Protoceratopsidovumis anoogenusofdinosaur eggfromMongolia.Despite its name (which means "eggs ofProtoceratops"[1]), it does not represent the eggs of aprotoceratopsid,but rather the eggs ofmaniraptorantheropods.[2][3]
| Protoceratopsidovum Temporal range:Campanian
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|---|---|
Egg fossil classification
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| Basic shell type: | †Dinosauroid-prismatic |
| Oofamily: | †Prismatoolithidae |
| Oogenus: | †Protoceratopsidovum Mikhailov,1994 |
| Oospecies | |
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Description
editProtoceratopsidovumeggs are extremely abundant in theDjadokhtaandBarun Goyot Formations.[4]P. sincerumandP. minimumeggs both have a smooth surface, whereas those ofP. fluxuosumhave fine ornamentation around the equatorial part.[4]The eggs are elongated and asymmetrical, with a two-layered prismatic shell generally resembling the eggs ofTroodon.[5]They were laid in pairs.[3]
Parataxonomy
editThe eggs ofProtoceratopsidovumare classified in theoofamilyPrismatoolithidae.[4]They were originally thought to be eggs ofProtoceratops(hence the name) because they are extremely common at the same sites asProtoceratops.[4]However, more recent research has cast doubt on this: acladistic analysisin2008,by Zelenitsky and Therrien, found them to be the eggs ofmaniraptorans.[3]
Palaeobiology
editThe shape, structure, and arrangement of eggs ofProtoceratopsidovumand its relatives provide some insight into the palaeobiology of fossil eggs. Their asymmetrical shape (resemblingbirdeggs) suggests that the process of egg formation was similar to that of birds. Unlike bird eggs (which are laid one at a time),Protoceratopsidovumeggs were laid in pairs because the mother would have two functioningoviductswhich would both lay a single egg simultaneously, contrasting with modern birds, which have only one functional oviduct. Though no fossils of parentsincubatingProtoceratopsidovumeggs have been found, their identification as maniraptoran eggs would imply that they were incubated.[3]
See also
editReferences
edit- ^Zelenitsky, D., and Currie, P. (2004) "A Cladistic Analysis of Theropod Ootaxa."Journal of Vertebrate Paleontology.Vol. 24, Supplement 003: Abstracts of Papers Sixty-Fourth Annual Meeting Society of Vertebrate Paleontology Adams Mark Hotel Denver, Colorado November 3–6.
- ^Carpenter, K. 1999. Eggs, Nests, and Baby Dinosaurs: A Look at Dinosaur Reproduction (Life of the Past). Indiana University Press, Bloomington, Indiana.
- ^abcdZelenitsky, D. K. And Therrien, F. (2008), "Phylogenetic Analysis Of Reproductive Traits Of Maniraptoran Theropods And Its Implications For Egg Parataxonomy."Palaeontology,51: 807–816.doi:10.1111/J.1475-4983.2008.00770.X
- ^abcdMikhailov, K.E. (2000). "Eggs and eggshells of dinosaurs and birds from the Cretaceous of Mongolia."The age of dinosaurs in Russia and Mongolia.Cambridge University Press, Cambridge. pp. 560–572.
- ^Moreno-Azanza, M., Canudo, J. I., & Gasca, J. M. (2014). Spheroolithid eggshells in the Lower Cretaceous of Europe. Implications for eggshell evolution in ornithischian dinosaurs. Cretaceous Research,51, 75–87.