Digimorph, An NSF Digital Library at UT Austin, Texas
Browse the Library by:
 Scientific Names
 Common Names
 What's New ?
 What's Popular?
Learn More
Overview Pages
A Production of

Arundelemys dardeniFossil, Fossil Paracryptodire
Mr. Thomas Lipka - Arundel Project & Geobiological Research
Dr. Francois Therrien, Dr. David Weishampel, Dr. Heather Jamniczky, Dr. Walter Joyce, Dr. Matthew Colbert, and Dr. Donald Brinkman
Arundelemys dardeni
Click for help
Click for more information

National Museum of Natural History (USNM 497740) - holotype

Image processing: Dr. Jessie Maisano
Publication Date: 24 Jan 2007


Abstract from A New Turtle from the Arundel Clay Facies (Potomac Formation, Early Cretaceous) of Maryland, U.S.A., by T. R. Lipka, F. Therrien, D. B. Weishampel, H. A. Jamniczky, W. G. Joyce, M. W. Colbert and D. B. Brinkman, 2006 (Journal of Vertebrate Paleontology 26:300-307):

       A new paracryptodiran turtle, Arundelemys dardeni, gen. et sp. nov., is described on the basis of an        isolated, nearly complete skull from the Early Cretaceous Arundel Clay facies of Maryland, USA. The        basicranial region exhibits the paracryptodiran condition of a single foramen for the canalis caroticus        internus located midway along the basisphenoid. As revealed by CT scans, the basicranial region of        Arundelemys is unusual in that the right and left canales carotici interni merge just before reaching        the sella turcica and the canalis caroticus lateralis is very small or absent. A phylogenetic analysis        places Arundelemys dardeni as the basal-most member of the Paracryptodira. Within the        Paracryptodira, Arundelemys dardeni is most similar to Compsemys victa in general proportions.

About the Species

This specimen was collected from the Muirkirk locality of the Early Cretaceous Arundel Clay facies, Potomac Formation. It was made available to the University of Texas High-Resolution X-ray CT Facility for scanning by Dr. Donald Brinkman of the Royal Tyrrell Museum of Palaeontology. Funding for scanning was provided by Dr. Brinkman. Funding for image processing was provided by a National Science Foundation Digital Libraries Initiative grant to Dr. Timothy Rowe of The University of Texas at Austin.

Lateral view of skull

Dorsal view of skull

Ventral view of skull

About this Specimen

The specimen was scanned by Matthew Colbert on 16 November 2004 along the coronal axis for a total of 630 slices. Each 1024x1024 pixel slice is 0.095 mm thick, with an interslice spacing of 0.095 mm and a field of reconstruction of 44.5 mm.

About the


Bakker, R. T. 1988. A new latest Jurassic vertebrate fauna, from the highest levels of the Morrison Formation at Como Bluff, Wyoming, with comments on Morrison biochronology. Hunteria 2:1–19.

Bakker, R. T. 1998. Dinosaur mid-life crisis: the Jurassic–Cretaceous transition in Wyoming and Colorado; pp. 67–77 in S. G. Lucas, J. I. Kirkland, and J. W. Estep (eds.), Lower to Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Sciences Bulletin 14, Albuquerque.

Batsch, A. J. G. C. 1788. Versuch einer Anleitung, zur Kennnish und Geschichte der Thiere und Mineralien. Akademische Buchhandlung, Jena, 528 pp.

Baur, G. 1887. Ueber den Ursprung der Extremitäten der Ichthyopterygia. Jahresberichte und Mitteilungen des Oberrheinischen geologischen Vereines, Stuttgart 20:17–20.

Berry, E. W., 1911, Correlation of the Potomac Formation. Maryland Geologic Survey, Lower Cretaceous Volume:153–172.

Brinkman, D. B. 2003. Anatomy and systematics of Plesiobaena antiqua (Testudines: Baenidae) from the mid-Campanian Judith River Group of Alberta, Canada. Journal of Vertebrate Paleontology 23:146–155.

Brinkman, D. B., and E. L. Nicholls. 1991. Anatomy and relationships of the turtle Boremys pulchra (Testudines: Baenidae). Journal of Vertebrate Paleontology 11:302–315.

Brinkman, D. B., and E. L. Nicholls. 1993. The skull of Neurankylus eximius (Testudines: Baenidae) and a reinterpretation of the relationships of this taxon. Journal of Vertebrate Paleontology 13:273–281.

Brinkman, D. B., and J. H. Peng. 1993. Ordosemys leios, n.gen., n.sp., a new turtle from the Early Cretaceous of the Ordos Basin, Inner Mongolia. Canadian Journal of Earth Sciences 30:2128–2138.

Brinkman, D. B., and X. C. Wu. 1999. The skull of Ordosemys, an Early Cretaceous turtle from Inner Mongolia, People’s Republic of China, and the interrelationships of Eucryptodira (Chelonia, Cryptodira). Paludicola 2:134–147.

Brinkman, D. B., K. Stadtman, and D. Smith. 2000. New material of Dinochelys whitei Gaffney, 1979, from the Dry Mesa Quarry (Morrison Formation, Jurassic) of Colorado. Journal of Vertebrate Paleontology 20:269–274.

Chinnery, B. J., T. R. Lipka, J. I. Kirkland, M. J. Parrish, and M. K. Brett-Surman. 1998. Neoceratopsian teeth from the Lower to Middle Cretaceous of North America; pp. 297–302 in S. G. Lucas, J. I. Kirkland, and J. W. Estep (eds.), Lower to Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Sciences Bulletin 14.

Cifelli, R. L., T. R. Lipka, C. R. Schaff, and T. Rowe. 1999. First Early Cretaceous mammal from the eastern seaboard of the United States. Journal of Vertebrate Paleontology 19:199–203.

Cope, E. D. 1877. On reptilian remains from the Dakota beds of Colorado. Proceedings of the American Philosophical Society 24:193–196.

Doyle, J. A. 1992. Revised palynological correlations of the lower Potomac Group (USA) and the Cocobeach sequence of Gabon (Barremian–Aptian). Cretaceous Research 13:337–349.

Evans, J., and T. S. Kemp. 1976. A new turtle skull from the Purbeckian of England and a note on the early dichotomies of cryptodire turtles. Palaeontology 19:317–324.

Fontaine, W. M. 1879. Notes on the Mesozoic Strata of Virginia. American Journal of Science, 3rd Ser. 17:25–39, 151–157, 229–239.

Fontaine, W. M. 1889. The Potomac or younger Mesozoic flora. USGS Monograph 15:1–337.

Fraas, E. 1913. Proterochersis, eine pleurodire Schildkröte aus dem Keuper. Jahreshefte des Vereins für vaterländische Naturkunde in Württemberg 60:401–424.

Gaffney, E. S. 1972. The systematics of the North American family Baenidae (Reptilia, Cryptodira). Bulletin of the American Museum of Natural History 147:241–320.

Gaffney, E. S. 1975a. A taxonomic revision of the Jurassic turtles Portlandemys and Plesiochelys. American Museum of Natural History Novitates 2574:1–19.

Gaffney, E. S. 1975b. A phylogeny and classification of higher categories of turtles. Bulletin of the American Museum of Natural History 155:387–436.

Gaffney, E. S. 1976. Cranial morphology of the European Jurassic turtles Portlandemys and Plesiochelys. Bulletin of the American Museum of Natural History 157:487–544.

Gaffney, E. S. 1979. The Jurassic turtles of North America. Bulletin of the American Museum of Natural History 162:91–136.

Gaffney, E. S. 1983. The cranial morphology of the extinct horned turtle, Meiolania platyceps, from the Pleistocene of Lord Howe Island, Australia. Bulletin of the American Museum of Natural History 175:361–480.

Gaffney, E. S. 1996. The postcranial morphology of Meiolania platyceps and a review of the Meiolaniidae. Bulletin of the American Museum of Natural History 229:1–166.

Gaffney, E. S., and J. W. Kitching. 1994. The most ancient African turtle. Nature 369:55–58.

Gallup, M. R. 1988. A new look at the old dinosaurs of Maryland. The Maryland Naturalist 32:41–51.

Glaser, J. D. 1967. Nonmarine Cretaceous Sedimentation in the Middle Atlantic Coastal Plain. Ph.D. Dissertation, Johns Hopkins University, Baltimore, Maryland, 323 pp.

Glaser, J. D. 1968. Coastal Plain geology of southern Maryland. Maryland Geological Survey, Guidebook, 9th Annual Field Conference: 56.

Glaser, J. D. 1969. Petrology and origin of Potomac and Magothy (Cretaceous) sediments, middle Atlantic Coastal Plain. Maryland Geologic Survey, Report of Investigations no. 11, 101 pp.

Hack, J. T. 1977. Geologic map for land-use planning, Prince Georges County, Maryland. 1:62,500. U. S. Geological Survey Map I-1004.

Hansen, H. J. 1968. Geophysical Log Cross-Section Network of the Cretaceous Sediments of Southern Maryland. Maryland Geologic Survey RI No. 7, 46 pp.

Hansen, H. J. 1969. Depositional environments of subsurface Potomac Group in southern Maryland. AAPG Bulletin 53:1923–1937.

Hay, O. P. 1908. Fossil Turtles of North America. Carnegie Institution of Washington, Washington, D. C., 568 pp.

Hirayama, R., D. B. Brinkman, and I. G. Danilov. 2000. Distribution and biogeography of non-marine Cretaceous turtles. Russian Journal of Herpetology 7:181–198.

Hutchison, J. H. 2000. Diversity of Cretaceous turtle faunas of eastern Asia and their contribution to the turtle faunas of North America. Paleontological Society of Korea Special Publication No 4:27–38.

Hutchison, J. H., and P. A. Holroyd. 2003. Late Cretaceous and early Paleocene turtles of the Denver Basin, Colorado. Rocky Mountain Geology 38:121–142.

Joyce, W. J. 2004. Phylogeny, Nomenclature, and Ecology of Mesozoic Turtles. PhD Dissertation, Yale University, New Haven, Connecticut, 470 pp.

Joyce, W. G., J. F. Parham, and J. A. Gauthier. 2004. Developing a protocol for the conversion of rank-based taxon names to phylogenetically defined clade names, as exemplified by turtles. Journal of Paleontology 78:989–1013.

Khosatzky, L. I., and M. Mlynarski, 1971. The Chelonians from the Upper Cretaceous deposits of the Gobi Desert. Results of the Polish-Mongolian Palaeontological Expeditions—Part III. Palaeontologica Polonica 25:131–146.

Kranz, P. M. 1987. Dinosaurs in Maryland. Maryland Geological Survey, Educational Series No. 6, Baltimore, Maryland, 34 pp.

Kranz, P. M. 1996. Notes on the sedimentary iron ores of Maryland and their dinosaurian fauna; pp. 87–111 in D. K. Brezinski and J. P. Reager (eds.), Studies in Maryland Geology in Commemoration of the Centennial of the Maryland Geologic Survey, Maryland Geologic Survey, Special Publication 3.

Kranz, P. M. 1998. New fossil turtles from the Potomac Group (Arundel formation) (Aptian Age), Maryland, USA; pp. 193–194 in S. G. Lucas, J. I. Kirkland, and J. W. Estep (eds.), Lower to Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Sciences Bulletin 14.

Lambe, L. M. 1902. On the Vertebrata of the mid-Cretaceous of the Northwest Territory. Contribution to Canadian Paleontology 3:25–81.

Lambe, L. M. 1906. Boremys, a new chelonian genus from the Cretaceous of Alberta. Ottawa Naturalist 19:232–234.

Leidy, J. 1856. Notices of extinct Vertebrata discovered by Dr. F. V. Hayden, during the expedition to the Sioux country under the command of Lieut. G. K. Warren. Proceedings of the Academy of Natural Sciences 8:311–312.

Leidy, J., 1865. Memoir on the extinct reptiles of the Cretaceous formations of the United States. Smithsonian Contributions to Knowledge 14:1–135.

Leidy J. 1870. (Descriptions of Emys jeanesi, E. haydeni, Baena arenosa, and Saniwa ensidens.) Proceedings of the Academy of Natural Sciences Philadelphia, 1870:123–124.

Linnaeus, C. 1758. Systema Naturae, 10th ed. Salvii, Holmiae, vol. 1, 824 pp.

Lipka, T. R. 1998. The affinities of the enigmatic theropods of the Arundel Clay facies (Aptian), Potomac Formation, Atlantic Coastal Plain of Maryland; pp 229–234 in S. G. Lucas, J. I. Kirkland, and J. W. Estep (eds.), Lower to Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Sciences Bulletin 14.

Maddison, W. P., and D. R. Maddison. 1999. MacClade. Version 3.08. Sinauer Associates, Sunderland, Massachusettts.

Marsh, O. C. 1888. Notice of a new genus of Sauropoda and other dinosaurs from the Potomac Formation. American Journal of Science, 3rd Series 35:89–94.

Meylan, P. A., and E. S. Gaffney. 1989. The skeletal morphology of the Cretaceous cryptodiran turtle, Adocus, and the relationships of the Trionychoidea. American Museum Novitates 2941:1–60.

Meylan, P. A., R. T. J. Moody, C. A. Walker, and S. D. Chapman. 2000. Sandownia harrisi, a highly derived trionychoid turtle (Testudines: Cryptodira) from the Early Cretaceous of the Isle of Wight, England. Journal of Vertebrate Paleontology 20:522–532.

Milner, A. R. 2004. The turtles of the Purbeck Limestone Group of Dorset, Southern England. Palaeontology 47:1441–1467.

Moody, R. T. 1984. The relative importance of cranial/postcranial characters in the classification of sea turtles. Studia Geologica Salmanticensia Volumen Especial 1 (Studia Palaeocheloniologica I): 205–213.

Nopcsa, F. 1928. Palaeontological notes on reptiles. Geologica Hungarica, Palaeontology Series 1:1–84.

Owen, R. 1842. Report on British fossil reptiles, part II. Report for the British Association for the Advancement of Science, Plymouth 1841 11:60–204.

Rieppel, O. 1980. The skull of the Upper Jurassic cryptodire turtle Thalassemys, with a reconsideration of the chelonian braincase. Palaeontographica A 171:105–140.

Robbins, E. I. 1991. Age of the Early Cretaceous Palynomorphs in the Muirkirk Clay Pit Fossil Locality (Prince Georges County, Maryland). US Geological Survey Open File Report 91-613:1–7.

Russell, D. A. 1993. The role of Central Asia in dinosaurian biogeography. Canadian Journal of Earth Sciences 30:2002–2012.

Rütimeyer, L. 1873. Die fossilen Schildkröten von Solothurn und der übrigen Juraformation. Neue Denkschriften der Allgemeinen Schweizerischen Gesellschaft für die Gesammten Naturwissenschaften 25:1–185.

Swofford, D. L. 2002. PAUP*: Phylogenetic Analysis Using Parsimony (*and other methods). Version 4.0b10. Sinauer Associates, Sunderland, Massachusetts.

Wegner, T. 1911. Desmemys bertelsmeanni n.g. n.sp. Ein Beitrag sur Kenntnis der Thalassemydidae Rütimeyer. Palaeontographica 58:105–132.

Weishampel, D. B., and L. Young. 1996. Dinosaurs of the East Coast. Johns Hopkins University Press, Baltimore, Maryland, 275 pp.

Wiman, C. 1930. Fossile Schildkröten aus China. Palaeontologia Sinica, Series C 6:5–53.

& Links

Front page image.

Arundelemys dardeni

To cite this page: Mr. Thomas Lipka, Dr. Francois Therrien, Dr. David Weishampel, Dr. Heather Jamniczky, Dr. Walter Joyce, Dr. Matthew Colbert, and Dr. Donald Brinkman, 2007, "Arundelemys dardeni" (On-line), Digital Morphology. Accessed October 22, 2014 at http://digimorph.org/specimens/Arundelemys_dardeni/.

©2002 - UTCT/DigiMorph Funding by NSF
Hits=10876. Comments to info@digimorph.org