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''Falcarius'' is a genus of therizinosaurian dinosaur found in the Cretaceous of east-central Utah, United States. Its name is derived from the word "sickle", ''falcarius'' in Latin being a sickle cutter, which scientists have used to describe its unwieldy clawed hands. ''Falcarius'' was a 4 metres (13 ft) long, bipedal herbivore. It had a small head and a long neck and tail. The description of ''Falcarius'' (2005), following that of therizinosauroid ''Beipiaosaurus'' from the Early Cretaceous of China in 1999, clarifies the early evolution of the Therizinosauria and their relationship with the larger group of theropod dinosaurs, because ''Falcarius'' is a transitional form between older theropods and the much changed Therizinosauridae. ==History of discovery== The remains of ''Falcarius'' were first discovered in 1999 by commercial fossil collector Lawrence Walker at the Crystal Geyser Quarry site in Grand County. He informed paleontologist James Kirkland of the find, who with a team of the Utah Geological Survey from 2001 onwards began to uncover the bones that proved to be present in a two acre (8,000 square meter) area of Utah's Cedar Mountain Formation (Yellow Cat member). ''Falcarius'' thus lived approximately 126 million years ago, in the Barremian stage of the early Cretaceous Period. Two extensive bone beds were discovered, including the remains of hundreds, perhaps thousands, of individuals of the new species. The minimum number of individual animals was in 2006 estimated at three hundred.〔 In 2005 over two thousand specimens had been excavated, mostly consisting of disarticulated bones.〔 These included the remains of juvenile animals.〔Zanno, L.E. and Erickson, G.M., 2006, "Ontogeny and life history of ''Falcarius utahensis'', a primitive therizinosauroid from the Early Cretaceous of Utah", ''Journal of Vertebrate Paleontology'' 26(3): 143A〕 In 2008 a second site was reported, the Suarez Quarry, with mainly adult individuals, but of a perhaps slightly different type. In 2010 the number of specimens from the original quarry had increased to over 2700,〔Zanno, L.E., 2010, "Osteology of ''Falcarius utahensis'': Characterizing the anatomy of basal therizinosaurs", ''Zoological Journal of the Linnaean Society'' 158: 196-230〕 and was later that year reported to have risen to over three thousand.〔 While a first scientific report of ''Falcarius'' was published in 2004,〔J.I. Kirkland, L.E. Zanno, D. Deblieux, D. Smith, and S.D. Sampson, 2004, "A new, basal-most therizinosauroid (Theropoda: Maniraptora) from Utah demonstrates a pan-Laurasian distribution for Early Cretaceous (Barremian) therizinosauroids", ''Journal of Vertebrate Paleontology'' 24(3, suppl.):78A〕 and a braincase and the anterior appendicular skeleton were partly described the same year,〔Zanno, L.E., 2004, "The pectoral girdle and forelimb of a primitive therizinosauroid (Theropoda: Maniraptora): New information on the phylogenetics and evolution of therizinosaurs", ''Journal of Vertebrate Paleontology'' 24(3): 134A〕 it was not formally named until a subsequent paper was published in the May 2005 issue of the journal ''Nature''.〔Kirkland, J. I., Zanno, L. E., Sampson, S. D., Clark, J. M. & DeBlieux, D. D. (2005). "A primitive therizinosauroid dinosaur from the Early Cretaceous of Utah." ''Nature'', 435: 84-87〕 Co-authors of the study, apart from Kirkland himself, include Scott Sampson, chief curator at the University of Utah's Utah Museum of Natural History, and Lindsay Zanno, then a doctoral student at the University. Dr. Sampson is quoted as saying that this species ''"...is the missing link between predatory dinosaurs and the bizarre plant-eating therizinosaurs''". Lindsay Zanno subsequently and informally described Falcarius as "The ultimate in bizarre: a cross between an ostrich, a gorilla, and Edward Scissorhands." 〔 Nick Lane, 2009 "Life Ascending" p.230. W.W. Norton, pub. 〕 The type species is ''Falcarius utahensis''. The generic name is Latin for "sickle cutter", in reference to the large hand claws. The specific name reflects the provenance from Utah.〔 The holotype specimen, UMNH VP 15000, consists of a partial braincase. A large number of paratypes were assigned: specimens UMNH VP 12283, 12285, 12286, 12288, 12290, 12292, 12293, 12315, 12321-12329, 12343-12345, 12347-12349, 12360, 12363, 12366, 12369-12373, 12377, 12380, 12383-12384, 12386-12389, 12392-12394, 12396-12400, 12402-12404, 12406, 12410-12417, 12419-12425, 12427-12439, 12441-12443, 14530-14533, 14537-14538, 14542-14557, 14560-14565, 14568-14582, 14584-14656, 14658-14666, 14668-14670, 14672-14676, 14678-14680, 14682-14690, 14692-14699, 14701-14999 and 15001-15149. Apart from this extensive hypodigm, dozens of other bones were referred to the species.〔 A skeletal mount of ''Falcarius utahensis'', consisting of cast reconstructed elements and made by ''Gaston Design'', went on display at the Utah Museum of Natural History on 29 June 2005. The species has since been described in detail by Zanno in a series of studies, beginning with her thesis in 2006.〔Zanno, L.E., 2006, ''The pectoral girdle and forelimb of a basal therizinosauroid (Theropoda, Maniraptora) with phylogenetic and functional implications'', thesis University of Utah〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Falcarius」の詳細全文を読む スポンサード リンク
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