A new kind of fossilized dinosaur skin may help sort out real dino hide fossils from skin-like features in rocks.
A new texture of dino skin fossil suggests a duck-billed dino was preserved in South Korea.
Micro-polygons on the fossil's scales help make the case for skin.
Some paleontologists remain skeptical about fossilized skin impressions.
A new kind of fossil dinosaur skin discovered in South Korea may help sort out the real dino hides from skin-like features in rocks which are nothing of the sort.
Two specimens of fossil dinosaur skin from Cretaceous Haman Formation in South Korea have been found in a pile of rocks blasted to construct a road. The find includes an entirely new type of skin texture.
At the same time, several types of sedimentary accidents that have nothing to do with dinosaurs, but which look very much like skin fossils, were discovered.
The new skin texture is what appears to "micro-polygons" within the impressions of reptilian scales, say the South Korean researchers, who have published their discovery in the upcoming September issue of the Journal of Asian Earth Sciences.
"Fossil skins with similar features to that found in the Haman Formation are interpreted to represent the skin of a hadrosaur or sauropod dinosaur," reports In Sung Paik, a geology professor at Pukyong National University in Busan, South Korea and lead author of the paper. "The development of micro-polygons..is a new feature of dinosaur skins, reported here for the first time."
Tracks of the same kinds of dinosaurs have also been found in the same formation of rocks, which may strengthen the connection, the researchers contend.
"Looking at their pictures I'd say yeah, looks like duck-billed dinosaur skin," said paleontologist Spencer Lucas of the New Mexico Museum of Natural History and Science, referring to the common name for hadrosaurs. "The problem is they don't have that clear association with bone."
In other words, without some actual dinosaur bones to associate with the skin impressions, there will always be good reason to be skeptical, explained Lucas, who has studied hadrosaur skin impressions from North America.
"They are probably right, but they are behind the eight ball from the moment they started" because they have no bones, Lucas told Discovery News.
This led to what Lucas says is the most important part of what Paik's team has done, said Lucas: They have looked closer at how easy it is to be fooled by false skin impressions.
"Experts in both dinosaur skin fossils and sedimentary structures can distinguish true skin impressions from inorganic sedimentary structures," In Sung Paik told Discovery News. "However, non-specialists can misidentify inorganic sedimentary structures as skin impressions."
Dinosaur skin impressions previously found in North America show scaly texture that is mimicked by polygonal cracks created by drying and shrinking of ancient mud or pitting of mud by ancient raindrops. The Haman specimens contain neat polygons as well, which they argue are dinosaur skin impressions because, among other things, the pattern is very regular with clear edges and grains of sand that are not stacked like those of flowing material.
Finally, there are those micro-polygons on one specimen.
The team also compares several false "skins" to bonafide dinosaur skins to try and make it clear which is which.
"It's a big subject" and a huge debate, says Lucas, regarding the fossilization of skins and other soft tissues. Which puts the South Koreans right in the thick of it.