A single tooth recovered from the marine Mooreville Chalk Formation (Early Campanian) of western Alabama indicates the presence of dromaeosaurid theropods on the Appalachian subcontinent during the Late Cretaceous. The tooth compares closely with teeth referred to the small velociraptorine Saurornitholestes

Schwimmer, David R.

English

Columbus State University

THE JOURNAL OFTHE DELAWARE VALLEYPALEONTOLOGICAL SOCIETYVOLUME VII MAY 2004The Mosasaur, 7: 89-93First Record of a Velociraptorine Theropod (Tetanurae,Dromaeosauridae) from the Eastern Gulf Coastal United StatesCaitlin R. Kiernan1 and David R. Schwimmer2'#304 Liberty House, 2301 1st Avenue North, Birmingham, Alabama 35203-4320, and2 Department of Chemistry and Geology, Columbus State University,4225 University Avenue, Columbus, Georgia 31907-5465.ABSTRACT - A single tooth recovered from the marine Mooreville Chalk Formation (Early Campanian) of westernAlabama indicates the presence of dromaeosaurid theropods on the Appalachian subcontinent during the Late Cretaceous.The tooth compares closely with teeth referred to the small velociraptorine Saurornitholestes.IntroductionDromaeosaurid theropods were first described in the early1920's (Matthew and Brown, 1922; Osborn, 1924) from fossilremains recovered in Canada and Asia, and are now known tobe an important component of Late Cretaceous NorthAmerican dinosaur assemblages from the western side of theInterior Seaway. Dromaeosaurids have figured prominently inthe continuing and often-heated debate over the ancestry ofbirds, beginning with the works of J. H. Ostrom on the veloci-raptorine Deinonychus antirrhopus (Ostrom, 1969) and pro-ceeding to the spectacular recent discoveries of feathered dro-maeosaurids from a Lower Cretaceous (Early Barremian) kon-servat-Lagerstatte deposit in Liaoning, China (e.g. Xu et al.2001; Norell et al., 2002). Many workers currently view dro-maeosaurids as the closest sister-group to birds (see Padianand Chiappe, 1997). Indeed, so many synapomorphies(derived similarities) are shared by birds and dromaeosaurs, ithas even been speculated that the latter represent an early lin-eage of secondarily-flightless, predatory ground birds (Paul,1984, 2001), though this idea has not gained widespread sup-port. Two subtaxa of the Dromaeosauridae are presently rec-ognized: the Velociraptorinae (including Velociraptor), and theDromaeosauridae (represented by Dromaeosaurus, and per-haps others, including Utahraptor).The origins of the Dromaeosauridae probably extend backat least as far as the Late Jurassic (Currie, 1997), but the old-est fossils are in the Lower Cretaceous. Dromaeosaurids areknown from several Early Cretaceous (Neocomian) faunas ofwestern North America, including the giant Utahraptorostrommaysi (Kirkland et. al., 1993) from the Cedar MountainFormation (Barremian) of Utah, and Deinonychus antirrhopus(Ostrom, 1969) from the Cloverly Formation (Albian) ofMontana and Wyoming. Toward the close of the Cretaceous inNorth America, three dromaeosaurid species, Dromaeosaurusalbertensis (Matthew and Brown, 1922), Saurornitholesteslangstoni (Sues, 1978), and Bambiraptor feinbergi (Burnham,et al. 2000), were present in Cordilleran faunas from Judithianto Lancian times.However, until recently, there has been little evidence tosupport the presence of dromaeosaurids in the Late Cretaceousdinosaur faunas of eastern North America. Lipka (1998)reported a single tooth, possibly velociraptorine, from theArundel Clay facies of the Potomac Formation (EarlyCretaceous, Aptian) of Maryland. Subsequently, Lipka (per-sonal commun., 2000) has recovered a number of additionalteeth from the Arundel which may be referable to theVelociraptorinae. Teeth identified as dromaeosaurid have alsobeen recovered from the Marshalltown Formation (LateCampanian) near Ellisdale, New Jersey (B. Grandstaff, per-sonal commun., 2000). In this paper, we report the discoveryof a single dromaeosaurid tooth from the Mooreville ChalkFormation (Selma Group; latest Santonian—EarlyCampanian) of western Alabama, which provides the first evi-dence for the presence of dromaeosaurids in southeasternNorth America during the Late Cretaceous.Abbreviations and Institutions - - AGr, Alabama,Greene County; RMM, Red Mountain Museum, Birmingham,Alabama; RTMP, Royal Tyrrell Museum of Palaeontology,Drumheller, Alberta; ALMNH, Alabama Museum of NaturalHistory, Tuscaloosa.90 THE MOSASAUR — THE JOURNAL OF THE DVPS Vol.7Systematic Paleontology Description and DiscussionTHEROPODA Marsh 1881TETANURAE Gauthier, 1986COELUROSAURIA Huene, 1914MANIRAPTORIFORMES Holtz, 1996DROMAEOSAURIDAE Matthew and Brown, 1922VELOCIRAPTORINAE Barsbold, 1983cf. SAURORNITHOLESTES Sues, 1978Material examined — ALMNH 2001.1 (Fig. 1.1-1.3), asingle tooth. The specimen was collected by the senior authoras surface float during the excavation of a carapace and plas-tron of a toxochelyid turtle (Toxochelys moorevillensis).Locality and Horizon — ALMNH 2001.1 was collectedfrom a large series of erosional gullies in northwestern GreeneCounty, Alabama, near Old West Greene, Section 2, T. 22 N.,R. 1 W., Red Mountain Museum locality AGr-11 (exact local-ity data is on file at the Alabama Museum of Natural Historyand available to qualified researchers). Locality AGr-11 hasbeen collected by the senior author and others since at least1980 (extensive work was carried out there by RMM in 1981).The locality is especially rich in microvertebrates, includingsubadult mosasaurs, odontornithian birds (Ichthyornisl sp.),and a diverse assemblage of elasmobranchs and teleosts. Anumber of vertebrate species otherwise rare throughout theMooreville Chalk are fairly common here, including the scle-rorhychid sawfish Ischyrhiza mira and the small anacoracidshark Pseudocorax laevis. An exquisitely-preserved and near-ly-complete skeleton of the rare protostegid turtleCalcarichelys gemma (RMM 3164 and 3216) has also beenrecovered from the site (Hooks, 1998).AGr-11 exposes several meters of the lower unnamedmember of the Mooreville Chalk Formation, including (inascending order): 1) a lower layer of shelly, slightly sandy,whitish, marly chalk containing numerous burrows, ser-pulimorph worm tubes (Hamulus onyx, Hamulus squamosus,Serpulus sp.), disarticulated echinoid spines and plates, bry-ozoans, the balanomorph barnacle Acroscapellum sp., andlarge numbers of bivalves (Inoceramus sp., Agerostrea falcata,Ostrea sp., etc.) in reef-like concentrations; 2) a thinner bed ofdark gray marly chalk, largely devoid of bivalves (this bed mayhave originated under dysoxic conditions and contains manyof the site's microvertebrates); and 3) an upper layer of lightgray marly chalk, weathering to yellow.ALMNH 2001.1 was recovered from the uppermost beds,just beneath the soil zone. The portion of the Mooreville Chalkexposed at AGr-11 lies within the Exogyra ponderosa biozoneof Stephenson (1914) and was placed within the ClidastesAcme-zone by Kiernan (2002). A sediment sample from AGr-11 was analyzed at the Geological Survey of Alabama andrevealed a particularly high concentration of calcareous nanno-plankton (40-60 billion per cc). The sample is dominated byAspidolithus parcus parcus, and lacks Bukryaster hayi andQuadrum gartneri, indicating a mid-Early Campanian age forthe site (Nannofossil Zone 18a of Sissingh, 1977).ALMNH 2001.1 is well-preserved, though some minorcrushing is evident on the lingual surface. The tooth is strong-ly recurved distally and laterally compressed. Though the lin-gual surface is slightly flattened, the tooth is not D-shaped inbasal cross-section. Mesial denticles are present (Figs. 1.1,1.2) but minute, and the denticulate portion of the mesial cari-na extends less than halfway from the tip of the crown. In con-trast, the entire preserved length of the distal carina is denticu-late, and the denticles are large and elongate (Figs. 1.1, 1.3).Some of the denticles along the distal carina are hooked api-cally. Distally, there are 23 denticles (approximately 7 permm), and 19 to 22 denticles (approximately 9 per mm) are onthe mesial carina. The tip of ALMNH 2001.1 is missing, andthe root is not preserved. The preserved portion of the tooth hasa length of 3.6 mm mesio-distally, and a apical-basal height of4.9 mm. Currie et al. (1990) discussed the difficulties encoun-tered when measuring small theropod teeth and suggestedadoption of the fore-aft basal length (FABL) as a standard, asit exhibits a relatively constant relationship to the total toothlength. ALMNH 2001.1 has a FABL of 2.8 mm. All measure-ments were made with digital calipers.Ordinarily, isolated dinosaur teeth are of limited use inidentifying dinosaurian taxa to the genus or species level.However, previous authors (Currie et. al. 1990; Fiorillo andCurrie, 1994; Baszio, 1997) have established the enhanced tax-onomic utility of some isolated theropod teeth. Currie (et. al.,1990, 1995) considered the significant disparity in sizebetween mesial and distal denticles in the teeth of many dro-maeosaurids to be diagnostic for the Velociraptorinae. In thisrespect, and in general, ALMNH 2001.1 compares favorablywith RTMP 82.19.180, which has been referred toSauronitholestes langstoni (Currie et. al. 1990: fig. 8.2 S).Although this genus is a common component of dinosaurassemblages from the Late Campanian and Maastrichtian ofthe western U.S. and Canada, prior to this study the oldest andeasternmost report of possible Saurornitholestes remains wasfrom the Late Campanian Aguja Formation of BrewsterCounty, Texas (Rowe et. al., 1992). However, small theropodteeth from the Marshalltown Formation (Late Campanian) ofNew Jersey also compare favorably with Saurornitholestes (B.Grandstaff, personal commun., 2000).ALMNH 2001.1 indicates that a small velociraptorinedromaeosaurid, possibly congeneric with Saurornitholestes,inhabited the Appalachian subcontinent during the EarlyCampanian. The possible occurrence of this genus on bothsides of the Western Interior Seaway may provide evidencethat western and eastern dinosaur faunas were not completelyisolated during the Late Cretaceous. Alternatively, dro-maeosaurid populations may have descended in parallel oneither side of the Seaway from pre-Seaway (i.e. MiddleCretaceous) common ancestors. New studies and phylogeneticanalyses (Carr et al., in press; Schwimmer and Kiernan, 2001)indicate that tyrannosauroid theropods of the eastern USA rep-May 2004 FIRST VELOCIRAPTORINE, E. GULF COAST USA — KIERNAN AND SCHWIMMER 91Figure 1. cf. Saurornitholestes sp., ALMNH 2001.1. 1, Labial view, X22; 2, mesial carina with denticles, X16; 3, distal carinawith denticles, X27. Mooreville Chalk Formation, lower unnamed member, Early Campanian, RMM locality AGr-14, near OldWest Greene, Alabama.resent the latter situation (that of independent descent in placefrom basal common ancestors), rather than derivation from awestern population. It is plausible that the dromaeosaurids ofthe eastern USA had a similar origin. In this latter case, theirancestry could have been either from Asia or Europe, wheresparse remains of dromaeosaurs have been discovered (e.g.LeLeouffandBuffetaut, 1998; Allain and Taquet, 2000). Also,in this latter case, it is very unlikely that the Alabama veloci-raptorines would be congeneric with Saurornitholestes.Remains of terrestrial animals are rare in the open marinefacies of the Mooreville Chalk and, excluding volant (flying)birds and ornithocheirid pterosaurs, have previously been con-fined to fragmentary remains of crocodylians (Deinosuchusrugosus, Leidyosuchus sp. [Schwimmer, 2002]) and large tomedium-sized saurischian and ornithischian dinosaurs(Ornithomimidae insertae sedis [Baird, 1986], the iguanodon-tian Lophorhothon atopus [Langston, 1960; Lamb, 1998] andnodosaurid ankylosaurs [Langston, 1960; Lamb, 1996]).Mooreville deposition occurred in deep water in an outer-shelfenvironment (Puckett, 1996) and the discovery of a small dro-maeosaurid theropod tooth is unexpected. Schwimmer (1997)has most recently reviewed taphonomic and biogeographicmodels that may account for the distribution of dinosaurremains in the Atlantic and Gulf Coastal Plains. Dinosaurianremains in the Mooreville Chalk (as well of those of its east-ern clastic equivalent, the Blufftown Formation) most likelyresult from the fluvial transport of "bloat-and-float" carcassesoriginating in adjacent deltaic, estuarine, and marine coastalenvironments. ALMNH 2001.1 preserves delicate features(mesial and distal denticles) and doesn't appear to have suf-fered wear in a high-energy surf zone setting. Therefore, it islikely that it dropped from a passing carcass (either a dro-maeosaur itself, or the prey of a dromaeosaur), perhaps dis-lodged by scavenging sharks (Schwimmer et al. 1997), afterreaching the sea by way of a river-mouth estuary.AcknowledgementsThe authors wish to thank Charles C. Smith, GeologicalSurvey of Alabama, who examined the microflora of AGr-11;Barbara Grandstaff and Philip J. Currie, who examinedALMNH 2001.1 and shared information about unpublishedNew Jersey theropod teeth; Brian J. Witzke, who read an earlydraft of this manuscript and offered many helpful suggestions;Thomas R. Lipka, for sharing unpublished information on theArundel Clay fauna of Maryland; Richard A. Kirk, who draft-ed the cover illustration; Christine Bean and the FernbankMuseum of Natural History, for facilitating SEM imaging; andTHE MOSASAUR — THE JOURNAL OF THE DVPS Vol.7two anonymous reviewers for their thorough analysis and help-ful suggestions.ReferencesAllain, R. and P. Taquet. 2000. A new genus ofDromaeosauridae (Dinosauria, Theropoda) from theUpper Cretaceous of France. Journal of VertebratePaleontology 20(2): 404-407.Baird, D. 1986. Upper Cretaceous reptiles from the SevernFormation of Maryland. The Mosasaur 3: 63-85.Barsbold, R. 1983. Carnivorous dinosaurs from theCretaceous of Mongolia. Soviet MongolianPaleontological Expedition, Transactions 19: 118-120.Baszio, S. 1997. Systematic paleontology of isolated dinosaurteeth from the Latest Cretaceous of South Alberta,Canada. Courier Forschungsinstitut Senckenberg, Band196: 33-77.Burnham, D. A., K. L. Derstler, P. J. Currie, R. T. Bakker, Z.Zhou, and J. Ostrom. 2000. Remarkable new birdlikedinosaur (Theropoda: Maniraptoria) from the UpperCretaceous of Montana. University of KansasPaleontological Contributions 13: 1-12.Carr, T. D., T. E. Williamson, and D. R. Schwimmer. (InPress). A new genus and species of tyrannosauroid fromthe Late Cretaceous (Middle Campanian) DemopolisFormation of Alabama. Journal of VertebratePaleontology.Currie, P. J. 1995. New information of the anatomy of rela-tionships of Dromaeosaurus albertensis (Dinosauria;Theropoda). Journal of Vertebrate Paleontology 15: 576-591.. 1997. Dromaeosauridae, p. 194-195. In P. J.Currie and K. Padian (eds.), Encyclopedia ofDinosaurs. Academic Press, San Diego.. J. K. Rigby and R. E. Sloan. 1990. Theropodteeth from the Judith River Formation of southern Alberta,Canada, p. 107-125. In K. Carpenter and P.J. Currie (eds.),Dinosaur Systematics: Approaches and Perspectives.Cambridge University Press, Cambridge.Fiorillo, A. R. and P. J. Currie. 1994. Theropod teeth from theJudith River Formation (Upper Cretaceous) of south-cen-tral Montana. Journal of Vertebrate Paleontology 14: 74-80.Hooks, G. E. 1998. Systematic revision of the Protostegidae,with a redescription of Calcarichelys gemma Zangerl,1953. Journal of Vertebrate Paleontology 18(1): 85-98.Kauffman, E. G. and W. G. E. Caldwell. 1993. The WesternInterior Seaway in Space and Time, in Caldwell, W. G. E.and Kauffman, E. G., (eds.), Evolution of the WesternInterior Basin, pp. 1-30. Geological Association ofCanada, Special Paper 39.Kiernan, C. R. 2002. Stratigraphic distribution and habitatsegregation of mosasaurs in the Upper Cretaceous ofWestern and Central Alabama, with an historical overviewof mosasaur discoveries in Alabama. Journal ofVertebratePaleontology 22(1): 91-103.Kirkland, J. I., Robert Gaston, and Donald Burge. 1993. Alarge dromaeosaur (Theropoda) from the Lower Cretaceousof Eastern Utah. Hunteria 2 (10): 1-16.Lamb, J. L. 1996. Ankylosauria from the Upper Cretaceous ofAlabama. Journal of Vertebrate Paleontology 16 (3,Abstracts): 47A.. 1998. Lophorhothon, an iguanodontian, not ahadrosaur. Journal of Vertebrate Paleontology 18 (3,Abstracts): 59A.Langston, W. 1960. The vertebrate fauna of the SelmaFormation of Alabama, part VI: the dinosaurs. Fieldiana:Geology Memoirs 3(5): 315-359.Le Loeuff, J. and E. Buffetaut. 1998. A new dromaeosauridtheropod from the Upper Cretaceous of southern France.Oryctos 1: 105-112.Leidy, J. 1856. Notices of remains of extinct reptiles and fish-es, discovered by Dr. F. V. Hayden in the Bad Lands of theJudith River, Nebraska Territory. Academy of NaturalSciences of Philadelphia, Proceedings 8: 72-73.Lipka, T. R. 1998. The affinities of the enigmatic theropodsof 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 andMiddle Cretaceous Terrestrial Ecosystems. New MexicoMuseum of Natural History and Science, Bulletin 14.Albuquerque, New Mexico.Matthew, W. D. and B. Brown. 1922. The familyDeinodontidae, with notice of a new genus from theCretaceous of Alberta. Bulletin of the American Museumof'Natural History 46: 367-385.Norrell, M., JI, Q., Gao, K., Yuan, C., Zhao, Y., and Wang, L.2002. 'Modern' feathers on a non-avian dinosaur. Nature416: 36-37.Osborn, H. F. 1924. Three new Theropoda, ProtoceratopsZone, central Mongolia. American Museum of NaturalHistory Novitates 144:12.Padian, K., and Chiappe, L. M. 1997. The early evolution ofbirds. Biological Reviews of the Cambridge PhilosophicalSociety 73: 1-42.Paul, G. S. 1984. The Archosaurs: phylogenetic study, pp.175-180. In Reif, W.-E. & Westphal, F. (eds.),ThirdSymposium on Mesozoic Terrestrial Ecosystems,Tubingen 1984, Short Papers. Attempto Verlag, Tubingen.. 2001. Increasing evidence for an arboreal originof dinosaurian-avian flight, and for losses of flight in post-Yrvogel dinosaurs. Journal ofVertebrate Paleontology 21(3, Abstracts): 88A.Puckett, T. M. 1996. Ecologic atlas of Upper Cretaceousostracodes of Alabama. Geological Survey of Alabama,Monograph 14, 176 pp.Rowe, R., R. L. Cifelli, T. M. Lehman, and A. Weil. 1992. TheCampanian Terlingua Local Fauna, with a summary of ver-tebrates from the Aguja Formation, Trans-Pecos Texas.Journal ofVertebrate Paleontology 12: 472-493.May 2004 FIRST VELOCIRAPTORINE, E. GULF COAST USA — KIERNAN AND SCHWIMMER 93Schwimmer, D. R. 1997. Late Cretaceous dinosaurs in easternUSA: a taphonomic and biogeographic model of occur-rences, pp. 203-211. In D. L. Wolberg, E. Stump, and G.D. Rosenberg (eds.), Dinofest International. TheAcademy of Natural Sciences, Philadelphia.. 2002. King of the Crocodylians: ThePaleobiology of Deinosuchus. Indiana University Press,Bloomington, 221 pp.and C. R. KIERNAN. 2001. Eastern LateCretaceous theropods in North America and the crossingof the Interior Seaway. Journal of Vertebrate Paleontology21(3, Abstracts): 99A., J. D. STEWART AND G. D. WILLIAMS. 1997.Scavenging by sharks of the genus Squalicorax in the LateCretaceous of North America. Palaios 12(1): 71-83.Sissingh, W. 1977. Biostratigraphy of Cretaceous nanno-plankton of marine sediments. Geologie en Mijnbouw56(1): 37-65.Stephenson, L. W. 1914. Cretaceous deposits of the easternGulf region; and species of Exogyra from the eastern Gulfregion and the Carolinas. U.S. Geological SurveyProfessional Paper 81: 1-77.Sues, H. D. 1978. A new small theropod dinosaur from theJudith River Formation (Campanian) of Alberta, Canada.Zoological Journal of the Linnaean Society 62: 381-400.XU, X., Z. Zhou, and R. O. Prum. 2001. Branched integumen-tal structures in Sinomithosaurus and the origin of flight.Nature 410: 200-204.

A Velociraptorine tooth from Alabama and its Paleogeographic Implications

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A Velociraptorine tooth from Alabama and its Paleogeographic Implications

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