Hemifaveoloolithus

''Hemifaveoloolithus'' is an oogenus of fossil dinosaur egg from the Tiantai basin in Zhejiang Province, China. It is a faveoloolithid, having spherical eggs roughly 13 cm in diameter. The shell is distinctive for being composed of four or five superimposed layers of shell units, and the honeycomb-like arrangement of pore canals.Wang Qiang, Zhao Zi-kui, Wang Xiao-lin, and Jiang Yan-gen. (2011)
New ootypes of dinosaur eggs from the Late Cretaceous in Tiantai Basin, Zhejiang Province, China.
''Vertebrata PalAsiatica'' 49(4):446–449.

History

During the 21st century, a great diversity of fossil eggs have been described from the Tiantai Basin. In 2011, paleontologists at the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences Wang Qiang, Zhao Zikui, and Wang Xiaolin teamed up with Jiang Yan'gen from the Tiantai Bureau of Land and Resources of Zhejiang Province to report the discovery of several new ootaxa at Tiantai, including ''Hemifaveoloolithus''.

Distribution

''Hemifaveoloolithus'' is one of many ootaxa known from Tiantai County in Zhejiang. It is found in the Upper Cretaceous Chichengshan Formation, which was dated to be 91–94 million years old (during the Turonian) by using U-Pb dating.Huaiyu He, Xiaolin Wang, Qiang Wang, Shunxing Jiang, Xin Cheng, Jialiang Zhang, Zhonghe Zhou, Zikui Zhao, Yangen Jiang, Fangming Yu, Chenglong Deng, Jinhui Yang, and Rixiang Zhu (2013).
SIMS zircon U–Pb dating of the Late Cretaceous dinosaur egg-bearing red deposits in the Tiantai Basin, southeastern China.
''Journal of Asian Earth Sciences,'' 62, 654–661.

Description

''Hemifaveoloolithus'' fossils are limited to a single incomplete nest with ten preserved eggs. The eggs are roughly spherical, measuring long by wide.Zou S.L, Wang Q., and Wang X.L. (2013)
A new oospecies of parafaveoloolithids from the Pingxiang Basin, Jiangxi Province of China
" ''Vertebrata PalAsiatica''. 51(2):102–106. Its eggshell is 1.60 mm thick. Like dictyoolithids and other faveoloolithids,Z.-K. Zhao. (1994) "Dinosaur eggs in China:On the structure and evolution of eggshells." In K. Carpenter, K. F. Hirsch, and J. R. Horner (eds.), ''Dinosaur Eggs and Babies,'' Cambridge University Press, Cambridge. Cambridge. pp. 184–203. its shell is composed of multiple superimposed layers of irregular eggshell units. ''H. muyushanensis'' is also notable for the high density of pores in its eggshell, about 50 per square millimeter, which give its tangential cross-section a honeycomb-like appearance.

Paleobiology

It is generally uncertain what type of dinosaurs laid faveoloolithid eggs, though they are conjectured to have been laid by sauropods.Tanaka, K., Zelenitsky, D. K., & Therrien, F. (2015)
Eggshell Porosity Provides Insight on Evolution of Nesting in Dinosaurs.
'' PLoS ONE'', 10(11), e0142829. Unlike most dinosaur eggs, where the shell membrane and the calcareous eggshell form sequentially, in dictyoolithids and faveoloolithids (including ''Hemifaveoloolithus'') the membrane and shell would develop simultaneously, comparable to eggs of modern tuataras.

References

{{Taxonbar, from=Q22286542

Fossil parataxa described in 2011
Dinosaur reproduction