User:Ashorocetus/sandbox/Dendroolithus
| Ashorocetus/sandbox/Dendroolithus Temporal range:
| |
|---|---|
| |
| Dendroolithus | |
Egg fossil classification 
| |
| Basic shell type: | †Dinosauroid-spherulitic |
| Oofamily: | †Dendroolithidae |
| Oogenus: | †Dendroolithus |
| Type oospecies | |
| Dendroolithus wangdianensis | |
| Oospecies | |
| |
Dendroolithus is an oogenus of Dendroolithid dinosaur egg native to China and Mongolia.[1][2] They can be up to 162 mm long and 130 mm wide.[3] These eggs may have been laid by a Therizinosaur, Sauropod, or Ornithopod.[4] The oospecies "D." shangtangensis was originally classified as Dendroolithus, however, it has since been moved to its own distinct oogenus, Similifaveoloolithus.[5]
Description[edit]
Dendroolithus are small to medium sized eggs with shapes from spherical to somewhat oval, ranging from 6 to 20 cm (2.4 to 7.9 inches) in diameter. The outside of the shell was covered with a rough but irregular ornamentation. Their eggshell structure is typical of Dendroolithidae: the shell units branch irregularly, somewhat like a tree (hence the name, which means "Tree stone egg"). They have a prolatocanaliculate pore system, which means that the pores in the eggshell have variable width. In Dendroolithus the pores connect together into a network.[2]
Oospecies[edit]
- D. dendriticus
- D. fengguangcunensis - Large, spherical eggs, ranging from 15 to 17 cm (5.9 to 6.7 in) in diameter, with a smooth surface and a 1.6 mm (0.063 in) thick shell. The shell units are tightly packed together.[6]
- D. furcatus
- D. hongzhaiziensis - this oospecies is similar to D. tumiaolingensis, with a similar oblate spheroid shape 14 cm (5.5 in) across and a smooth surface. The eggshell is 1.40 to 2.24 mm (0.055 to 0.088 in) thick. It is distinguished from D. tumiaolingensis in that the shell units in D. hongzhaiziensis are intertwined together, while in D. tumiaolingensis they are independent.[7]
- D. microporosus - a roughly spherical, thick-shelled Mongolian oospecies, is relatively small, measuring only 70 by 60 mm (2.8 by 2.4 in), with a shell typically between 2.0 and 2.7 mm (0.079 and 0.106 in) thick. It also has a smoother surface than the other oospecies.[8]
- D. sanlimiaoensis
- D. shuangtangensis - A Chinese oospecies, with an oblate shape measuring up to 13.5 cm (5.3 in) in diameter. The upper 5th of its eggshell consists of a layer of fusion of the eggshell units.[9]
- D. tumiaolingensis - this Chinese oospecies is 14.2 to 16.5 cm (5.6 to 6.5 in) across, with a smooth outer surface. Its eggshell is 1.84 to 2.04 mm (0.072 to 0.080 in) thick, about 1/4 of which is the mammillary layer. The known fossils have a distinctive oblate spheroid shape and are further distinguished by having finer branches of the eggshell units than other Dendroolithus oospecies. The fossils formerly assigned to Placoolithus cf. taoheensis may in fact belong to D. tumiaolingensis.[7]
- D. verrucarius - this Mongolian oospecies derives its name from the Latin verrucarius, meaning warty. It is distinctive for having a thick shell, up to 4.3 mm (0.17 in) thick, though it is typically between 2.6 and 3.3 mm (0.10 and 0.13 in). Complete eggs are unknown, but it was probably smaller D. wangdianensis, with an estimated diameter of 90–100 mm (3.5–3.9 in). It is distinctive for having a small secondary layer of shell units, comprising the out 1/5 to 1/7 of the shell.[8]
- D. wangdianensis - the type oospecies, these eggs are oval shaped, measuring 14.5–16.2 cm (5.7–6.4 in) long by 11–13 cm (4.3–5.1 in) wide. The shell is relatively thin, measuring only 1.7–2.1 mm (0.067–0.083 in) thick, about one third of which is the mammillary layer.[2]. Some specimens preserve remnants of the eggshell membrane on the inner surface of the shell.[10]
- D. xichuanensis - a Chinese oospecies, oval shaped with a smooth outer surface, measuring about 12–16 cm (4.7–6.3 in) in diameter. It is overall similar to D. wangdianensis, but differs in that its shell units branch further away from the mammillary layer than in D. wangdianensis.[11][12]
- D. zhaoyingensis
Paleobiology[edit]
History[edit]
Dendroolithus wangdianensis was first described in 1988 by Chinese paleontologists Zhao Zikui and Li Zuocong, based on two well preserved clutches discovered in Hubei. They erected a new family for these specimens, because they were clearly quite distinct from Elongatoolithidae, Spheroolithidae, and Faveoloolithidae.[10] In 1991, the Russian paleontologist Konstantin Mikhailov reported eggs possibly referable to Dendroolithus in Mongolia,[13] which he would later name D. varrucarius in 1994, at which time he also named a new oospecies, D. microporosus.[8] The oospecies D. hongzhaiziensis and D. tumiaolingensis were described by a group of Chinese paleontologists working for the China University of Geosciences, Wuhan. These specimens were discovered on an early investigation into fossils in the Qinglongshan region of Hubei.[7] One oospecies, "D." guoqingsiensis, named by Fang et al. in 2000, was reclassified as an oospecies of Parafaveoloolithus in 2010 by the Chinese paleontologist Wang Qiang.[14]
Distribution and Paleoecology[edit]
D. wangdianensis fossils are known from Wangdian village, Heshui, Anlu county, Hubei Province, part of the upper Cretaceous Gong-An-Zhai Formation.[10]
Both D. verrucarius and D. microporosus are known from the Gobi region of Mongolia. D. verrucarius is found in the lower part of the Nemegt Formation, and possibly the upper Barun Goyot Formation. D. microporosus is found in the Barun Goyot Formation.[8]
D. tumiaolingensis and D. hongzhaiziensis are both found in the late Cretaceous Gaogou Formation.[7]
References[edit]
- ^ Paleobiology Database
- ^ a b c Appendix II in Carpenter, K. 1999. Eggs, Nests, and Baby Dinosaurs: A Look at Dinosaur Reproduction (Life of the Past). Indiana University Press, Bloomington, Indiana.
- ^ Z. Zhao and Z. Li. 1988. A new structural type of the dinosaur eggs from Anlu County, Hubei Province. Vertebrata PalAsiatica 26(2):107-115
- ^ 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. JSTOR 4523773.
- ^ 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.
- ^ Fang, Xiaosi; Zhang, Zhijun; Zhang, Xianqiu; Lu, Liwu; Han, Yingjian; Li, Peixian (2005). "广东河源盆地蛋化石". Geological Bulletin of China. 24 (7): 682–686.
- ^ a b c d Zhou, Xiugao; ren, Youfu; Xu, Shiqiu; Guan, Kangnian (1998). "Dinosaur eggs of the Late Cretaceous from Qinglongshan region, Yunxian County, Hubei Province". Hubei Geology & Mineral Resources. 12 (3): 1–8.
- ^ a b c d Mikhailov, Konstantin (1994). "Eggs of sauropod and ornithopod dinosaurs from the Cretaceous deposits of Mongolia". Paleontological Journal. 28 (3): 141–159.
- ^ Fang, Xiaosi; Lu, Liwu; Jiang, Yang'en; Yang, Liangfeng (2003). "Cretaceous fossil eggs from the Tiantai basin of Zhejiang, with a discussion on the extinction of dinosaurs". Geological Bulletin of China (in Chinese). 22 (7): 512–520.
- ^ a b c Zhao, Zikui; Li, Zuocong (1988). "A new structural type of dinosaur eggs from Anlu County, Hubei Province" (PDF). Vertebrata PalAsiatica. 26 (2): 107–115.
- ^ Zhao, Hong; Zhao, Zikui (1998). "Dinosaur eggs from Xichuan Basin, Henan Province" (PDF). Vertebrata PalAsiatica. 10 (36): 4.
{{cite journal}}: More than one of|pages=and|page=specified (help) - ^ Liang, Xinquan; Wen, Shunv; Yang, Dongsheng; Zhou, Shiquan; Wu, Shichong (2009). "Dinosaur eggs and dinosaur egg-bearing deposits (Upper Cretaceous) of Henan Province, China: Occurrences, palaeoenvironments, taphonomy and preservation". Progress in Natural Science. 19 (11): 1587–1601. doi:doi.org/10.1016/j.pnsc.2009.06.012.
{{cite journal}}: Check|doi=value (help) - ^ Cite error: The named reference
Mikhailov 1991was invoked but never defined (see the help page). - ^ Zhang, S. K. (2010). "A parataxonomic revision of the Cretaceous faveoloolithid eggs of China" (PDF). Vertebrata PalAsiatica. 48 (3): 203–219. Retrieved 3 October 2015.
