Jurassic large carnivorous dinosaurs “appear” in Chongqing main urban area
A researcher of No. 208 Geological Team of Geological Relics Protection Research Institute is drawing the dinosaur tracks on site. (Picture provided by Chongqing Municipal Bureau of Planning and Natural Resources and released by CQNEWS)
CHONGQING (CQNEWS) -- After some “chicken footprints” were found by rock climbers in Chongqing Gele Mountain National Forest Park last year, Chongqing Municipal Bureau of Planning and Natural Resources immediately organized a paleontologist team to investigate and research. Recently, the latest research result has been publicized in the famous British SCI journal Historical Biology in the form of a research paper. The research has confirmed that the dinosaur tracks belong to Kayentapus, formed about 190 million years ago, and they can be classified into the type species, Kayentapus hopii, because they are the best preserved Jurassic Kayentapus groups.
The tracks are located on two quartz sandstone surfaces about 3 meters apart, and a total of 46 tridactyl theropod tracks are found. Among them, the first-layer surface includes 7 trackways consisting of 32 tracks in total, and another 12 separate tracks; the second-layer surface includes 2 separate tracks in total. The average length of the tracks in the first-layer 7 trackways is 24.1 cm, with the longest one of 35 cm and the shortest one of 16 cm. According to the measured relative stride length of the tracks, the experts speculated that the tracks were made by large and medium theropod dinosaurs and the “trackmakers” were trotting at that time.
Characteristics of Kayentapus in Gele Mountain. (Picture provided by Chongqing Municipal Bureau of Planning and Natural Resources and released by CQNEWS)
The Kayentapus originally referred to the generic name for tracks of a large (about 35 cm) tridactyl bipedal theropod dinosaur, which was first found in the Lower Jurassic Kayenta Formation of Arizona, USA. The Kayentapus is characterized by that no big toe trace is reserved, but the metatarsophalangeal pad trace of the fourth toe is reserved and completely separated from the rest traces.
The Kayentapus tracks in China are mainly distributed in the Lower Jurassic Kayenta Formation of Lufeng and Jinning in Yunnan Province, Panzhihua and Xichang in Sichuan Province and Zizhou in Shaanxi Province. In North America, the Kayentapus “trackmakers” were Theropod Dilophosaurus or Tetanurae living in the early Jurassic period worldwide, which were one of the earliest large carnivorous dinosaurs. According to Dai Hui, senior engineer of No. 208 Geological Team of Chongqing Geological Relics Protection Research Institute, the Kayentapus “trackmaker” in southwest China might be Sinosaurus. The Sinosaurus is a kind of fierce large carnivorous dinosaur with two coronae on its head, a length about 5.6 m and the weight up to half a ton.
Scene picture and sketch of dinosaur trackways in Chongqing Gele Mountain National Forest Park. (Picture provided by Chongqing Municipal Bureau of Planning and Natural Resources and released by CQNEWS)
The Kayentapus is widely distributed worldwide, but exact tracks of Kayentapus hopii have never been found in Asia before. According to Dai Hui, the discovery of rich Kayentapus tracks in China and even Asia also further proves that the Jurassic dinosaur tracks in Asia and even all over the world were made by theropod dinosaurs, and the track pattern types show consistent diversity, which is of great significance for studying the distribution and evolution of early Jurassic dinosaur fauna in China. (Translated by Huang Juan, Fathom Language Limited)