Scientists have described the smallest non-avian dinosaur eggs known to date.  The eggs, the smallest of which measures just 2.9 centimetres in length were probably laid by a small theropod.  The researchers have erected a new ootaxon Minioolithus ganzhouensis. This discovery increases the diversity of dinosaur eggs in the Late Cretaceous and is significant for our understanding of the evolution of theropods.  Everything Dinosaur contacted one of the authors of the scientific paper and we were emailed an image showing this remarkable dinosaur fossil.

Minioolithus ganzhouensis the smallest non-avian dinosaur eggs discovered to date. The fossil which represents a clutch of six, tiny theropod eggs was discovered at a construction site in Ganzhou (south-eastern China). Picture credit: Shukang Zhang (IVPP).

Picture credit: Shukang Zhang (IVPP)

Minioolithus ganzhouensis

The Upper Cretaceous Ganzhou Basin exposures located in Jiangxi Province have yielded exquisite fossils of dinosaur nests, eggs and embryos. Most of these egg fossils represent oviraptorosaurs. However, troodontid, hadrosaur and potential dromaeosaurid egg fossils have also been reported. Scientists have been able to learn about dinosaur nesting and reproductive behaviours. Intriguingly, all the eggs known from these deposits were relatively large. Writing in the academic journal “Historical Biology”, the researchers describe a partial clutch with six complete small eggs. The fossil material comes from the Tangbian Formation and the eggs are thought to be around eighty million years old.

China has provided a wealth of dinosaur egg fossils.  Furthermore, the theropod egg fossils have helped to shed light on the relationship between avian and non-avian dinosaurs.  For example, a remarkable dinosaur egg fossil from southern China demonstrated the “tucking” position in an embryo. This posture is seen in the embryos of modern birds. It is a behaviour controlled by the central nervous system and it is critical for hatching success.

To read more about the remarkable theropod embryo fossil: Exquisitely Preserved Theropod Embryo Found Inside Egg.

Mike from Everything Dinosaur commented:

“This is a remarkable fossil find.  Our thanks to the research team for sharing the image with us.  Discoveries such as this are helping palaeontologists to learn more about the remarkable links between today’s birds and their theropod ancestors.”

Everything Dinosaur acknowledges the assistance of one of the scientific paper’s authors in the compilation of this article.

The scientific paper: “The smallest known complete dinosaur fossil eggs from the Upper Cretaceous of South China” by Rui Wu, Fasheng Lou, Juan Yu, Yu Xue, Shukang Zhang, Ling Yang, Wenjiang Qiu, Huimin Wang and Fenglu Han published in Historical Biology.

The award-winning Everything Dinosaur website: Dinosaur and Prehistoric Animal Models.