Hadrosaurs. David A. Eberth
Z. (ed.). 1997. Sino-Japanese Silk Road Dinosaur Expedition. China Ocean Press, Beijing, 114 pp.
Eberth, D. A., D. A. Russell, D. R. Braman, and A. L. Deino. 1993. The age of the dinosaur-bearing sediments at Tebch, Inner Mongolia, People’s Republic of China. Canadian Journal of Earth Sciences 30:2101–2106.
Li, D.-Q., M. A. Norell, K.-Q. Gao, N. D. Smith, and P. J. Makovicky. 2010. A longirostrine tyrannosauroid from the Early Cretaceous of China. Proceedings of the Royal Society Biological Sciences Series B 277:183–190.
Lü, J.-C. 1997. A new Iguanodontidae (Probactrosaurus mazongshanensis sp. nov.) from Mazongshan area, Gansu Province, China; pp. 27–47 in Z. Dong (ed.), Sino-Japanese Silk Road Dinosaur Expedition. China Ocean Press, Beijing, China.
Makovicky, P. J., D.-Q. Li, K.-Q. Gao, M. Lewin, G. M. Erickson, and M. A. Norell. 2010. A giant ornithomimosaur from the Early Cretaceous of China. Proceedings of the Royal Society Biological Sciences Series B 277:191–198.
Marsh, O. C. 1881. Principal characters of American Jurassic dinosaurs. Part V. American Journal of Science, Third Series, 21:417–423.
McDonald, A. T. 2011. The phylogeny, taxonomy, and biogeography of basal Iguanodonts (Dinosauria: Ornithischia ); pp. 101–104 in D. Braman, D. A. Eberth, D. C. Evans, and W. Taylor (compilers), Hadrosaur Symposium Abstract Volume. Royal Tyrrell Museum of Palaeontology, Drumheller, Alberta.
McDonald, A. T., P. M. Barrett, and S. D. Chapman. 2010. A new basal iguanodont (Dinosauria: Ornithischia) from the Wealden (Lower Cretaceous) of England. Zootaxa 2569:1–43.
Niu, S. W. 1987. Late Mesozoic strata of Jiuquan in Gansu. Journal of Stratigraphy 11:1–22.
Norman, D. B. 2002. On Asian ornithopods (Dinosauria: Ornithischia). 4. Probactrosaurus Rozhdestvensky, 1966. Zoological Journal of the Linnean Society 136:113–144.
Norman, D. B. 2004. Basal Iguanodontia; pp. 413–437 in D. B. Weishampel, P. Dodson, and H. Osmólska (eds.), The Dinosauria, Second Edition. University of California Press, Berkeley, California.
Parks, W. A. 1922. Parasaurolophus walkeri, a new genus and species of crested trachodont dinosaur. University of Toronto Studies, Geological Series 13:1–32.
Owen, R. 1842. Report on British fossil reptiles. Report of the British Association of Advanced Sciences 9:60–204.
Seeley, H. G. 1887. On the classification of the fossil animals commonly named Dinosauria. Proceedings of the Royal Society of London 43:165–171.
Sereno, P. C. 1986. Phylogeny of the bird-hipped dinosaurs (Order Ornithischia). National Geographic Research 2:234–256.
Sereno, P. C. 1997. The origin and evolution of dinosaurs. Annual Review of Earth and Planetary Sciences 25:435–489.
Sereno, P. C. 1998. A rationale for phylogenetic definitions, with application to the higher-level taxonomy of Dinosauria. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen 210:41–83.
Sereno, P. C. 2005. Stem Archosauria Version 1.0. TaxonSearch. Available at www.taxonsearch.org/Archive/stem-archosauria-1.0.php. Accessed January 15, 2012.
Tang, F., Z.-X. Luo, Z.-H. Zhou, H.-L. You, J. A. Georgi, Z.-L. Tang, and X.-Z. Wang. 2001. Biostratigraphy and palaeoenvironment of the dinosaur-bearing sediments in Lower Cretaceous of Mazongshan area, Gansu Province, China. Cretaceous Research 22:115–129.
You, H.-L., and D.-Q. Li. 2009. A new basal hadrosauriform dinosaur (Ornithischia: Iguanodontia) from the Early Cretaceous of northwestern China. Canadian Journal of Earth Sciences 46:949–957.
You, H.-L., D.-Q. Li, and W.-C. Liu. 2011. A new hadrosauriform dinosaur from the Early Cretaceous of Gansu Province, China. Acta Geologica Sinica 85:51–57. [English Edition]
You, H.-L., Z.-X. Luo, N. H. Shubin, L. M. Witmer, Z.-L. Tang, and F. Tang. 2003. The earliest-known duck-billed dinosaur from deposits of late Early Cretaceous age in northwest China and hadrosaur evolution. Cretaceous Research 24:347–355.
You, H.-L., K. Tanoue, and P. Dodson. 2010. A new species of Archaeoceratops (Dinosauria: Neoceratopsia) from the Early Cretaceous of the Mazongshan Area, northwestern China; pp. 59–67 in M. J. Ryan, B. J. Chinnery-Allgeier, and D. A. Eberth (eds.), New Perspectives on Horned Dinosaurs. Indiana University Press, Bloomington, Indiana.
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Postcranial Anatomy of a Basal Hadrosauroid (Dinosauria: Ornithopoda) from the Cretaceous (Cenomanian) Woodbine Formation of North Texas
Derek J. Main, Christopher R. Noto, and David B. Weishampel
ABSTRACT
New fossil material recovered from the Arlington Archosaur Site (AAS; North Arlington, Tarrant County, Texas) includes the most complete hadrosauroid (Dinosauria: Ornithopoda) recovered from the Woodbine Formation to date, and allows for a detailed study of the postcranial anatomy of a basal hadrosauroid. The depositional setting of the AAS was a delta plain, and the host facies comprise fine-grained mudstones and claystones overlying a dense peat bed. The ornithopod fossil-bearing horizon occurs within a paleosol: a clay-rich, heavily rooted histic gleysol with numerous calcareous concretions. Hadrosauroid fossils recovered include cervical, dorsal, and caudal vertebrae; ribs, a scapula and coracoid; an ilium, ischium, and pubis; and a partial juvenile femur. Most of the remains represent a single adult individual, which experienced a complex biostratinomic and fossil-diagenetic history following death. The predominance of relatively dense bones from the axial column and limbs, and disarticulation are indicative of hydraulic sorting and limited transport of the remains. The new hadrosauroid material from the Woodbine Formation demonstrates a unique mix of plesiomorphic hadrosaurid characters and derived iguanodontian features. Whereas its exact taxonomic affinity cannot be determined presently, it is expected that this specimen will prove informative in understanding hadrosauroid evolution.
INTRODUCTION
The Arlington Archosaur Site (AAS) is located in the Dallas–Fort Worth Metroplex of North Texas, within the suburban city of Arlington, in Tarrant County (Fig. 5.1). It was discovered independently in 2003 by University of Texas, Arlington, students Phil Kirchhoff and Bill Walker, and local fossil collector Art Sahlstein. Among the first fossils found and reported were crocodyliform and ornithopod dinosaur remains, leading one of us (DJM) to propose the site’s name. Unfortunately, the landowner at the time of discovery refused to grant land access. From 2003 to 2007, the 2200 acres of fossil-rich land in northern Arlington was unavailable for paleontological exploration and scientific study. It was not until a new landowner, the Huffines family, purchased the land in 2007 that formal exploration and excavation began.
Amateur fossil hunters have collected scattered dinosaur remains in the Woodbine Formation for many years, but little of this material is described in the scientific literature. Isolated skeletal remains of theropods, nodosaurid ankylosaurs, and iguanodontian ornithopods are reported by Lee (1997a) from multiple localities in the greater Dallas–Fort Worth metroplex. A proximal left femur, complete tibia, and fibula are described from a locality in the Lewisville Member of the Woodbine Formation, and a humerus and teeth have been described from the overlying Arlington Member. All of this material is assigned to indeterminate hadrosaurids (Lee, 1997a). Ornithopod tracks from the Woodbine are described by Lee (1997b), and assigned to the ichnotaxon Caririchnium protohadrosaurichnos. The best known ornithopod from the Woodbine Formation, Protohadros byrdi, was discovered at Flower Mound in 1994, and was later named in honor of its discoverer, Dallas Paleontological Society member Gary Byrd (Head, 1998). Protohadros byrdi is based on a nearly complete skull and scant postcrania from the Arlington Member of the Woodbine Formation (Head,