2009 in archosaur paleontology
2009 in archosaur paleontology GudangMovies21 Rebahinxxi LK21
The year 2009 in Archosaur paleontology was eventful. Archosaurs include the only living dinosaur group — birds — and the reptile crocodilians, plus all extinct dinosaurs, extinct crocodilian relatives, and pterosaurs. Archosaur paleontology is the scientific study of those animals, especially as they existed before the Holocene Epoch began about 11,700 years ago. The year 2009 in paleontology included various significant developments regarding archosaurs.
This article records new taxa of fossil archosaurs of every kind that have been described during the year 2009, as well as other significant discoveries and events related to paleontology of archosaurs that occurred in the year 2009.
Crurotarsans
Delfino, M.; Smith, T. (2009). "A reassessment of the morphology and taxonomic status of 'Crocodylus' depressifrons Blainville, 1855 (Crocodylia, Crocodyloidea) based on the Early Eocene remains from Belgium". Zoological Journal of the Linnean Society. 156 (1): 140–167. doi:10.1111/j.1096-3642.2008.00478.x.
Non-avian dinosaurs
= Research
=A new study on theropod furculae is published.
A "detailed description of the skull and mandible of the Chinese cerapodan ornithischian dinosaur Jeholosaurus shangyuanensis" is published.
Knoll, F.; Padian, K.; de Ricqles, A. (2009). "Ontogenetic change and adult body size of the early ornithischian dinosaur Lesothosaurus diagnosticus: Implications for basal ornithischian taxonomy". Gondwana Research. 17: 171–179. doi:10.1016/j.gr.2009.03.010.
Matthews, J. C.; Brusatte, S. L.; Williams, S. A.; Henderson, M. D. (2009). "The first Triceratops bonebed and its implications for gregarious behavior". Journal of Vertebrate Paleontology. 29 (1): 286–290. Bibcode:2009JVPal..29..286M. doi:10.1080/02724634.2009.10010382. S2CID 196608646.
Williamson, T. E.; Carr, T. D.; Williams, S. A.; Tremaine, K. (2009). "Early ontogeny of pachycephalosaurine squamosals as revealed by juvenile specimens from the Hell Creek Formation, eastern Montana". Journal of Vertebrate Paleontology. 29 (1): 291–294. Bibcode:2009JVPal..29..291W. doi:10.1671/039.029.0111. S2CID 84516840.
Bittencourt, J.S.; Kellner, A.W.A. (2009). "The anatomy and phylogenetic position of the Triassic dinosaur Staurikosaurus pricei Colbert, 1970". Zootaxa. 2079: 1–56. doi:10.11646/zootaxa.2079.1.1. S2CID 90574494.
Chin, K.; Hartman, J.H.; Roth, B. (2009). "Opportunistic exploitation of dinosaur dung: fossil snails in coprolites from the Upper Cretaceous Two Medicine Formation of Montana". Lethaia. 42 (2): 185–198. doi:10.1111/j.1502-3931.2008.00131.x.
Maidment, S.C.R.; Porro, L.B. (2009). "Homology of the palpebral and origin of supraorbital ossifications in ornithischian dinosaurs". Lethaia. 43: 95–111. doi:10.1111/j.1502-3931.2009.00172.x.
Gates, T.A.; Farke, A.A. (2009). "Biostratigraphic and biogeographic implications of a hadrosaurid (Ornithopoda: Dinosauria) from the Upper Cretaceous Almond Formation of Wyoming, USA". Cretaceous Research. 30 (5): 1157–1163. Bibcode:2009CrRes..30.1157G. doi:10.1016/j.cretres.2009.05.001.
Moratalla, J.J.; Hernán, J. (2008). "Los Cayos S y D: dos afloramientos con icnitas de saurópodos, terópodos y ornitópodos en el Cretácico Inferior del área de Los Cayos (Cornago, La Rioja, España)". Estudios Geológicos. 64 (2): 161–173. doi:10.3989/egeol.08642.043.
Taylor, M.P.; Wedel, M.J.; Naish, D. (2009). "Head and neck posture in sauropod dinosaurs inferred from extant animals". Acta Palaeontologica Polonica. 54 (2): 213–220. doi:10.4202/app.2009.0007. S2CID 7582320.
= Hadrosaur chewing study
=A study titled "Quantitative analysis of dental microwear in hadrosaurid dinosaurs, and the implications for hypotheses of jaw mechanics and feeding" is published by British paleontologists Mark Purnell, Paul Barrett and student Vince Williams. The paper examined the chewing methods and diet of hadrosaurid ("duck billed") dinosaurs from the Late Cretaceous period. The scientists analyzed hundreds of microscopic scratches on the teeth of a fossilized Edmontosaurus jaw, and believe they determined exactly how a hadrosaur broke down and ate its food, which had previously eluded researchers.
The study found hadrosaurs had a unique way of eating unlike any creature living today. In contrast to a flexible lower jaw joint prevalent in today's mammals, hadrosaurs had a unique hinge between the upper jaws and the rest of its skull. The team found the dinosaur's upper jaws pushed outwards and sideways while chewing, as the lower jaw slid against the upper teeth.
The study also concluded that hadrosaurs likely grazed on horsetails and vegetation close to the ground, rather than browsing higher-growing leaves and twigs. However, Purnell said these conclusions were less secure than the more conclusive evidence regarding the motion of teeth while chewing. Previous studies found contradictory conclusions, and the issue remains a subject of debate.
The findings were published on June 30, 2009 in the journal, The Proceedings of the National Academy of Sciences. Purnell said no previous study had ever employed this method of analyzing microscopic teeth scratches, and that the method could be used to study other areas of scientific research.
= New taxa
=Data courtesy of George Olshevky's dinosaur genera list. ~44 dinosaur genera were erected in 2009.
= Aves
=Research
Anfinson, O.A.; Lockley, M.G.; Kim, S.H.; Kim, K.S.; Kim, J.Y. (2009). "First report of the small bird track Koreanaornis from the Cretaceous of North America: implications for avian ichnotaxonomy and paleoecology" (PDF). Cretaceous Research. 30 (4): 885–894. Bibcode:2009CrRes..30..885A. doi:10.1016/j.cretres.2009.02.001.
Lockley, M.; Chin, K.; Houck, K.; Matsukawa, M.; Kukihara, R. (2009). "New interpretations of Ignotornis, the first-reported Mesozoic avian footprints: implications for the paleoecology and behavior of an enigmatic Cretaceous bird" (PDF). Cretaceous Research. 30 (4): 1041–1061. Bibcode:2009CrRes..30.1041L. doi:10.1016/j.cretres.2009.04.001.
Bell, A.; Everhart, M.J. (2009). "A new specimen of Parahesperornis (Aves: Hesperornithiformes) from the Smoky Hill Chalk (Early Campanian) of western Kansas". Transactions of the Kansas Academy of Science. 112 (1/2): 7–14. doi:10.1660/062.112.0202. S2CID 86083098.
Newly described birds
= Pterosaurs
=Lü, J. (2009). "A new non-pterodactyloid pterosaur from Qinglong County, Hebei Province of China". Acta Geologica Sinica (English Edition). 83 (2): 189–199. doi:10.1111/j.1755-6724.2009.00062.x. S2CID 247739978.
Vullo, R.; Neraudeau, D. (2009). "Pterosaur remains from the Cenomanian (Late Cretaceous) Paralic Deposits of Charentes, Western France". Journal of Vertebrate Paleontology. 29 (1): 277–282. Bibcode:2009JVPal..29..277V. doi:10.1080/02724634.2009.10010380. S2CID 197536660.
See also
2010 in archosaur paleontology
2011 in archosaur paleontology
2012 in archosaur paleontology
2013 in archosaur paleontology