The oldest mammal hair that’s ever been found preserved in amber dates back to the Early Cretaceous period between 105 and 110 million years ago. The three strands of mammal hair and dinosaur feathers were discovered at Santa Maria mine which is located in Teruel (near Ariño), Aragon, eastern Spain.
The reason why the hair and feathers were “exceptionally preserved” in the amber was because of a “pull off vestiture” which means that the animals would have rested against the sticky resin while sleeping or resting against a tree and once it hardened up, it would have pulled the hair/feathers off of the animal.
Professor Xavier Delclòs from the University of Barcelona, an author of the study, stated, “The feature of the process described in this research is that a somewhat long time must pass between the animal’s contact with the resin and the pulling off of the vestiture.”
While mammal hair had previously been found imprinted in fossils dating back 160 million years, the oldest one that was preserved dated back around 100 million years ago (prior to this new discovery).
After experts analyzed the pieces, they were able to confirm that the hair belonged to a mammal and the feathers most likely came from an extinct bird. Sergio Álvarez-Parra, a doctoral student at the University of Barcelona and another author of the study, explained this further, “The determination of both findings is very complex, but it is likely for the feather remains to correspond to the extinct birds Enantiornithes, like other feathers in amber.”
He went on to say, “Regarding the lock of hair, we should consider that the surface scale pattern is similar to the current mammalian hair.” “Ariño was already known for its vertebrate fossils, such as the dinosaurs Proa valdearinnoensis and Europelta carbonensis, but no-one thought we could find remains from vertebrates included in amber.”
Professor Delclòs added that “the findings of this study and the new process shed light on the complexity of ecosystems during the Cretaceous.”
Spain is known for their many fossils that date back to the Cretaceous period, but the fact that they found hair and feathers so well preserved in amber was a definite surprise. The study was published in the journal Scientific Reports where it can be read in full.
Pictures of the mammal hair and feathers that were preserved in amber can be seen here.