Traces of bird-sized raptor dinosaur found in Jinju

The fossil footprints of the world’s smallest “raptor” dinosaur have been found in South Korea. Some of the dinosaurs included in the raptor family are “velociraptors,” the small theropod dinosaur known for their group hunting with remarkable intelligence and agility as depicted in the movie “Jurassic Park.” The official name of the dinosaur found this time is “Dromaeosaurus,” which means a swift running lizard.

A research team led by Kim Kyung-soo, a professor at the Department of Science Education of Chinju National University of Education, Lim Jong-deok, a researcher at the Cultural Heritage Administration, and Kim Dong-hee, a researcher from the National Science Museum of Korea, found 1.0-centimeter-long diminutive tracks of a mini dinosaur during their a joint research work with American, Spanish, Australian, and Chinese scientists from the lower Cretaceous excavations in Jinju Innovation City and discovered that the tracks belonged to the dromaeosaurus, the world’s smallest dinosaur the size of a sparrow, which has been released on the Scientific Reports, an online science journal, on Thursday.

In 2007, another 1-centimeter-long footprints were found in Namhae, South Gyeongsang Province, which belonged to a carnivore called minisauripus, but this is the first time that any traces of the raptor genus in such a small size have been found in South Korea.

The researchers worked on 18 U-shaped tracks found in the “Jinju Formation”, a stratum dating 110 million years back. U or V shaped footprints are peculiar to the raptor dinosaurs as they stand on their rear legs and use only two out of three hind toes. The remaining toe did not touch the ground as it was shaped like a sickle. Scientists presume that the third toe was used for hunting.

The footprints unearthed in Jinju are 1-centimeter-long and 0.4-centimeter-wide, the smallest size of all raptors’ tracks found so far. Previously, the smallest raptor found was a microraptor in the size of a crow, whose footprints are 2.5-centimeter-long. It is presumed that the dinosaur found this time was in the size of a sparrow. However, it remained unknown whether the footprints belonged to a fully grown or a baby dinosaur.

In either case, dinosaur tracks in such a small size are extremely rare to come by. “Traces that are 1-centimeter-long are very difficult to preserve and discover, and they are extremely rare in any country around the world,” said Kim Kyung-soo.

The sheer number of birds-sized dinosaurs is small, and their footprints rarely fossilize as they are easily eroded. The traces of baby dinosaurs are also very rare as they grow fast.


ashilla@donga.com