Scientists have known fossil flowers of ancient marine reptiles that lived 180 million years ago.
Blubber is a thick layer of fat found under the modern marine mammal skin such as whales.
His discovery in the ancient "sea monster" – namely anthithosaus – seems to confirm that the animal has been very cold, rare in reptiles.
Its skin is similar to modern whales and dolphins, after losing the typical characteristic of its ancestors.
The researchers say that the skin is smooth, still slightly flexible, and keeps evidence of the camouflage pattern of the animal.
The sea reptiles were anti-shadow – darker on the upper and light side on the floor. This offset the shadow effects of natural light, making the animal more difficult to see.
"Ichthyosaurs are interesting because they have many features common with dolphins, but are not closely related to mammals living in the sea," said co-author Mary Schweitzer , professor of biological sciences at the North Carolina State University (NCSU).
Their similar appearance suggests that ichthyosaurs and whales develop similar strategies to adapt to marine life – an example of convergent evolution.
Professor Schweitzer said: "They have many features common to live marine reptiles such as sea turtles, but we know the fossil record that they give a live birth, which is associated with warm blood. "
Co-author, Johan Lindgren, from Lund University in Sweden, told BBC News: "Blubber is finding marine mammals who live, but especially those who are adults of & # 39; the leather sea turtle. It's apparent that insulation is its main role in each of these animals. Leatherback is unique in many aspects.
"It has higher metabolic rates than typical reptiles, and has a series of measures for heat retention and control, and these allow adult leather bags to venture into water environments cold.
"Therefore, ichthyosaurs were able to control at least body temperature as well as leather, but it's hard to say if they were completely endothermic (warm bloody)."
The researchers noted that the flowers and skin continued on a well-preserved ichthyosaur specimen conducted by Urweltmuseum Hauff in Germany. It was discovered in the Holzmaden quarry, in the southwest of the country, which has produced many other fossils that have been well maintained by the Jurassic Period.
The fossil was the subject of a comprehensive analysis of a microscopic structure and a molecular composition.
"The body and body organs outline is obvious," said co-author Johan Lindgren, from Lund University in Sweden.
"Unbelievably, the fossil has to keep it so good that it is possible to observe individual cellular layers within its skin."
The researchers identified similar microscopy structures that were likely to have a pigment, and an internal organ thought that the animal was younger.
Blubber-like material included fragments of fatty acid molecules.
"This is the first first chemical evidence for warm blood in iththososaur, because blubber is a feature of warm blood animals," said Professor Schweitzer.
In order to provide additional support for this idea, researchers went to artificially mature in the gap of a modern gap, highlighting it to high temperatures and pressure – as it would be during the process of fossils.
The flower split "mature" porpoise that results in many features with the fossilized version.
Most reptiles today are cold blood, which means that the body temperature is determined by the warmth of their environment. Blubber's main function is an insulation to help marine mammals maintain high body temperature regardless of the ambient temperature of seawater.
In the case of the iththosaous skin, the camouflage pattern would have been a defense against Jurassic predators such as flying pterosaurs, ground attack, and pliosaurs (even more marine reptiles), which would have undergone aggression.
Dr Lindgren said: "Given the density of pigment cells, and the fact that they occur in the epidermis and dermis, we do not assume that ichthyosaurs have very dark dorsal (upper) skin, which Also what you see in many existing whales are deep divergent (such as ichthyosaurs) and an enterprise into cold regions (such as ichthyosaurs).
"Melanic (dark) colouration would benefit from ichthyosaurs as UV protection while on the surface of the sea, but it might also help ichthyosaurs to be reinforced as it happened in the leather sea turtle."
Losing scales and creating smooth skin would also help ichthyosaurs to move easier underwater.
Johan Lindgren said that the skin that is still flexible is that the specimen has to be fossilized so fast that organic molecules are caught in mineral and fossil parts.
"Soft tissues, such as skin, have even been considered as food (easily cut down) that the only way they can survive is through new mineral minerals, however, as it is. It seems that when these minerals are removed, some of the original organic remains, "explained Dr. Lindgren.
The results are published in Nature magazine.
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