An international group of scientists has studied the extremely well preserved fossil of an ancient reptile that resembles a dolphin that lived in the ocean in the present territory of Germany, about 180 million years agoand has found unexpected features that make it one of the most mysterious animals of the Jurassic.
According to the study, published in the journal Nature and conducted by researchers at the State University of North Carolina (USA) and Lund University (Sweden), molecular and microstructural analysis has shown that this ancient marine reptile, classified as ichthyosaur Stenopterygius, resembled to a modern dolphin not only in appearance: it was probably warm-blooded, he had insulating fat and used its coloring as a camouflage before his predators.
"The ichthyosaurs are interesting because they have many characteristics in common with the dolphins, but they are not connected to those mammals living in the sea", says a research co-author, Mary Schweitzer, professor of biological sciences at the University State of North Carolina "We are also not very sure of their biology. features in common with living marine reptiles, like turtlesbut we know from the fossil record, which was viviparous, associated with warm blood, "he added.
Extremely well preserved
Johan Lindgren, associate professor at the University of Lund and lead author of the study, emphasizes that "both the contour of the body and the remains of its internal organs are clearly visible". "Surprisingly, the fossil is so well preserved that it is possible to observe layers of individual cells within the skin"says the scientist.
This conservation status allowed researchers to identify the cellular microstructures they contained pigment organelles inside the skin, as well as traces of a internal organ that is believed to be the liver. They also observed chemically compatible material with vertebrate fat, which is found only in animals that can maintain body temperature regardless of environmental conditions.
After applying a series of high-resolution analytical techniques, scientists found chemical evidence of subcutaneous fat in the fossil. "This is the first direct chemical test of warm blood in an ichthyosaurbecause fat is a characteristic of warm-blooded animals, "says Schweitzer.
Overall, the results of the researchers indicate that the Stenopterygius had a skin similar to that of a whale and a color similar to that of many living marine animals, dark in the upper part and lighter in the lower part, which would provide a camouflage before its predators .