From an amber mine in the northern mountain range of the Dominican Republic, scientists discovered a first: a salamander entombed in amber.
"I was shocked when I first saw it in amber," said Professor George Poinar Jr. from Oregon State Univeristy where the specimen is deposited.
Because salamanders have soft, fragile bodies, Professor Poinar said few fossils of the amphibian exists, especially one so well preserved in amber.
"Finding it in Dominican amber was especially unexpected, because today no salamanders, even living ones, have ever been found in that region," Poinar said.
Oddly, salamanders do not exist in the Caribbean today and Dr. Poinar said it's a mystery why they went extinct.
"They may have been killed by some climatic event, or were vulnerable to some type of predator," he said.
The entombed salamander is considered to be a hatchling because of its slight bone growth and small size. It belongs to a widespread family, Plethodontidae, that is still common throughout the Americas.
Lateral view of complete specimen of Palaeoplethodon hispaniolae gen. n., sp. n. in Dominican amber. Arrow shows tip of tail. Bar = 4.3 mm
Poinar is unsure how the 20 or 30-million-year-old salamander became caught in amber but suggested that the amphibian was attacked by a predator shortly after it hatched, lost its left foreleg, then became trapped by the sticky resin as it tried to escape. He explained the region where the salamander hatched would have had a number of predators that could have attacked it.
The extant Chinanteca salamander (Bolitoglossa chinanteca) is a species of salamander in the
Plethodontidae family and related to Palaeoplethodon hispaniolae. It is endemic to Sierra Juárez, Oaxaca, Mexico.
Reconstruction drawing of Palaeoplethodon hispaniolae
The trapped specimen, newly named Palaeoplethodon hispaniolae, is part of an early line of phethodon salamanders from tropical America. It's lineage existed as far back as 60 million years ago when Cuba, Jamaica, Puerto Rico and Haiti/Dominican Republic were joined as the Proto-Greater Antilles and connected to North and South America.
Map of Proto-Caribbean land mass, connected to North and South America.
The find will help researchers to reconstruct ancient Earth. "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 said.
Dr. Poinar is part of a team who described the discovery from Oregon State University and the University of California at Berkeley in the journal Palaeodiversity.
The Cordillera Septentrional mountain range in the northern Dominican Republic where the amber was extracted.