Astrodon
Astrodon | |
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Life restoration | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | †Sauropodomorpha |
Clade: | †Sauropoda |
Clade: | †Macronaria |
Clade: | † Titanosauriformes
|
Genus: | †Astrodon Leidy, 1865[1] |
Species: | †A. johnstoni
|
Binomial name | |
†Astrodon johnstoni Leidy, 1865
| |
Synonyms | |
|
Astrodon (aster: star, odon: tooth) is a
Discovery and species
Two dinosaur teeth were received in late November 1858 by chemist
In 1888,
However, other authors did not find the argument in favor of the synonymization of Astrodon and Pleurocoelus so convincing. According to Peter Rose (2007) it has not been demonstrated that either the teeth of Astrodon johnstoni or those attributed to Pleurocoelus are "morphologically diagnostic among titanosauriforms", which limits their utility when it comes to distinguishing them from the teeth of other taxa. The type series of Pleurocoelus nanus and P. altus (four vertebrae and two hindlimbs bones, respectively) cannot be directly compared to the teeth from the type series of Astrodon, so any comparison has to be conducted based on the referred specimens of Pleurocoelus. These, however, are all isolated bones from the Arundel Formation, which themselves were referred to Pleurocoelus only based "on proximity of the localities and the size of the bones". Rose concludes that, as Astrodon is not based on the diagnostic material, "new discoveries should not be aligned with that genus" and that "the argument to synonymize the two taxa, Astrodon and Pleurocoelus, seems unfounded". The type material of Pleurocoelus may not be diagnostic as well, according to the author.[10]
A similar argument was made by Michael D. d'Emic (2013). The author did not find any diagnostic features of the type material of Astrodon johnstoni, Pleurocoelus nanus and P. altus and considered the three taxa to be nomina dubia; according to the author there is no direct evidence that any sauropod bones from the Arundel Formation other than their type series can be referred to these taxa. D’Emic also stated that the exact provenance of the bones from the type series of Pleurocoelus nanus is uncertain and thus "these bones could represent a chimera of individuals or taxa". The author also commented on the diagnosis of Astrodon johnstoni proposed by Carpenter and Tidwell (which was based on all of the sauropod material from the Arundel Formation, not only on the teeth from the type series); he claimed that most of the supposed autapomorphies of this taxon "are indistinguishable compared to other sauropods such as Camarasaurus (...) and/or are related to the juvenile nature of the material".[11]
Paleoecology
Habitat
The
This formation is part of the Potomac Group that includes formations not only in Maryland but also in parts of Washington D. C., Delaware and Virginia. The Arundel Formation was deposited on the edge of the expanding Atlantic Ocean basin. The region preserved in this formation was a broad, and generally flat plain with several streams running across it, probably similar to the modern day coastal regions of Alabama, Georgia, Louisiana and Mississippi.Fossil material assigned to Astrodon has also been found in two Oklahoma localities of the Antlers Formation, which stretches from southwest Arkansas through southeastern Oklahoma and into northeastern Texas.[12][13] This geological formation has not been dated radiometrically. Scientists have used biostratigraphic data and the fact that it shares several of the same genera as the Trinity Group of Texas, to surmise that this formation was laid down during the Albian stage of the Early Cretaceous Period, approximately 110 mya.[14] The Papo Seco Formation of the Lusitanian Basin in Portugal also provided fossils referred to Astrodon.
Paleofauna
In what is now Maryland, Astrodon shared its
In prehistoric Oklahoma, Astrodon lived alongside other dinosaurs, such as the
Cultural references
In 1998, Astrodon johnstoni was named the state dinosaur of Maryland. Astrodon also appears in the novel Raptor Red by Robert T. Bakker, as prey of Utahraptor.
A life-sized Astrodon model (featuring a wound on its left rear leg) is displayed in the Terror of the South exhibit on the third floor of the North Carolina Museum of Natural Sciences.[25][26]
Another Astrodon model is also on display at the Maryland Science Center in Baltimore, MD.[27]
Astrodon was the state dinosaur of Texas, but has since been replaced with Sauroposeidon. [28]
References
- ^ McDavid SN & Perkins J (2023) The authorship of Astrodon (Dinosauria, Sauropoda): Leidy, 1865, not Johnston, 1859. The Bulletin of Zoological Nomenclature 80(1):109-111 doi: 10.21805/bzn.v80.a031
- ^ Weems, R. E., & Bachman, J. M. (2015). The Lower Cretaceous Patuxent Formation Ichnofauna of Virginia. Ichnos, 22(3-4), 208–219. https://doi.org/10.1080/10420940.2015.1063493
- ISBN 9781421414829.
- ISBN 9788575961773.
- ^ ISBN 978-0-253-34542-4.
- ^ Hatcher, John Bell (1903). "Discovery of remains of Astrodon (Pleurocoelus) in the Atlantosaurus beds of Wyoming". Annals of the Carnegie Museum of Natural History. 2: 9–14.
- ^ W.E. Swinton, 1936, "The dinosaurs of the Isle of Wight", Proceedings of the Geologists' Association 47(3): 204–220
- ^ Lapparent, A. F. de, & Zbyszewski, G., 1957, Les Dinosauriens du Portugal, Mémoires des Services Geologiques du Portugal. Nouvelle série, numéro 2, 63 pp
- ^ Kingham, R. F., 1962, "Studies of the sauropod dinosaur Astrodon Leidy", Proceedings of the Washington Junior Academy of Sciences, 1: 38–44
- ^ Rose, Peter J. (2007). "A new titanosauriform sauropod (Dinosauria: Saurischia) from the Early Cretaceous of central Texas and its phylogenetic relationships". Palaeontologia Electronica. 10 (2): 8A.
- S2CID 84742205.
- ^ P. Larkin. 1910. The occurrence of a sauropod dinosaur in the Trinity Cretaceous of Oklahoma. Journal of Geology 17:93–98
- ^ R. L. Cifelli. 1997. Oklahoma Geology Notes 57(1):4–17
- ^ Wedel, M. J., and Cifelli, R. L. 2005. Sauroposeidon: Oklahoma’s native giant. Oklahoma Geology Notes 65 (2):40–57.
- ISBN 978-0-520-24209-8.
- James I. Kirkland; J. W. Estep (eds.). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin. Vol. 14. pp. 225–228.
- James I. Kirkland; J. W. Estep (eds.). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin. Vol. 14. pp. 229–234.
- ^ R. L. Cifelli, C. L. Gordon, and T. R. Lipka. 2013. New multituberculate mammal from the Early Cretaceous of eastern North America. Canadian Journal of Earth Sciences 50(3):315–323
- ^ A. Bibbins. 1895. Notes on the paleontology of the Potomac Formation. The Johns Hopkins University Circulars 15(121):17–20
- ^ Weishampel, David B.; Barrett, Paul M.; Coria, Rodolfo A.; Le Loeuff, Jean; Xu Xing; Zhao Xijin; Sahni, Ashok; Gomani, Elizabeth, M.P.; and Noto, Christopher R. (2004). "Dinosaur Distribution", in The Dinosauria (2nd), p. 264.
- ^ Brinkman, Daniel L.; Cifelli, Richard L.; & Czaplewski, Nicholas J. (1998). "First occurrence of Deinonychus antirrhopus (Dinosauria: Theropoda) from the Antlers Formation (Lower Cretaceous: Aptian – Albian) of Oklahoma". Oklahoma Geological Survey Bulletin 146: 1–27.
- ^ Nydam, R. L. and R. L. Cifelli. 2002a. Lizards from the Lower Cretaceous (Aptian–Albian) Antlers and Cloverly formations. Journal of Vertebrate Paleontology. 22:286–298.
- ^ Cifelli, R. Gardner, J. D., Nydam, R. L., and Brinkman, D. L. 1999. Additions to the vertebrate fauna of the Antlers Formation (Lower Cretaceous), southeastern Oklahoma. Oklahoma Geology Notes 57:124–131.
- ^ Kielan-Jarorowska, Z., and Cifelli, R. L. 2001. Primitive boreosphenidan mammal (?Deltatheroida) from the Early Cretaceous of Oklahoma. Acta Palaeontologica Polonica 46: 377–391.
- ^ "Noah's Ravens: A Visit To the North Carolina Museum of Natural Sciences, Part II: Terror of the South & the Nature Research Center". Noah's Ravens. 2016-10-29. Archived from the original on 2021-09-15. Retrieved 2021-09-15.
- ^ "GDP: A couple of Carolina dinosaurs". Past in the Present. 2018-04-12. Archived from the original on 2021-09-15. Retrieved 2021-09-15.
- ^ "Dinosaur Mysteries". Maryland Science Center. Archived from the original on 2021-09-15. Retrieved 2021-09-15.
- ^ "TPWD Kids: Texas Symbols: Dinosaur". tpwd.texas.gov. Archived from the original on 2022-04-11. Retrieved 2022-04-11.
Further reading
- Johnston, C., 1859, "Note on odontography," Amer. Journal Dental Sci. 9:337–343.
- Kranz, P. M. 1996, "Notes on the Sedimentary Iron Ores of Maryland and their Dinosaurian Fauna", in Maryland Geological Survey Special Publication No. 3, pp. 87–115.
- Leidy, J 1865, Memoir on the extinct reptiles of the Cretaceous formations of the United States. Smithson. Contrib. Knowl. XIV: atr. VI: 1–135.
- Lucas, F. A. 1904, "Paleontological notes," Science (n.s.) XIX (480): 436–437.
- Lull, R. S. 1911, "The Reptillian Fauna of the Arundel Formation" and "Systematic Paleontology of the Lower Cretaceous Deposits of Maryland – Dinosauria", Lower Cretaceous: Maryland Geological Survey Systematic Reports, pp. 173–178, 183–211.
- Marsh, O. C. 1888, "Notice of a New Genus of Sauropoda and Other New Dinosaurs from the Potomac Group," American Journal of Science, 3rd Series, Vol. XXXV, pp. 89–94.