Cherokee-Sanford Brick Clay Pit (USNM Loc. 41614, 41615): Late/Upper Aptian, Maryland
collected by Kranz, Lipka, Cifelli 1980–

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
unclassified
Exesipollenites tumulus Balme 1957
Equisetopsida - Cheirolepidiaceae
Classopollis torosus Burger 1965
Equisetopsida - Cupressales
Inaperturopollenites dubius Thomson and Pflug 1953
Equisetopsida - Araucariaceae
Araucariacites australis Cookson 1947
Cycadopsida - Cycadales
Eucommiidites troedssonii Potonié 1958
Angiospermae - Chloranthales - Chloranthaceae
Clavatipollenites hughesii Kemp 1968
Pteridopsida
Cyathidites minor Couper 1953
Polypodiopsida - Schizaeales - Schizaeaceae
Schizaeaceae indet. Kaulfuss
Bivalvia
Bivalvia indet. Linnaeus 1758
Lipka et al. 2006
unclassified
Actinopterygii indet. (Cope 1887)
Frederickson et al. 2018 3 specimens
USNM 521171–73
Reptilia
Astrodon johnstoni Leidy 1865
Lipka et al. 2006 15 specimens
nomen dubium belonging to Sauropoda
USNM 497760-497774
Ankylosauria indet. (Osborn 1923)
Frederickson et al. 2018 5 specimens
USNM 497778–82
Priconodon crassus Marsh 1888
Lipka et al. 2006 3 specimens
nomen dubium belonging to Ankylosauria
USNM 497775-49777
Neoceratopsia indet. Sereno 1986
Chinnery et al. 1998 3 specimens
USNM 337977, 497708, 497783
? Tenontosaurus sp. Ostrom 1970
Lipka et al. 2006 1 specimen
USNM 244564 ("Magulodon muirkirkensis")
Theropoda indet. (Marsh 1881)
Frederickson et al. 2018 10 specimens
USNM 497750–59
Reptilia - Dromaeosauridae
aff. Richardoestesia sp. Currie et al. 1990
Frederickson et al. 2018 2 specimens
UNSM 497748-49
Deinonychus antirrhopus Ostrom 1969
Lipka et al. 2006 9 specimens
USNM 497715, 497719-20, 497727, 497732, 497734–36, 497741
    = Deinonychus sp. Ostrom 1969
Frederickson et al. 2018
Reptilia
"Coelurus" gracilis Marsh 1888
Lipka 1998
nomen dubium belonging to Coelurus
teeth
Ornithomimosauria indet. (Barsbold 1976)
Frederickson et al. 2018 8 specimens
NHRD-AP 2015.v.103.9, proximal and distal ends of a humerus; NHRD-AP 2014.s.196, manual ungual; NHRD-AP 2016.5.503, caudal vertebra; NHRD-AP 2014.s.195, NHRD-AP 2014.s.197, NHRD-AP 2014.s.198, USNM PAL 529423, NHRD-AP 2016.v.1104, pedal unguals
Reptilia - Carcharodontosauridae
cf. Acrocanthosaurus sp. Stovall and Langston 1950
Lipka 1998 12 specimens
USNM 497718, 497722–26, 497742–47
    = Acrocanthosaurus sp. Stovall and Langston 1950
Frederickson et al. 2018
cf. Acrocanthosaurus atokensis Stovall and Langston 1950
Carrano 2023 1 individual
USNM 466054, a partial postcranial skeleton
Reptilia - Goniopholididae
cf. Goniopholidae indet. (Cope 1875)
Frederickson et al. 2018 79 specimens
original and current combination Goniopholididae
USNM 609352–62, 609387–455
Reptilia - Pholidosauridae
cf. Pholidosauridae indet. von Zittel and Eastman 1902
Frederickson et al. 2018 13 specimens
USNM 609363–75
Reptilia - Bernissartiidae
cf. Bernissartiidae indet. (Dollo 1883)
Frederickson et al. 2018 2 specimens
USNM 609376-77
Reptilia
Arundelemys dardeni n. gen., n. sp. Lipka et al. 2006
Lipka et al. 2006 1 specimen
USNM 497740
Glyptops caelatus Hay 1908
Kranz 1998 1 specimen
nomen dubium belonging to Paracryptodira
USNM 497784
Naomichelys sp. Hay 1908
Frederickson et al. 2018
Mammalia - Multituberculata
Argillomys marylandensis n. gen., n. sp. Cifelli et al. 2013
Cifelli et al. 2013 1 specimen
USNM 497739, left M2
Mammalia - Eutriconodonta - Triconodontidae
Arundelconodon hottoni n. gen., n. sp. Cifelli et al. 1999
Cifelli et al. 1999 2 specimens
Additional specimen described by Rose et al. 2001 DUPLICATE REF 1222 or 1226 or 1227 (1 measurement)
Dipnoi - Ceratodontidae
Ceratodus sp. Agassiz 1838
Frederickson et al. 2018 2 specimens
USNM 521174, 521175
Dipnoi indet. (Müller 1884)
Lipka et al. 2006 1 specimen
USNM 508543
    = Ceratodus kranzi n. sp. Frederickson et al. 2016
Frederickson et al. 2016
Actinopteri
Holostei indet. (Müller 1846)
Frederickson et al. 2018 30 specimens
USNM 497788–807, 521140–54
Actinopteri - Lepisosteiformes
cf. Lepidotes sp. Agassiz 1832
Frederickson et al. 2018 13 specimens
USNM 521155–67
Actinopteri - Amiiformes
Amiidae indet. Huxley 1861
Lipka et al. 2006 2 specimens
USNM 497786-87
    = cf. Amiiformes indet. Hay 1929
Frederickson et al. 2018
Actinopteri - Amiiformes - Amiidae
cf. Vidalamiinae indet. Grande and Bemis 1998
Frederickson et al. 2018 3 specimens
USNM 521168–70
Actinopteri
Teleostei indet. (Müller 1846)
Frederickson et al. 2018 1 specimen
USNM 497785
Chondrichthyes - Hybodontiformes - Hybodontidae
Hybodontidae indet. (Agassiz 1834)
Lipka et al. 2006 54 specimens
USNM 521185-521189, 609277-609320, 521179-521181, 521183-521184
Egertonodus basanus (Egerton 1845)
Frederickson et al. 2018 16 specimens
USNM 609321-–36, 521182
Hybodus ensis Woodward 1916
Frederickson et al. 2018 15 specimens
recombined as Planohybodus ensis
USNM 609337–51
see common names

Geography
Country:United States State/province:Maryland County:Prince George's
Coordinates: 39.1° North, 76.9° West (view map)
Paleocoordinates:32.9° North, 31.3° West
Basis of coordinate:stated in text
Geographic resolution:outcrop
Time
Period:Cretaceous Epoch:Early/Lower Cretaceous
Stage:Aptian 10 m.y. bin:Cretaceous 3
*Period:Early/Lower Cretaceous
Key time interval:Late/Upper Aptian
Age range of interval:122.46000 - 112.03000 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Geological group:Potomac Formation:Arundel Clay
Stratigraphic resolution:group of beds
Stratigraphy comments: Palynology of the Potomac Group suggests a late Aptian age for the Arundel facies (Brenner, 1963; Doyle and Robbins, 1977; Hochuli et al., 2006; Doyle, 2012)
Arundel Clay facies of the Patuxent Formation (Aptian, Lower Cretaceous).
Lithology and environment
Primary lithology:concretionary,gray carbonaceous claystone
Secondary lithology:brown,red claystone
Includes fossils?Y
Lithology description: ...rock also happens to be a prolific source of concretions, carbonized wood, and other unwanted residues.
Environment:wet floodplain
Geology comments: "oxbow swamp deposits"
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils,mesofossils,microfossils
Preservation of anatomical detail:medium
Associated major elements:some
Disassociated major elements:many
Disassociated minor elements:many
Fragmentation:frequent
Spatial resolution:parautochthonous
Collection methods and comments
Collection methods:bulk,selective quarrying,surface (float),surface (in situ),sieve,field collection
Reason for describing collection:taxonomic analysis
Museum repositories:UNSM
Collectors:Kranz, Lipka, Cifelli Collection dates:1980s–present
Collection method comments: A sustained field program by one of us (T.R.L.) resulted in the recovery of many new fossils from a single site in the Arundel Clay. The site, formerly mined commercially for clay, is now known as Dinosaur Park, managed by the Prince George’s County Department of Parks and Recreation. Previously described fossils from the site, USNM locality 41614, were obtained by surface prospecting (Lipka 1998; Cifelli et al. 1999; Rose et al. 2001; Lipka et al. 2006) and include those of the triconodontid mammal Arundelconodon hottoni Cifelli et al., 1999. The specimen described herein is the single mammalian fossil obtained through screenwashing and associated concentration techniques, aimed at recovery of vertebrate microfossils. The fossil-yielding zone at the site is reasonably productive insofar as fragmentary bones and teeth of large vertebrates are concerned. Informative microfossils are abundant at USNM locality 41614 (T.R.L. and R.L.C., work in progress). However, processing of washed concentrate is impeded considerably by the fact that the rock also happens to be a prolific source of concretions, carbonized wood, and other unwanted residues. Rock matrix was reduced through a two-phase screenwashing process (standard water wash followed by kerosene displacement method); further concentrated using the heavy liquid ZnBr2; and picked under a binocular dissecting microscope, using established procedures (see Cifelli et al. 1996 and references therein).
Metadata
Also known as:Hotton locality; Dinosaur Park, M-NCPPC, Washington Brick Company; Muirkirk
Database number:14376
Authorizer:J. Alroy, M. Carrano, R. Benson, E. Vlachos Enterer:J. Alroy, F. Aspromonte, R. Benson, M. Carrano
Modifier:M. Uhen Research group:vertebrate
Created:2002-05-15 00:00:00 Last modified:2023-09-29 12:59:47
Access level:the public Released:2002-05-15 00:00:00
Creative Commons license:CC BY
Reference information

Primary reference:

83879. G. J. Brenner. 1963. The spores and pollen of the Potomac Group of Maryland. State of Maryland Board of Natural Resources, Department of Geology, Mines and Water Resources Bulletin 27:1-215 [M. Carrano/M. Carrano]

Secondary references:

84746 C. D. Brownstein. 2017. Description of Arundel Clay ornithomimosaur material and a reinterpretation of Nedcolbertia justinhofmanni as an "Ostrich Dinosaur": biogeographic implications. PeerJ 5:e3110:1-20 [M. Carrano/M. Carrano]
87438 M. T. Carrano. 2023. First definitive record of Acrocanthosaurus (Theropoda: Carcharodontosauridae) in the Lower Cretaceous of eastern North America. Cretaceous Research 157(105814):1-18 [E. Vlachos/F. Aspromonte]
14087ETE B. J. Chinnery, T. R. Lipka, J. I. Kirkland, J. M. Parrish, and M. K. Brett-Surman. 1998. Neoceratopsian teeth from the Lower to Middle Cretaceous of North America. In S. G. Lucas, J. I. Kirkland, J. W. Estep (eds.), Lower and Middle Cretaceous Terrestrial Ecosystems, New Mexico Museum of Natural History and Science Bulletin 14:297-302 [M. Carrano/M. Carrano/M. Carrano]
46392 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 [R. Benson/R. Benson/M. Carrano]
1222 R. L. Cifelli, T. R. Lipka, C. R. Schaff and T. B. Rowe. 1999. First Early Cretaceous mammal from the eastern seaboard of the United States. Journal of Vertebrate Paleontology 19(2):199-203 [J. Alroy/J. Alroy/J. Alroy]
77019 S. W. Evers, Y. Rollot, and W. G. Joyce. 2021. New interpretation of the cranial osteology of the Early Cretaceous turtle Arundelemys dardeni (Paracryptodira) based on a CT-based re-evaluation of the holotype. PeerJ 9:311495:1-29 [E. Vlachos/E. Vlachos/P. Mannion]
60062 J. A. Frederickson, T. R. Lipka, and R. L. Cifelli. 2016. A new species of the lungfish Ceratodus (Dipnoi) from the Early Cretaceous of the eastern U.S.A. Journal of Vertebrate Paleontology 36(4):e1136316:1-5 [M. Carrano/M. Carrano]
66681 J. A. Frederickson, T. R. Lipka, and R. L. Cifelli. 2018. Faunal composition and paleoenvironment of the Arundel Clay (Potomac Formation; Early Cretaceous), Maryland, USA. Palaeontologia Electronica 21(2):31A:1-24 [P. Mannion/P. Mannion/M. Carrano]
78397 P. Kranz. 1996. Notes on the sedimentary iron ores of Maryland and their dinosaurian fauna. In D. K. Brezinski & J. P. Reger (ed.), Studies in Maryland Geology in Commemoration of the Centennial of the Maryland Geological Survey. Maryland Geological Survey Special Publication 3:87-111 [M. Carrano/M. Carrano/M. Carrano]
40879 P. M. Kranz. 1998. New fossil turtles from the Potomac Group (Arundel Formation) (Aptian age), Maryland, USA. Bulletin - New Mexico Museum of Natural History and Science 14:193-194 [M. Uhen/M. Shalap]
30610ETE T. R. Lipka. 1998. The affinities of the enigmatic theropods of the Arundel Clay facies (Aptian), Potomac Formation, Atlantic Coastal Plain of Maryland. In S. G. Lucas, J. I. Kirkland, J. W. Estep (eds.), Lower and Middle Cretaceous Terrestrial Ecosystems; New Mexico Museum of Natural History and Science Bulletin 14:229-234 [M. Carrano/M. Carrano]
30601ETE T. R. Lipka, F. Therrien, D. B. Weishampel, H. A. Jamniczky, W. G. Joyce, M. W. Colbert, and D. B. Brinkman. 2006. A new turtle from the Arundel Clay facies (Potomac Formation, Early Cretaceous) of Maryland, USA. Journal of Vertebrate Paleontology 26(2):300-307 [M. Carrano/M. Carrano/M. Carrano]
83880 E. I. Robbins. 1991. Age of Early Cretaceous palynomorphs in the Muirkirk clay pit fossil locality. United States Geological Survey Open-File Report 91-613:1-7 [M. Carrano/M. Carrano]
4182 K. D. Rose, R. L. Cifelli, and T. R. Lipka. 2001. Second triconodont dentary from the Early Cretaceous of Maryland. Journal of Vertebrate Paleontology 21(3):628-632 [J. Alroy/J. Alroy/J. Alroy]
85047 D. B. Weishampel and L. Young. 1996. Dinosaurs of the East Coast xiii-275 [M. Carrano/M. Carrano]