Phaceloolithusis anoogenusofdinosaur eggfound in theFenshui'ao Formationof theDongtingBasin of theHunan ProvinceofChina.The eggs have a subspherical shape, measuring up to 168 mm on the long axis, and having a very thin shell.[1][2]
| Phaceloolithus Temporal range:
| |
|---|---|
Egg fossil classification
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| Basic shell type: | †Dinosauroid-spherulitic |
| Oofamily: | †Phaceloolithidae Zeng & Zhang, 1979 |
| Oogenus: | †Phaceloolithus Zeng & Zhang, 1979 |
| Oospecies | |
Distribution
editPhaceloolithusis found at the Dongting Basin in Hunan. They are dated, on the basis of other fossil eggs,ostracods(seed shrimp), andcharophytes(algae) found at the same site, to thelate Cretaceous.[1]
Description
editPhaceloolithusis nearly spherical, measuring 167–168 mm long and 140–150 mm across. The eggshell is very thin, measuring from 0.5 to 0.7 mm thick.[1]Like most other non-aviandinosaur eggs,[3]Phaceloolithus's shell is stratified into two layers: the prismatic layer on the outside, and the mammillary layer on the inside.[1]The mammillae are compressed into groups of two or three, and the pore canals are well-developed.[1]
History
editPhaceloolithuswas first described as the sole species of the oofamily Phaceloolithidae in1979by Chinese paleontologists Zeng Demin and Zhang Jin gian, following its discovery in the Dongting basin ofHunan.[1]
Parataxonomy
editWhilePhaceloolithushas always been considered an oospecies of Phaceloolithidae, there is dispute about whether or not this oofamily is synonymous with the later-namedDendroolithidae.The oofamilies were first synonymized by Fanget al.in2003.[4]This position was supported by Ribeiroet al.in2014,[5]but other authors have considered the two oofamilies distinct,[6][7]and in his master's thesis, Daniel Barta argued against synonymy because the brevity of the description of Phaceloolithidae makes any further referrals to that oofamily uncertain.[8]If the synonymy is correct, thenPhaceloolithuswould be a sister taxon toDendroolithusandParadendroolithus.If not, thenPhaceloolithuswould be thesole oogenusof Phaceloolithus.[9]
See also
edit
References
edit- ^abcdefD. Zeng and J. Zhang. (1979). "On the dinosaurian eggs from the western Dongting Basin, Hunan".Vertebrata PalAsiatica17(2):131–136
- ^Carpenter, K. (1999).Eggs, Nests, and Baby Dinosaurs: A Look at Dinosaur Reproduction(Life of the Past). Indiana University Press, Bloomington, Indiana.
- ^Laura E. Wilson, Karen Chin, Frankie D. Jackson, and Emily S. Bray. (2012). "Fossil eggshell: Fragments from the past"UCMP's online fossil egg exhibit.
- ^Fang, Xiao-si, et al. "Cretaceous fossil eggs from the Tiantai basin of Zhe gian g, with a discussion on the extinction of dinosaurs."Geological Bulletin of China22.7 (2003): 1–24.
- ^Ribeiro, V., Mateus, O., Holwerda, F., Araújo, R., & Castanhinha, R. (2014). "Two new theropod egg sites from the Late Jurassic Lourinhã Formation, Portugal."Historical Biology,26(2), 206–217.
- ^Konstantin E. Mikhailov, Emily S. Bray & Karl E. Hirsch (1996). "Parataxonomy of fossil egg remains (Veterovata): basic principles and applications".Journal of Vertebrate Paleontology.16(4): 763–769.doi:10.1080/02724634.1996.10011364.JSTOR4523773.
- ^Barta, D. E., Brundridge, K. M., Croghan, J. A., Jackson, F. D., Varricchio, D. J., Jin, X., & Poust, A. W. (2014). "Eggs and clutches of the Spheroolithidae from the Cretaceous Tiantai basin, Zhe gian g Province, China."Historical Biology,26(2), 183–194.
- ^Barta, D. E. (2014). "A phylogenetic approach to understanding dinosaur egg diversity and the evolution of reproductive traits within Dinosauria" (Master's thesis, Montana State University-Bozeman, College of Letters & Science).
- ^Fang Xiao-si, Yue Zhao, Ling Hong. (2009). "Gần mười lăm năm qua trứng hoá thạch nghiên cứu tình hình chung [Review of the Past 15 years’ Research on Fossil Eggs in China]". Địa cầu học báo, 30(4), 523–542.