Arundel Formation
Arundel Formation Stratigraphic range: Lower Cretaceous |
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Type | sedimentary |
Unit of | Potomac Group |
Underlies | Patapsco Formation |
Overlies | Patuxent Formation |
Thickness | up to 125 feet[1] |
Lithology | |
Primary | clay |
Location | |
Region | ![]() |
Country | United States |
Type section | |
Named by | W. B. Clark, 1897[1] |
The Arundel Formation, also known as the Arundel Clay, is a clay-rich sedimentary rock formation, within the Potomac Group, found in Maryland[2] of the United States of America. It is of Aptian age (Lower Cretaceous). This rock unit had been economically important as a source of iron ore, but is now more notable for its dinosaur fossils. Although often considered a formation, it may be only oxbow swamp facies within the Potomac Group.[3]
Contents
Vertebrate paleofauna
Dinosaurs
Dinosaurs present include possibly the large theropod Acrocanthosaurus,[4][5] the poorly known theropods "Allosaurus (or "Dryptosaurus") medius", "Creosaurus (or "Dryptosaurus") potens" (also known as "Capitalsaurus"), and "Coelurus gracilis", the ornithomimosaurian "Coelosaurus affinis", the sauropods Astrodon and Pleurocoelus, the nodosaurid Priconodon,[6] a possible basal ceratopsian, and potentially the ornithopod Tenontosaurus.[3] Other vertebrates are not as well-known from the formation, but include a freshwater shark, a lungfish, at least three genera of turtles, and at least one crocodilian.[3]
Color key
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Notes Uncertain or tentative taxa are in small text; |
Dinosaurs reported from the Arundel Formation | ||||||
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Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
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"A." medius[7] |
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"Tooth."[8] |
An indeterminate theropod tooth. |
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A. johnstoni[9] |
"Tooth."[11] |
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"C." potens |
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"Vertebra."[8] |
A neotheropod. |
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C. affinis[7] |
Junior synonym of "Dryosaurus" grandis |
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"C." gracilis |
"Manual ungual and teeth."[8] |
Probably a dromaeosaurid. |
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"C." potens[7] |
Reclassified as "Capitalsaurus" potens |
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Indeterminate[7] |
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A dromaeosaurid |
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"D." grandis |
|
"Limb elements."[13] |
An indeterminate theropod sometimes considered a species of Ornithomimus and originally described as a species of the ornithischian Dryosaurus |
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"D." medius |
Synonym of "Allosaurus" medius |
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"D." potens[7] |
Synonym of "Capitalsaurus" potens |
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"O." affinis |
Junior synonym of "Druosaurus" grandis |
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P. altus[7] |
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"Tibia [and] fibula."[14] |
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P. nanus[7] |
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Indeterminate[10] |
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P. crassus[7] |
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"Teeth, tibia."[15] |
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Indeterminate[16] |
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Pterosaurs
Unassigned pteradactyloid tracks.[17]
Color key
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Notes Uncertain or tentative taxa are in small text; |
Pterosaurs of the Arundel Formation | ||||||
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Genus | Species | Location | Stratigraphic position | Abundance | Notes | Images |
Other fossils
W. B. Clark (1897) described lignitized trunks of trees often found in upright positions with their roots still intact.[1]
G. J. Brenner (1963) described spores and pollen within the formation.[18]
See also
Footnotes
- ↑ 1.0 1.1 1.2 Clark, W.B., 1897, Outline of present knowledge of the physical features of Maryland: Maryland Geological Survey Volume Series, v. 1, pt. 3, p. 172-188. [1]
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- ↑ 3.0 3.1 3.2 Lua error in package.lua at line 80: module 'strict' not found.
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- ↑ 7.00 7.01 7.02 7.03 7.04 7.05 7.06 7.07 7.08 7.09 7.10 7.11 7.12 7.13 7.14 7.15 7.16 7.17 7.18 7.19 7.20 7.21 7.22 7.23 "3.25 Maryland, United States; 1. Arundel Clay," in Weishampel, et al. (2004). Page 556.
- ↑ 8.0 8.1 8.2 "Table 4.1," in Weishampel, et al. (2004). Page 78.
- ↑ 9.0 9.1 "3.25 Maryland, United States; 1. Arundel Clay" and "3.34 Washington D. C., United States; 1. Arundel Clay," in Weishampel, et al. (2004). Page 556.
- ↑ 10.0 10.1 10.2 "3.34 Washington D. C., United States; 1. Arundel Clay," in Weishampel, et al. (2004). Page 556.
- ↑ "Table 13.1," in Weishampel, et al. (2004). Page 270.
- ↑ Kranz, D. 1998. Mostly Dinosaurs: A Review of the Vertebrates of the Potomac Group (Aptian Arundel Formation), USA, in Lucas, Kirkland and Estep, eds., 1998: 235-238.
- ↑ "Table 6.1," in Weishampel, et al. (2004). Page 139.
- ↑ "Table 13.1," in Weishampel, et al. (2004). Page 266.
- ↑ "Table 17.1," in Weishampel, et al. (2004). Page 368.
- ↑ 16.0 16.1 Listed as "?Tenontosaurus sp." in "3.25 Maryland, United States; 1. Arundel Clay," in Weishampel, et al. (2004). Page 556.
- ↑ 17.0 17.1 17.2 Lockley, M.; Harris, J.D.; and Mitchell, L. 2008. "A global overview of pterosaur ichnology: tracksite distribution in space and time." Zitteliana. B28. p. 187-198. ISSN 1612 - 4138. Cite error: Invalid
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tag; name "Lockleyetal2008" defined multiple times with different content - ↑ Brenner, Gilbert J., 1963, The spores and pollen of the Potomac Group of Maryland: Maryland Geological Survey Bulletin, no. 27, 215 p. [2]
References
- Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.
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