Paradictyoolithus is an oogenus of dictyoolithiddinosaur egg from the Zhejiang Province, China. They are nearly spherical eggs, measuring up to 13.9 cm (5.5 in) in diameter, and have a thin eggshell. Their shells are made up of three or four superimposed layers of eggshell units. The two known oospecies are distinguished mainly by their pore structure.[1]
Prior to 2013, descriptions of dictyoolithids were brief due to the scarcity of material. However, in 2013 the Chinese paleontologists Wang Qiang, Zhao Zi-Kui, Wang Xiao-Lin, Zhang Shu-Kang from the Chinese Academy of Sciences working together with Jiang Yan-Gen from the Tiantai Bureau of Land and Resources of Zhejiang Province, described several new dictyoolithid specimens, including both oospecies of Paradictyoolithus.[1]
Descriptionedit
Paradictyoolithus eggs are roughly spherical, measuring 10.8–13.9 cm (4.3–5.5 in) in diameter. Their eggshell is thin, measuring only 1.8 to 2.2 mm thick (compared to 2.5 to 2.8 mm in its close relative, Dictyoolithus). The shell consists of three or four layers of superimposed eggshell units. A radial cross section of the eggshell reveals the net-like (or reticulate) arrangement of the eggshell units, typical of dictyoolithid eggs. The shell units are slender and irregularly shaped.[1]
Paradictyoolithus contains two oospecies: P. zhuangqianensis and P. xiaxishanensis. The two oospecies are primarily distinguished by their pore structure. P. zhuangqianensis has pores which all connect to each other in irregular patterns; the walls of the pores are separated into disconnected blocks. P. xiaxishanensis, on the other hand, has well-separated pore canals which look like a honeycomb in cross-section. Also, P. zhuangqianensis is slightly larger than P. xiaxishanensis, but has a thinner shell.[1]
A fossilized egg clutch containing six eggs and an egg impression reveals that P. xiaxishanensis eggs were arranged irregularly in their nest.[1] The only known clutch of P. zhuangqiensis is not well enough preserved to determine how the nest was organized.[1]
Referencesedit
^ abcdefgWang, Qiang; Zhao, Zikui; Wang, Xiaolin; Zhang, Shukang; Jiang, Yan'gen (2013). "New forms of dictyoolithids from the Tiantai Basin, Zhekiang Province of China and a parataxonomic revision of dictyoolithids" (PDF). Vertebrata PalAsiatica. 51: 43–54.
^Huaiyu He, Xiaolin Wang, Qiang Wang, Shunxing Jiang, Xin Cheng, Jialiang Zhang, Zhonghe Zhou, Zikui Zhao, Yangen Jiang, Fangming Yu, Chenglong Deng, Jinhui Yang, 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.
December 15, 2023
paradictyoolithus, oogenus, dictyoolithid, dinosaur, from, zhejiang, province, china, they, nearly, spherical, eggs, measuring, diameter, have, thin, eggshell, their, shells, made, three, four, superimposed, layers, eggshell, units, known, oospecies, distingui. Paradictyoolithus is an oogenus of dictyoolithid dinosaur egg from the Zhejiang Province China They are nearly spherical eggs measuring up to 13 9 cm 5 5 in in diameter and have a thin eggshell Their shells are made up of three or four superimposed layers of eggshell units The two known oospecies are distinguished mainly by their pore structure 1 ParadictyoolithusTemporal range Upper Cretaceous PreꞒ Ꞓ O S D C P T J K Pg N Egg fossil classificationBasic shell type Dinosauroid spheruliticOofamily DictyoolithidaeOogenus ParadictyoolithusWang et al 2013Oospecies P zhuangqianensis Wang et al 2013 type P xiaxishanensis Wang et al 2013 Contents 1 Distribution 2 Discovery 3 Description 4 ReferencesDistribution editBoth Paradictyoolithus oospecies are from the Chichengshan Formation in Tiantai County Zhejiang China 1 This formation was determined to be 91 to 94 million years old early Upper Cretaceous by Uranium lead dating 2 Discovery editPrior to 2013 descriptions of dictyoolithids were brief due to the scarcity of material However in 2013 the Chinese paleontologists Wang Qiang Zhao Zi Kui Wang Xiao Lin Zhang Shu Kang from the Chinese Academy of Sciences working together with Jiang Yan Gen from the Tiantai Bureau of Land and Resources of Zhejiang Province described several new dictyoolithid specimens including both oospecies of Paradictyoolithus 1 Description editParadictyoolithus eggs are roughly spherical measuring 10 8 13 9 cm 4 3 5 5 in in diameter Their eggshell is thin measuring only 1 8 to 2 2 mm thick compared to 2 5 to 2 8 mm in its close relative Dictyoolithus The shell consists of three or four layers of superimposed eggshell units A radial cross section of the eggshell reveals the net like or reticulate arrangement of the eggshell units typical of dictyoolithid eggs The shell units are slender and irregularly shaped 1 Paradictyoolithus contains two oospecies P zhuangqianensis and P xiaxishanensis The two oospecies are primarily distinguished by their pore structure P zhuangqianensis has pores which all connect to each other in irregular patterns the walls of the pores are separated into disconnected blocks P xiaxishanensis on the other hand has well separated pore canals which look like a honeycomb in cross section Also P zhuangqianensis is slightly larger than P xiaxishanensis but has a thinner shell 1 A fossilized egg clutch containing six eggs and an egg impression reveals that P xiaxishanensis eggs were arranged irregularly in their nest 1 The only known clutch of P zhuangqiensis is not well enough preserved to determine how the nest was organized 1 References edit a b c d e f g Wang Qiang Zhao Zikui Wang Xiaolin Zhang Shukang Jiang Yan gen 2013 New forms of dictyoolithids from the Tiantai Basin Zhekiang Province of China and a parataxonomic revision of dictyoolithids PDF Vertebrata PalAsiatica 51 43 54 Huaiyu He Xiaolin Wang Qiang Wang Shunxing Jiang Xin Cheng Jialiang Zhang Zhonghe Zhou Zikui Zhao Yangen Jiang Fangming Yu Chenglong Deng Jinhui Yang 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 Retrieved from https en wikipedia org w index php title Paradictyoolithus amp oldid 1090680563, wikipedia, wiki, book, books, library,
