During the early Cretaceous, a small a two-legged dinosaur went after a rain over a section of fine-grained mud. The resulting footprints were carved in stone, but unlike other fossilized dinosaur tracks, these 120 million year old fossils show skin prints over the entire footprint, which is considered an unprecedented discovery.
Fossil footprints of dinosaurs are quite often the paleontological report, but only 1 percent of these traces show skin evidence. Of these, no skin has yet been detected over the entire footprint.
A new study published in Scientific Reports is "the first report for every skin-trace dinosaur that covers all footprints and footprints in a driveway," say the authors of the new paper. The impressions of a small two-legged dinosaur Minisauripus represent the "highest resolution of details recorded so far for dinosaur skin prints," noted the researchers, a team led by Kyung-Soo Kim of the Chinju National University of South Korea Education. The name Minisauripus is not used to describe a specific type of dinosaur, but is an Ichnotaxon, a name that categorizes various trace fossils such as footprints.
These incredible footprints were drawn from the Jinju Formation of Korea and are embedded on a slab of very fine gray sandstone with a thin stone embedded layer of black mudstone the top. The new paper describes four different tracks along a single path and an isolated fifth track from an unconnected plate. These surfaces were followed on clear acetate film, photographed at a low angle and measured to the nearest millimeter.
Each footprint is only about 2.5 cm long, but all contain perfectly preserved skin marks. With an estimated age of between 120 million and 112 million years, they are now the oldest Minisauripus traces in the fossil record.
Due to special environmental conditions, the footprint could appear without smudging. The little Dino walked over a thin layer of fine mud, which resembled "just a millimeter thick layer of fresh paint". Martin Lockley, a paleontologist at the University of Colorado Denver and co-author of the new newspaper, said in a statement. This proved to be the perfect medium for capturing the skin texture of the animal. In addition, the sticky surface prevented the dinosaur from sliding or slipping on the surface, ruining the integrity of the print.
In fact, the level of detail of these impressions is nothing out of the ordinary. and it's hard to believe they were made that long ago. Arrays of small scales, each less than half a millimeter wide, cover the entire surface of the dinosaur's small feet. The tiny scale marks, called polygons in the new paper, work together like woven fabric. The researchers said that the pattern resembles the pattern seen in feathered chalk birds from China, but the shape of their feet is very different. The patterns are similar to those left in the footprints of larger dinosaurs such as the Brontosaurus, but are much smaller than these. The "size of the polygons in the skin ornament is proportional to the track size," the authors wrote in the newspaper.
Based on the stride length and size of the footprints, the authors estimate a body length of 28.4 centimeters (11.2 inches) for that particular person. The dinosaur made long strides as it moved quickly across the muddy surface at speeds of 2.5 meters per second. The walking speed of humans is about 1.4 meters per second or about 3.1 miles per hour.
An interesting feature of the new prints is how the skin of the dinosaur extends between the toes. "The looseness and flexibility of the skin may have contributed to its spreading in contact with the [mud] so as not to delay the fine traces of skin when they were registered," write the authors of the study.
Another nice aspect of the discovery is that the researchers were able to detect impressions of raindrops in the fossilized mud, allowing them to perform some Cretaceous meteorology, as stated in the statement by UC Denver:
The evidence shows That just before the tracks were made, there had been a shower of rain that left impressions of water droplets. At one point, the dinosaur had stepped on a fresh raindrop mark, and it was proved that rain came first, and the dinosaur step came second. All this delicate evidence has been preserved by gently covering it with finer mud.
Paleontologist Eugenia Gold of Suffolk University in Boston said the information gained from these impressions makes our interpretations of dinosaur skin more complete.
This ichnotaxone was previously found in China and Korea. These new tracks show skin impressions across the entire footprint, which is very rare and an exciting find, "said Gold, who was not involved in the new study, in an email to Gizmodo. "Moreover, the tracks are older than the other known traces of this ichnotaxon, indicating that this species was about 10 to 20 million years old, as we thought before."
An incredible discovery with certainty and an outstanding demonstration of how fossils are presented Other than bones can shed new light on these ancient secrets.
Correction: In an earlier version of this article, Minisauripus was falsely referred to as a dinosaur species, although it is actually an ichnotaxone, the name of an unmistakable trace fossil. We regret the mistake. Thanks to the commentator Zach Miller for this note.