Paleontologists Daniel Falk and Prof. Maria McNamara, together with scientists from Ireland, Germany and the UK, studied 45-million-year-old fossil frogs from the Geiseltal site in central Germany. Remarkably, the fossils show full body outlines of the soft tissues. The team discovered that the excellent condition of the fossil frogs is due to preservation of ancient skin remnants. The study is published in the journal Scientific Reports.

The team studied the fossils with high-precision techniques including scanning electron microscopy, synchrotron-X-ray analyses, and infrared spectroscopy. These techniques were not available when the fossils were first discovered in the early twentieth century.

"The quality of preservation of the fossil frog skin is amazing—even subcellular structures, such as collagen fibers, are preserved," said study lead, Ph.D. researcher Daniel Falk. "The skin of the frogs is replicated in the mineral calcium phosphate, which helped it survive for millions of years."