Experts have found the oldest pieces of mammal hair as well as the feather of a long-extinct feathered dinosaur preserved in amber.
Scientists say the two different sets of remains were found at two different sites in the province of Teruel, in the north-central Spanish region of Aragon, and added that they are aged between 105 and 110 million years, dating back to the Early Cretaceous period.
Luis Alcala, from the Palaeontology Foundation of Teruel-Dinopolis, told Real Press that some of the remains are the oldest example of mammal hair ever found preserved in amber and that the feathered dinosaur was an ancestor of modern birds.
The samples were found in two separate pieces of amber some 40 kilometres (24.8 miles) apart during recent excavations of an amber mine in Santa Maria, where eggs of Proa valdearinnoensis and Europelta carbonensis dinosaurs have been discovered in the past. One of the samples contains feathers from the bird-dinosaur and the other hairs from the mammal.
“Both remains were found in very small amber pieces that had to be prepared in a lab and needed a special methodology to see what they contained”, he explained, adding that in “amber it is easy to find insects or small invertebrates, but it is more difficult to find vertebrate animals remains” like the ones found at both sites.
The animals lived alongside the dinosaurs at around the same time coal was formed from leafy forests in the region, Alcala explained.
“The pieces of amber are very small, for example, the one with the feathers is only four millimetres,” he said.
The experts reported the discovery in the magazine Scientific Reports after years of study.
The team observed that the samples were uniquely preserved through “pull off vestiture”, where small sections of feather or hair from a live individual get stuck after the animal came into contact with the resin and stayed long enough for the resin to harden around the fibres.
“The position of the feather and the hairs was special, they were not hairs or feathers that were shed and fell into the resin, but they were perfectly ordered and that means that the animal might have been in contact with the amber long enough for the resin to harden”, Alcala explained.
“These animals, therefore, might have been resting or sleeping at the time that the resin hardened”, he added.
Due to the small size of the remains and the lack of information about the kind of mammals and flying dinosaurs living on the Iberian Peninsula during the Early Cretaceous period, the remains cannot be linked to a specific species. However, they can be linked with a general group.
In the case of the bird-dinosaur, the feathers belong to the Enantiornithes family, which are the ancestors of contemporary birds, while the mammal remains belong to the Mustelidae family, which now includes badgers, weasels, ferrets, otters, minks and wolverines, for instance.
Alcala said: “They might be a new species. If we find the remains of a mammal at the same site, something that could be possible as there are hair remains, then it would certainly be a new unknown mammal”.
At the time, the animals lived by an estuary near the sea, with fresh water and forest, as the current Mediterranean sea covered the coast of Catalonia and Valencia.
“There were also small size dinosaurs with feathers living with the carnivorous dinosaurs, the ones we all know from the movies.
“Feathers are not only found on birds, but were also on terrestrial animals and were not used to fly, but to provide warmth and comfort or even to identify the animals during the mating season”, he said, adding that there were small animals with feathers that were so light that they ended up evolving to fly.
These flying dinosaurs had teeth instead of beaks and were able to hunt insects and worms.
Scientists believe that the mammal that the second sample came from was about the same size as a mouse and would hunt at night in order to escape from predators like snakes and reptiles, and hid in dens during the day.
Asked about the possibility of bringing the dinosaurs back using the remains, Alcala said that it is currently impossible as DNA can only currently be recovered from samples up to 200,000 years old due to degradation.
However, Alcala believes that there might be future technology or new archaeological discoveries that could make it possible: “Maybe there is a strange site somewhere we do not know yet with a lot of possibilities of preservation or maybe there will be a new technology in the future to get the DNA from those new discoveries, but so far it is speculation”, he said.
“I would never put my efforts and investments to bring back extinct species, but I would focus on avoiding current species from becoming extinct, like whales or animals living in the Amazon.
“It is surrealist to want to recover an extinct species and go on killing what we have now.
“I would rather keep the current biodiversity. Instead of being a crazy professor let’s be responsible human beings”.
The research team includes Sergio Alvarez Parra, Xavier Delclos (both from Barcelona University), Monica M. Solorzano Kraemer, from the Senckenberg Museum of Natural History in Frankfurt am Main, and Luis Alcala and Enrique Penalver from the Geological and Mining Institute of Spain.