AsianScientist (Apr. 13, 2016) – Dinosaur eggs from the Lower Cretaceous are rare compared to those from Upper Cretaceous deposits, and in China, they were only previously found in Liaoning Province. Now, Chinese paleontologists have discovered of a new type of dinosaur egg from the Lower Cretaceous Hekou Group in the Lanzhou-Minhe Basin, northwestern China.
This finding has important implications for understanding the diversity and the geological and geographical distribution of Early Cretaceous dinosaur eggs in China, as well as the evolution of dinosaur eggshell structure. The paper was published in Vertebrata PalAsiatica.
The new specimen is an incomplete and highly fragmented egg, discovered in outcrops near the border of Yongjing and Lintao counties, in the central region of the Lower Cretaceous Lanzhou-Minhe Basin. The Lanzhou-Minhe Basin is located on the border of Gansu and Qinghai provinces, and represents a typical Mesozoic-Cenozoic intracontinental rift basin in western China.
The Early Cretaceous outcrops in Gansu Province have yielded numerous dinosaur skeleton remains and tracks, but dinosaur eggs have not been reported so far.
This new egg species, Polyclonoolithus yangjiagouensis, can be distinguished from other known dinosaur eggs by its unique combination of eggshell micro-features. Researchers have attributed it to a new dinosaur egg family, Polyclonoolithidae.
“Dinosaur eggs from China largely come from the Late Cretaceous deposits, with occasional reports from the Early Cretaceous in Liaoning Province, northeastern China,” said corresponding author, Dr. Zhang Shukang from the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences.
According to Zhang, the new discovery expands the geological and geographical distribution of the fossil record of dinosaur eggs in China, and may reveal the origin of eggshell microstructures of spheroolithid eggs.
“[The new egg] may represent a more basic type of dinosaur egg, which had been extinct in Late Cretaceous,” said lead author of the study, Xie Junfang, from the Zhejiang Museum of Natural History, Hangzhou.
Xie added that the discovery of this new dinosaur egg family possibly indicates there is an unknown dinosaur egg fauna preserved in the Early Cretaceous deposits of China.
The article can be found at: Xie et al. (2016) A new type of dinosaur eggs from Early Cretaceous of Gansu Province, China.
———
Source: Chinese Academy of Sciences; Photo: OakleyOriginals/Flickr/CC.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.
