Coralloidoolithusis anoogenusofdinosaur eggfrom the Tiantai Basin inZhejiang Province,containing a single known oospeciesC. shizuiwanensis.Formerly, it was classified in the oogenusParaspheroolithus;however, it was considered sufficiently different to be classified in its own genus.C. shizuiwanensisis similar toStalicoolithus,leading to their classification in the same family,Stalicoolithidae.[1]
| Coralloidoolithus Temporal range:
| |
|---|---|
Egg fossil classification
| |
| Basic shell type: | †Dinosauroid-spherulitic |
| Oofamily: | †Stalicoolithidae |
| Oogenus: | †Coralloidoolithus Wang, Wang, Zhao & Jiang, 2012 |
| Oospecies | |
| |
History
editXixia Countywas first excavated for fossils by a Geological Team of the Henan Geological Bureau in 1974. Fossils continued to be excavated there, but were not extensively studied until 1994 when Fanget al.received funding from theNational Natural Science Foundation of China.Under this sponsorship, with support of theGeological Profession Foundationand theGeological Science Item Foundation of MGMR,a multidisciplinary team of Chinese paleontologists took on the task of analyzing the geology and paleontology of these eggs. In 1998, Fanget al.described numerous new ootaxa, including the oospecies"Paraspheroolithus"shizuiwanensis.[2]
Further specimens were uncovered inTiantaiin 2000; these were referred to"P."cf.shizuiensis.[3]In 2012 multiple complete and near-complete eggs were discovered in Tiantai by the Chinese paleontologists Wang Qiang, Wang Xiaolin, Zhao Zikui, and Jiang Yan'gen. They named a new oogenus,Coralloidoolithus,forP. shizuiwanensis,and referred several of their newly discovered specimens toC. shizuiwanensis.[1]They also synonymized this oospecies with theMongolianDendroolithusmicroporosusandSpheroolithusoosp.fromSouth Koreabased on similarities in microstructure.[1]
Description
editThe first specimens discovered were only fragments, but based on impressions they were estimated to be 5–6 cm (2.0–2.4 in) in diameter.[2]The complete eggs discovered in Tiantai are larger, ranging from 8.72 to 10.38 cm (3.43 to 4.09 in) in length by 6.85 to 9.24 cm (2.70 to 3.64 in) wide.[1]They are roughly spherical. Wanget al.(2012) described them as having a rough surface,[1]but the original"P." shizuiwanensisspecimens were noted by Fanget al.to have a smooth surface.[2]Dendroolithus macroporosusand theSpheroolithusspecimens referred toC. shizuiwanensisare also smooth-shelled.[4][5]
Coralloidoolithus'sshell is typically about 2.6 mm thick. It has similar microstructures to the other stalicoolithids; it has a very thin cone layer (the inner layer of the eggshell), making up only about 1/10 of the eggshell's thickness, and its columnar layer is divided into three zones. Secondary shell units make up the outermost of these zones and also fill many of the pore canals. The middle zone is characterized by light and dark bands and the innermost zone of the columnar layer has horizontal growth lines.[1]Its pores are irregular and meandering.[1]Coralloidoolithuscan be distinguished fromStalicoolithusby having a thinner eggshell and by having fewer secondary shell units.Shixingoolithusis larger thanCoralloidoolithusand has a thicker cone layer.[1]
Distribution
editCoralloidoolithus shizuiwanensisis found at severalUpper Cretaceoussites, including at theSangping FormationinXixia County,Henan[2]and at theChichengshan FormationTiantai County,Zhejiang.[1]Also, specimens found in theGobi Desert[1]and inBosung County,Chullanam-do Province,South Korea[5]have been referred to this oospecies.[1]
Classification
editCoralloidoolithusis amonotypicoogenus containing onlyC. shizuiwanensis.It is classified alongsideStalicoolithusandShixingoolithusin the oofamily Stalicoolithidae.[1]
See also
edit
References
edit- ^abcdefghijklWang Q, Wang X L, Zhao Z K, and Jiang Y G. (2012). "A new oofamily of dinosaur egg from the Upper Cretaceous of Tiantai Basin, Zhejiang Province, and its mechanism of eggshell formation"Chinese Science Bulletin.57: 3740-3747. doi: 10.1007/s11434-012-5353-2
- ^abcdPhương hiểu tư; lư lập ngũ; trình chính võ; trâu dụ bình; vương nghị dân; trần khắc tiều; doãn; trăn; vương hiểu hồng; lưu kim như; tạ hoành lượng; lặc duyệt cao (1998).Hà nam tây hiệp bạch ác kỷ đản hóa thạch.Địa chất xuất bản xã.
- ^Fang, Xiaosi; Wang, Yaozhong; Jiang, Yangen (2000). "On the Late Cretaceous fossil eggs of Tiantai, Zhejiang".Geological Review.46(1): 105–112.
- ^Ribeiro, V.; Mateus, O.; Holwerda, F.; Araujo, R.; Castanhinha, R. (2014). "Two new theropod egg sites from the Late Jurassic Lourinhã Formation, Portugal".Historical Biology.26(2): 206–217.doi:10.1080/08912963.2013.807254.S2CID55315504.
- ^abHuh, Min; Zelenitsky, Darla K. (2002). "Rich Dinosaur Nesting Site from the Cretaceous of Bosung County, Chullanam-Do Province, South Korea".Journal of Vertebrate Paleontology.22(3): 716–718.doi:10.1671/0272-4634(2002)022[0716:rdnsft]2.0.co;2.