Scientists have found a remarkably preserved salamander dating back 40 to 35 million years that still contains the last meal it ate.
Published in PeerJ, the discovery was led by a team of paleontologists from France and Switzerland. The specimen is Phosphotriton sigei, and is the only one of its kind. It was first discovered in the 1870s, but had never been studied in detail until now.
Using the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, the team were able to peer inside the specimen, revealing startling details. This salamander belongs to the same family as the fire salamander, which is still alive today.
Inside the specimen, the team found the remains of frog bones in its stomach. Salamanders almost never eat frogs, so it’s unclear if this was a last resort meal or perhaps a dietary choice for this species.
“This fossil, along with a few others from the same lost site, is the most incredibly well-preserved that I have seen in my entire career,” said Michel Laurin, from the Museum of Natural History in Paris, in a statement. “And now, 140 years after its discovery, and 35 million years after the animal died, we can finally study it, thanks to modern technology. The mummy returns!”

The study was able to reveal that the animal’s soft organs are still conserved under its skin and bones, including its lung, nerves, and gut. Fossils containing soft tissue like this are extremely rare, but they offer an incredible insight into what these animals ate and how they lived.
Only the trunk, hip, and part of the hind legs were preserved in this fossil. Using synchrotron technology, which delivers a powerful source of X-rays, the team were able to peer inside the fossil without having to actually cut it open. This revealed six kinds of organs, and also skin and a portion of the skeleton.
“These are among the oldest known cases of three-dimensional preservation of these organs in vertebrates and shed light on the ecology of this salamander,” the team wrote in their paper.