LITERATURE CITED
- Balanoff, A. M., X. Xu, Y. Kobayashi, Y. Matsufune, and M. A. Norell. 2009. Cranial osteology of the theropod dinosaur Incisivosaurus gauthieri (Theropoda: Oviraptorosauria). American Museum Novitates 3651:1–35.
- Barrett, P. M. 2005. The diet of ostrich dinosaurs (Theropoda: Ornithomimosauria). Palaeontology 48:347–358.
- Barsbold, R. 1983. Carnivorous dinosaurs from the Cretaceous of Mongolia. Joint Soviet-Mongolian Expedition, Transactions 19:5–119. [Russian]
- Barsbold, R., and A. Perle. 1980. Segnosauria, a new infraorder of carnivorous dinosaurs. Acta Palaeontologica Polonica 25:185–195.
- Bever, G. S., and M. A. Norell. 2009. The perinate skull of Byronosaurus (Troodontidae) with observations on the cranial ontogeny of paravian theropods. American Museum Novitates 3657:1–51.
- Brusatte, S. L., and P. C. Sereno. 2007. A new species of Carcharodontosaurus (Dinosauria: Theropoda) from the Cenomanian of Niger and a revision of the genus. Journal of Vertebrate Paleontology 27:902–916.
- Clark, J. M., T. Maryanska, and R. Barsbold. 2004. Therizinosauroidea; pp. 151–164 in D. B. Weishampel, P. Dodson, and H. Osmólska (eds.), The Dinosauria, second edition. University of California Press, Berkeley, California.
- Clark, J. M., M. A. Norell, and T. Rowe. 2002. Cranial anatomy of Citipati osmolskae (Theropoda, Oviraptorosauria), and a reinterpretation of the holotype of Oviraptor philoceratops. American Museum Novitates 3364:1–24.
- Clark, J. M., A. Perle, and M. A. Norell. 1994. The skull of Erlicosaurus andrewsi, a Late Cretaceous “Segnosaur” (Theropoda: Therizinosauridae) from Mongolia. American Museum Novitates 3115:1–39.
- Coria, R. A., and P. J. Currie. 2002. The braincase of Giganotosaurus carolinii (Dinosauria: Theropoda) from the Upper Cretaceous of Argentina. Journal of Vertebrate Paleontology 22:802–811.
- Currie, P. J. 1985. Cranial anatomy of Stenonychosaurus inequalis (Saurischia, Theropoda) and its bearing on the origin of birds. Canadian Journal of Earth Sciences 22:1643–1658.
- Currie, P. J., and X.-J. Zhao. 1993a. A new troodontid (Dinosauria, Theropoda) braincase from the Dinosaur Park Formation (Campanian) of Alberta. Canadian Journal of Earth Sciences 30:2231–2247.
- Currie, P. J., and X.-J. Zhao. 1993b. A new large theropod (Dinosauria, Theropoda) from the Jurassic of Xinjiang, People's Republic of China. Canadian Journal of Earth Sciences 30:2037–2081.
- Davit-Béal, T., A. S. Tucker, and J.-Y. Sire. 2009. Loss of teeth and enamel in tetrapods: fossil record, genetic data and morphological adaptations. Journal of Anatomy 214:477–501.
- Eddy, D. R., and J. A. Clarke. 2011. New information on the cranial anatomy of Acrocanthosaurus atokensis and its implications for the phylogeny of Allosauroidea (Dinosauria: Theropoda). PLoS ONE 6:e17932. doi: 10.1371/journal.pone.0017932.
- Gauthier, J. A. 1986. Saurischian monophyly and the origin of birds; pp. 1–55 in K. Padian (ed.), The Origin of Birds and the Evolution of Flight. Memoirs of the California Academy of Sciences 8.
- Hieronymus, T., and L. M. Witmer. 2010. Homology and evolution of avian compound rhamphothecae. Auk 127:590–604.
- Holliday, C. M. 2009. New insights into dinosaur jaw muscle anatomy. The Anatomical Record 292:1246–1265.
- Hu, D., X. Xu, L. Hou, and C. Sullivan. 2012. A new enantiornithine bird from the Lower Cretaceous of Western Liaoning, China, and its implications for early avian evolution. Journal of Vertebrate Paleontology 32:639–645.
- Huene, F. von. 1914. Das natürliche System der Saurischia. Zentralblatt für Mineralogie, Geologie, und Paläontologie, Series B 1914:154–158.
- Ji, Q., P. J. Currie, M. A. Norell, and S.-A. Ji. 1998. Two feathered dinosaurs from northeastern China. Nature 393:753–761.
- Kirkland, J. I., D. Smith, and D. Wolfe. 2005a. Holotype braincase of Nothronychus mckinleyi Kirkland and Wolfe, 2001 (Theropoda, Therizinosauridae); pp. 87–96 in K. Carpenter (ed.), The Carnivorous Dinosaurs. Indiana University Press, Bloomington and Indianapolis, Indiana.
- Kirkland, J. I., L. E. Zanno, S. D. Sampson, J. M. Clark, and D. D. Deblieux. 2005b. A primitive therizinosauroid dinosaur from the Early Cretaceous of Utah. Nature 435:84–87.
- Knutsen, E. M. 2007. Beak morphology in extant birds with implications on beak morphology in ornithomimids. Masters thesis, University of Oslo, Oslo, Norway, 44 pp.
- Kobayashi, Y., and R. Barsbold. 2005a. Reexamination of a primitive ornithomimosaur, Garudimimus brevipes Barsbold, 1981 (Dinosauria: Theropoda), from the Late Cretaceous of Mongolia. Canadian Journal of Earth Sciences 42:1501–1521.
- Kobayashi, Y., and R. Barsbold. 2005b. Anatomy of Harpymimus okladnikovi Barsbold and Perle 1984 (Dinosauria; Theropoda) of Mongolia; pp 97–126 in K. Carpenter (ed.), The Carnivorous Dinosaurs. Indiana University Press, Bloomington and Indianapolis, Indiana.
- Kobayashi, Y., and J. C. Lü. 2003. A new ornithomimid dinosaur with gregarious habits from the Late Cretaceous of China. Acta Palaeontologica Polonica 48:235–259.
- Kundrat, M., A. R. I. Cruickshank, T. W. Manning, and J. Nudds. 2008. Embryos of therizinosauroid theropods from the Upper Cretaceous of China: diagnosis and analysis of ossification patterns. Acta Zoologica 89:231–251.
- Lautenschlager, S. 2013. Cranial myology and bite force performance of Erlikosaurus andrewsi: a novel approach for digital muscle reconstructions. Journal of Anatomy 222:260–272.
- Lautenschlager, S. 2014. Palaeontology in the third dimension: a comprehensive guide for the integration of three-dimensional content in publications. Paläontologische Zeitschrift 88:111–121.
- Lautenschlager, S., E. J. Rayfield, A. Perle, L. E. Zanno, and L. M. Witmer. 2012. The endocranial anatomy of Therizinosauria and its implications for sensory and cognitive function. PLoS ONE 7:e52289. doi: 10.1111/joa.12000.
- Li, D., C. Peng, H. You, M. C. Lamanna, J. D. Harris, K. J. Lacovara, and J. Zhang. 2007. A large therizinosauroid (Dinosauria: Theropoda) from the Early Cretaceous of Northwestern China. Acta Geologica Sinica 81:539–549.
- Louchart, A., and L. Viriot. 2011. From snout to beak: the loss of teeth in birds. Trends in Ecology and Evolution 26:663–673.
- Madsen, J. H., Jr. 1976. Allosaurus fragilis: a revised osteology. Utah Geological Survey Bulletin 109:1–163.
- Makovicky, P. J., and M. A. Norell. 2004. Troodontidae; pp. 184–195 in D. B. Weishampel, P. Dodson, and H. Osmólska (eds.), The Dinosauria, second edition. University of California Press, Berkeley, California.
- Makovicky, P. J., Y. Kobayashi, and P. J. Currie. 2004. Ornithomimosauria; pp. 137–150 in D. B. Weishampel, P. Dodson, and H. Osmólska (eds.), The Dinosauria, second edition. University of California Press, Berkeley, California.
- Makovicky, P. J., M. A. Norell, J. M. Clark, and T. Rowe. 2003. Osteology and relationships of Byronosaurus jaffei (Theropoda: Troodontidae). American Museum Novitates 3402:1–32.
- Maleev, E. A. 1954. A new turtle-like reptile in Mongolia. Priroda 954:106–108. [Russian]
- Marsh, O. C. 1881. Principal characters of American Jurassic dinosaurs, Part V. American Journal of Science, Series 3 21:417–423.
- Morhardt, A., M. Bonnan, and T. Keillor. 2009. Dinosaur smiles: correlating premaxilla, maxilla, and dentary foramina counts with extra-oral structures in amniotes and its implications for dinosaurs. Journal of Vertebrate Paleontology, Program and Abstracts 29:152A.
- Nicholls, E. L., and A. P. Russell. 1985. Structure and function of the pectoral girdle and forelimb of Struthiomimus altus (Theropoda: Ornithomimidae). Palaeontology 28:643–677.
- Norell, M. A., P. J. Makovicky, and P. J. Currie. 2001. The beak of ostrich dinosaurs. Nature 412:873–874.
- Norell, M. A., J. M. Clark, A. H. Turner, P. J. Makovicky, R. Barsbold, and T. Rowe. 2006. A new dromaeosaurid theropod from Ukhaa Tolgod (Ömnögov, Mongolia). American Museum Novitates 3545:1–51.
- Norell, M. A., P. J. Makovicky, G. S. Bever, A. M. Balanoff, J. M. Clark, R. Barsbold, and T. Rowe. 2009. A review of the Mongolian Cretaceous Dinosaur Saurornithoides (Troodontidae: Theropoda). American Museum Novitates 3654:1–63.
- O’Connor, J. K., and L. M. Chiappe. 2011. A revision of enantiornithine (Aves: Ornithothoraces) skull morphology. Journal of Systematic Palaeontology 9:135–157.
- Osmolska, H., E. Roniewicz, and R. Barsbold. 1972. A new dinosaur, Gallimimus bullatus n. gen., n. sp. (Ornithomimidae) from the Upper Cretaceous of Mongolia. Palaeontologia Polonica 27:103–143.
- Owen, R. 1842. Report on British fossil reptiles, Part II. Reports of the British Association for the Advancement of Science 11:60–204.
- Paul, G. S. 1984. The segnosaurian dinosaurs: relics of the prosauropod-ornithischian transition? Journal of Vertebrate Paleontology 4:507–515.
- Perez-Moreno, B. P., J. L. Sanz, A. Buscalioni, J. J. Moratalla, F. Ortega, and D. Rasskin-Gutman. 1994. A unique multitoothed ornithomimosaur dinosaur from the Lower Cretaceous of Spain. Nature 370:363–367.
- Perle, A. 1979. Segnosauridae – a new family of theropods from the Late Cretaceous of Mongolia. Joint Soviet-Mongolian Expedition, Transactions 8:45–55. [Russian]
- Perle, A. 1981. A new segnosaurid from the Upper Cretaceous of Mongolia. Joint Soviet-Mongolian Paleontological Expedition, Transactions 15:59–50. [Russian]
- Pu, H.-Y., Y. Kobayashi, J. Lü, L. Xu, Y. Wu, H. Chang, J. Zhang, and S. Jia. 2013. An unusual basal therizinosaur dinosaur with an ornithischian dental arrangement from northeastern China. PLoS ONE 8:e63423. doi: 10.1371/journal.pone.0063423.
- Russell, D. A. 1972. Ostrich dinosaurs from the Late Cretaceous of Western Canada. Canadian Journal of Earth Sciences 9:375–402.
- Russell, D. A. 1997. Therizinosauria; pp. 729–730 in P. J. Currie and K. Padian (eds.), Encyclopedia of Dinosaurs. Academic Press, San Diego.
- Russell, D. A., and Z.-M. Dong. 1993. The affinities of a new theropod from the Alxa-Desert, Inner Mongolia, People's Republic of China. Canadian Journal of Earth Sciences 30:2107–2127.
- Sampson, S. D., and L. M. Witmer. 2007. Craniofacial anatomy of Majungasaurus crenatissimus (Theropoda: Abelisauridae) from the Late Cretaceous of Madagascar; pp. 32–102 in S. D. Sampson and D. W. Krause (eds.), Majungasaurus crenatissimus (Theropoda: Abelisauridae) from the Late Cretaceous of Madagascar. Society of Vertebrate Paleontology, Memoir 8.
- Seeley, H. G. 1887. On the classification of the fossil animals commonly named Dinosauria. Proceedings of the Royal Society of London 43:165–171.
- Senter, P., and J. M. Parrish. 2005. Functional analysis of the hands of the theropod dinosaur Chirostenotes pergracilis: evidence for an unusual paleoecological role. PaleoBios 25:9–19.
- Shuvalov, V. E. 2000. The Cretaceous stratigraphy and palaeobiogeography of Mongolia; pp. 256–278 in M. J. Benton, M. A. Shishkin, D. M. Unwin, and E. N. Kuroschkin (eds.), The Age of Dinosaurs in Russia and Mongolia. Cambridge University Press, Cambridge, U.K.
- Smith, D. K., L. E. Zanno, R. K. Sanders, D. D. Deblieux, and J. I. Kirkland. 2011. New information on the braincase of the North American therizinosaurian (Theropoda, Maniraptora) Falcarius utahensis. Journal of Vertebrate Paleontology 31:387–404.
- Snively, E., and A. P. Russell. 2007. Functional variation of neck muscles and their relation to feeding style in tyrannosauridae and other large theropod dinosaurs. The Anatomical Record 290:934–957.
- Witmer, L. M. 1997. Craniofacial air sinus systems; pp. 151–159 in P. J. Currie and K. Padian (eds.), The Encyclopedia of Dinosaurs. Academic Press, New York.
- Xu, X., and X.-L. Wang. 1999. A therizinosauroid dinosaur with integumentary structures from China. Nature 399:350–354.
- Xu, X., and X.-C. Wu. 2001. Cranial morphology of Sinornithosaurus millenii Xu et al. 1999 (Dinosauria: Theropoda: Dromaeosauridae) from the Yixian Formation of Liaoning, China. Canadian Journal of Earth Sciences 38:1739–1752.
- Xu, X., X. Zheng, and H. You. 2009a. A new feather type in a nonavian theropod and the early evolution of feathers. Proceedings of the National Academy of Sciences of the United States of America 106:832–834.
- Xu, X., M. A. Norell, X.-L. Wang, P. J. Makovicky, and X.-C. Wu. 2002b. A basal troodontid from the Early Cretaceous of China. Nature 415:780–784.
- Xu, X., X.-H. Zhang, P. C. Sereno, X. Zhao, X.-W. Kuang, J. Han, and L. Tan. 2002a. A new therizinosauroid (Dinosauria, Theropoda) from the Upper Cretaceous Iren Danasu Formation of Nei Mongol. Vertebrata PalAsiatica 3:228–240.
- Xu, X., J. M. Clark, J. Mo, J. Choiniere, C. A. Forster, G. M. Erickson, D. W. E. Hone, C. Sullivan, D. A. Eberth, S. Nesbitt, Q. Zhao, R. Hernandez, C.-K. Jia, F.-L. Han, and Y. Guo. 2009b. A Jurassic ceratosaur from China helps clarify avian digital homologies. Nature 459:940–944.
- Zanno, L. E. 2006. The pectoral girdle and forelimb of the primitive therizinosauroid Falcarius utahensis (Theropoda, Maniraptora): analyzing evolutionary trends within Therizinosauroidea. Journal of Vertebrate Paleontology 26:635–650.
- Zanno, L. E. 2010a. Osteology of Falcarius utahensis (Dinosauria: Theropoda): characterizing the anatomy of basal therizinosaurs. Zoological Journal of the Linnean Society 158:196–230.
- Zanno, L. E. 2010b. A taxonomic and phylogenetic re-evaluation of Therizinosauria (Dinosauria: Maniraptora). Journal of Systematic Palaeontology 8:503–543.
- Zanno, L. E., and P. J. Makovicky. 2011. Herbivorous ecomorphology and specialization patterns in theropod dinosaur evolution. Proceedings of the National Academy of Sciences of the United States of America 108:232–237.
- Zanno, L. E., D. D. Gillette, L. B. Albright, and A. L. Titus. 2009. A new North American therizinosaurid and the role of herbivory in ‘predatory’ dinosaur evolution. Proceedings of the Royal Society B 276:3505–3511.
- Zhang, X.-H., X. Xu, X. Zhao, P. C. Sereno, X.-W. Kuang, and L. Tan. 2001. A long-necked therizinosauroid dinosaur from the Upper Cretaceous Iren Dabasu Formation of Nei Mongol, People's Republic of China. Vertebrata PalAsiatica 4:282–290.
- Submitted August 3, 2013; revisions received December 4, 2013; accepted December 8, 2013. Handling editor: Paul Barrett.