Spheroolithid dinosaur eggs from Cretaceous of Zhejiang Province, China.

[Ben Creisler <bcreisler@gmail.com>]

From: Ben Creisler
bcreisler@gmail.com


A new online paper:


Daniel E. Barta, Krista M. Brundridge, Jasmine A. Croghan, Frankie D.
Jackson, David J. Varricchio, Xingsheng Jin & Ashley W. Poust (2013)
Eggs and clutches of the Spheroolithidae from the Cretaceous Tiantai
basin, Zhejiang Province, China.
Historical Biology (advance online publication)
DOI:10.1080/08912963.2013.792811
http://www.tandfonline.com/doi/full/10.1080/08912963.2013.792811#.UZ2Pf7W1FcQ

Numerous discoveries in the Tiantai basin of Zhejiang Province, China,
enrich our understanding of the parataxonomy, paleobiology and
taphonomic histories of fossil eggs from a diverse array of Cretaceous
oofamilies. We describe the most abundant of these egg types
catalogued in the Zhejiang Museum of Natural History, Spheroolithus
cf. zhangtoucaoensis (oofamily Spheroolithidae). Scanning electron
microscopy, here utilised for the first time on Spheroolithus eggs
from Tiantai, and petrographic microscopy reveal 0.81–1.37-mm thick
eggshell composed of a single structural layer of calcite with
slightly flaring shell units, irregular pores, horizontal accretion
lines and a sweeping extinction pattern under crossed polars. This
contradicts previous reports of the presence of two structural layers
in Tiantai Spheroolithus. Clutches consist of 2–13 eggs arranged in an
irregular, single-layered pattern. As these eggs are among the oldest
Asian examples of Spheroolithus currently known, they may shed light
on the early evolution of this oogenus. This study establishes the
definitive presence of the Spheroolithidae in the Tiantai basin,
contra recent reports, and provides the framework for ongoing
examination of egg diversity and taphonomy in the Tiantai basin.