New type of dinosaur eggs found from Early Cretaceous of Gansu Province, China

April 5, 2016, Chinese Academy of Sciences
New type of dinosaur eggs found from Early Cretaceous of Gansu Province, China
Fig.1 Eggshells of Polyclonoolithus yangjiagouensis (Image by XIE Junfang

Dinosaur eggs from the Lower Cretaceous are worldwide rare as compared to those from Upper Cretaceous deposits. In China, they were only reported in Liaoning Province. In a paper published in the latest issue of Vertebrata PalAsiatica, paleontologists described a new type of dinosaur eggs from the Lower Cretaceous Hekou Group in the Lanzhou-Minhe Basin, northwestern China, and established a new oogenus and a new oospecies, within a new oofamily. 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 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.

The new oospecies, Polyclonoolithus yangjiagouensis, can be distinguished from other known dinosaur eggs by the combination of micro-features, such as branched eggshell units lacking a compact layer near the outer surface, interlocking or isolated multi-angular eggshell units as viewed in tangential sections, and irregular pore canals. Researchers attributed it to a new oofamily, Polyclonoolithidae.

Fig.2 Eggshell microstructure of Polyclonoolithus yangjiagouensis. Credit: XIE Junfang
"Dinosaur eggs from China largely come from the Late Cretaceous deposits, with occasional reports from the Early Cretaceous in Liaoning Province, northeastern China. The new discovery expands the geological and geographical distribution of the fossil record of in China and may reveal the origin of eggshell microstructures of spheroolithid eggs", said Dr. ZHANG Shukang, corresponding author of the study at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences.

"The new oofamily Polyclonoolithidae shares a close relationship with the oofamilies Dendroolithidae, Dictyoolithidae and Similifaveoloolithidae. It may represents a more basic type of dinosaur egg, which had been extinct in Late Cretaceous. The discovery of this new oofamily possibly indicates there is an unknown dinosaur egg fauna preserved in the Early Cretaceous deposits of China. It has the same eggshell formation mechanism as that of dendroolithid, dictyoolithid and faveoloolithid eggs, and shows some relationships with spheroolithid eggs. It may reveal the origin of eggshell microstructures of spheroolithid eggs", said XIE Junfang, lead author of the study, Zhejiang Museum of Natural History, Hangzhou.

Explore further: New dinosaur egg with avian egg shape discovered from the Upper Cretaceous of Zhejiang Province, China

More information: New Type of Dinosaur Eggs Found from Early Cretaceous of Gansu Province, China.
www.ivpp.cas.cn/cbw/gjzdwxb/xb … 0229563042622198.pdf

Related Stories

New forms of dinosaur eggs (Dictyoolithids) found

February 5, 2013

Paleontologists from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, collected some dinosaur eggs of the oofamily Dictyoolithidae from the Upper Cretaceous Chichengshan ...

Paleontologists discover new oofamily of dinosaur egg

October 10, 2012

Paleontologists from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, found more than a dozen eggs from the lower member of the Late Cretaceous Chichengshan Formation in ...

Polacanthine ankylosaur dinosaur first discovered in Asia

December 23, 2013

In a study published in the latest issue of Vertebrata PalAsiatica 51(4), Dr. YOU Hai-Lu, Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, and his collaborators from China University ...

Recommended for you

Frog choruses inspire wireless sensor networks

January 21, 2019

If you've ever camped by a pond, you know frogs make a racket at night; but what you might not know is how functional and regulated their choruses really are. Frogs communicate with sound, and amid their ruckus is an internally ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.