved in tropical America.
Though only between 20 and 30 million years old, the fossil's line may go back as far as 40 to 60 million years, when islands including modern day Cuba, Puerto Rico, Jamaica and Hispaniola were known as the Proto-Greater Antilles and were still attached to North and South America, he suggests.
Many fossils have been discovered, which is strong evidence of an earlier time when the Earth's continents were much different from today, many of them connecting and then disconnecting over eons.
"There have been fossils of rhinoceroses found in Jamaica, jaguars in the Dominican Republic, and the tree that produced the Dominican amber fossils is most closely related to one that's native to East Africa," Poinar points out. "All of these findings help us reconstruct biological and geological aspects of ancient ecosystems."
