Scientists have discovered more than 20 million years old salamander trapped in amber. Although fossil is impressive thing to find, this one, found in amber mine in the northern mountain range of the Dominican Republic, sheds a light on evolution of Caribbean islands, where it was found.
Since today there are no salamanders in the entire Caribbean area and that they lived here before is completely new knowledge. Furthermore – this tiny animal now entombed forever in amber is telling a story about its short life with traumatic end.
More than 20 million years ago this baby salamander encountered a predator in the area that today we call the Dominican Republic. Predator ripped of salamander’s leg, but it managed to escape. However, it did not survive, because soon it fell into a gooey resin deposit, where it fossilized and stayed in this shape only to be found recently.
This baby salamander is from a species that was never seen before and is now extinct. Scientists named it Palaeoplethodon hispaniolae and now researchers from Oregon State University and the University of California at Berkeley are trying to figure out what this fossil means for the ecological and geological history of the islands of the Caribbean.
The salamander baby in the fossil belonged to the family Plethodontidae, a widespread family that today is still very common in North America, particularly the Appalachian Mountains. However, scientists did not know it ever lived in the Caribbean are.
Furthermore, scientists note that no one has ever found a salamander preserved in amber and there were very few salamander fossils of other types. That is why discovery of this piece of amber with a baby salamander trapped inside was particularly exciting for the scientists.
This newly discovered species of salamanders had back and front legs lacking distinct toes, just almost complete webbing with little bumps on them. This means, that unlike other animals in that family, this species as prolific a climbers and probably lived in small trees or tropical flowering plants.
George Poinar, member of the research team, noted that “the discovery of this fossil shows there once were salamanders in the Caribbean, but it’s still a mystery why they all went extinct. They may have been killed by some climatic event, or were vulnerable to some type of predator.”
Scientists say that it is also a mystery how salamanders got there to begin with, since the fossil represents an early lineage of phethodon salamanders that evolved in tropical America. The salamander in the amber is 20-30 million years old and its lineage may go back 40-60 million years ago. In that time the Proto-Greater Antilles, a territory that now includes Cuba, Jamaica, Puerto Rico and Hispaniola islands, were still connected to North and South America.
This gives scientists several ideas of how salamanders might have ended up in current Dominican Republic. They may have simply stayed on the islands as they began their tectonic drift across the Caribbean Sea. Or they simply crossed a land bridge during periods of low sea level later.
It is also possible that some individual salamanders floated on some debris or a log across the Caribbean Sea and settled in these islands. Either way, scientists say that discovery of this fossil is going to help to better the knowledge about global events in such a distant past. It will also help to reconstruct biological evolution of Caribbean region.
There were other interesting findings in the region too. Scientists found fossils of rhinoceroses found in Jamaica and jaguars in the Dominican Republic. Furthermore, the tree that produced resin that trapped the baby salamander is most closely related to one that is native to East Africa. All this information is very helpful for scientists who are trying to reconstruct biological and geological aspects of ancient ecosystems, which means that short and dramatic life of this salamander turned out to be much more significant than that of other members of its species.