326 — New ootype prismatoolithids from the Late Cretaceous, Laiyang Basin and its significance

Growing up, I was always on the hunt for fossils in northern New Jersey. I never found any.

Oh, to be a small dinosaur-obsessed child in Shandong, China!

The Laiyang Basin in Shandong Province is a fossil-rich area where vertebrate fossils and fossilized eggs (ootypes) are common. In fact, the ontology used today to categorize dinosaur eggs was designed in the 70s in response to the number of eggs found in Laiyang.

This paper focuses on prismatoolithids — fossil eggs most likely laid by Ornithoscelidae (ornithopods and theropods).

One of the most incedible things about ootypes is that the microstructure of the eggshell is preserved, which tells us a great deal about evolution (when did eggshell features arise?), development (how much parental care was necessary? And of what type?), and the ways in which baby dinosaurs matured.

The cone layer (the innermost layer of the shell unit) of one particular shell demonstrates that this type of dinosaur egg had more space in between individual shell units, and that same cone layer took up a much larger fraction of the total shell thickness when compared to other shells from similar ootypes.

This speciment increases the diversity of eggs found in Laiyang, and demonstrates that primatoolithids roamed a greater area of China than previously proven.