''Hemifaveoloolithus'' is an

oogenus Egg fossils are the fossilized remains of eggs laid by ancient animals. As evidence of the physiological processes of an animal, egg fossils are considered a type of trace fossil. Under rare circumstances a fossil egg may preserve the remains ...

of fossil

dinosaur egg Dinosaur eggs are the organic vessels in which a dinosaurs, dinosaur embryo develops. When the first scientifically documented remains of non-avian dinosaurs were being described in England during the 1820s, it was presumed that dinosaurs had la ...

from the Tiantai basin in

Zhejiang Province ) , translit_lang1_type2 = , translit_lang1_info2 = ( Hangzhounese) ( Ningbonese) (Wenzhounese) , image_skyline = 玉甑峰全貌 - panoramio.jpg , image_caption = View of the Yandang Mountains , image_map = Zhejiang i ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. 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 The year marked the start of a Arab Spring, series of protests and revolutions throughout the Arab world advocating for democracy, reform, and economic recovery, later leading to the depositions of world leaders in Tunisia, Egypt, and Yemen ...

, paleontologists at the Institute of Vertebrate Paleontology and Paleoanthropology,

Chinese Academy of Sciences The Chinese Academy of Sciences (CAS; ) is the national academy for natural sciences and the highest consultancy for science and technology of the People's Republic of China. It is the world's largest research organization, with 106 research i ...

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 Tiantai County ( Tai-chow dialect: T'in-t'e yön; ) is located in Taizhou, Zhejiang, People's Republic of China. Residents mainly speak the Tiantai dialect. The county is noted for its scenic Mount Tiantai, which is also an important Tiantai ...

Zhejiang ) , translit_lang1_type2 = , translit_lang1_info2 = ( Hangzhounese) ( Ningbonese) (Wenzhounese) , image_skyline = 玉甑峰全貌 - panoramio.jpg , image_caption = View of the Yandang Mountains , image_map = Zhejiang i ...

. It is found in the

Upper Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cret ...

Chichengshan Formation, which was dated to be 91–94 million years old (during the

Turonian The Turonian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the second age (geology), age in the Late Cretaceous epoch (geology), Epoch, or a stage (stratigraphy), stage in the Upper Cretaceous series (stratigraphy), ...

) 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 In geometry, the tangent line (or simply tangent) to a plane curve at a given point is, intuitively, the straight line that "just touches" the curve at that point. Leibniz defined it as the line through a pair of infinitely close points on ...

cross-section a

honeycomb A honeycomb is a mass of Triangular prismatic honeycomb#Hexagonal prismatic honeycomb, hexagonal prismatic cells built from beeswax by honey bees in their beehive, nests to contain their brood (eggs, larvae, and pupae) and stores of honey and pol ...

-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

tuatara The tuatara (''Sphenodon punctatus'') is a species of reptile endemic to New Zealand. Despite its close resemblance to lizards, it is actually the only extant member of a distinct lineage, the previously highly diverse order Rhynchocephal ...

References

{{Taxonbar, from=Q22286542 Fossil parataxa described in 2011 Dinosaur reproduction