Scientists from Oregon State University and University of California at Berkley have published a study describing the first salamander ever to be found in the Caribbean. While Lizards, which look superficially similar, are quite common there, a salamander has never been observed, until now.
The specimen has been called Palaeoplethodon hispaniolae and was found in an amber mine in the Dominican Republic. It is part of the family Plethodontidae that are salamanders that lay their eggs on land and lack lungs. They obtain oxygen through their skin.
The individual was young and was only about 18mm long. In order to examine it in detail, the team observed the salamander under a microscope. Upon closer inspection, they found that one of the front legs was actually missing suggesting it may be have been attacked by a predator just before it fell into the resin pit in which it was fossilized. The front leg that remained in tact was interesting though. It was completely rounded without toes. There was evidence of phalanges (bones in hands and feet of animals) in the fore limbs. The hind limbs were also underdeveloped. There was some webbing seen but individual digits were not observed. In most living salamanders, at least a few digits are visible. These unique digits confirmed that this salamander is a newly discovered species and not one we know of today.
How P. hispaniolae got to the Caribbean is unknown. The Greater Antilles, the archipelago which includes the Dominican Republic was once attached to North and South America so P. hispaniolae may have been one the stowaways as the archipelago migrated away from the Americas. Another possibility is by floating on driftwood as we have seen that this has happened on several occasions.
Like the migration of P. hispaniolae, the extinction is also a mystery. It may have been caused by climate change. There is evidence of a cooling period that occurred about 37 million years that may have driven the species to extinction.
Other species from the family Plethodontida inhabit in the southern United States, mainland Central America and tropical areas in South America.
The team find themselves very lucky to find a fossil like this preserved in amber. These types of fossils are especially rare and a lot can be learned from them. The study was published in the journal Paleodiversity.