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''Machimosaurus'' is an extinct genus of teleosaurid crocodyliform from the Late Jurassic (Kimmeridgian and Tithonian). The type species, ''Machimosaurus hugii'', was found in Switzerland. Other fossils have been found in England, France, Germany, Portugal and Switzerland.〔Steel R. 1973. ''Crocodylia. Handbuch der Paläoherpetologie, Teil 16''. Stuttgart: Gustav Fischer Verlag,116 pp.〕〔Mateus, O. 2013. Crocodylomorphs from the Mesozoic of Portugal and a new skull of eusuchian from the Late Cretaceous. Abstract book of Hwaseong International Dinosaurs Expedition Symposium, South Korea, pp: 66-68.〕 ''Machimosaurus'' was not only both the largest teleosaurid and thalattosuchian, but with a length exceeding 9 metres (skull length 1.5 m), it was the largest crocodyliform of the Jurassic.〔 ==Discovery and species== Christian Erich Hermann von Meyer in 1837 named isolated conical, blunt teeth with numerous longitudinal lines from Switzerland, ''Madrimosaurus hugii''. However, in 1838, realising he had made misspelled the name, he emended ''Madrimosaurus'' to ''Machimosaurus''.〔 The teeth of ''Machimosaurus'', with their rounded, blunt apex and stout morphology make them characteristic and easily identifiable compared to other teleosaurid teeth.〔Vignaud P. 1997. La morphologie dentaire des Thalattosuchia (Crocodylia, Mesosuchia). ''Palaeovertebrata'' 26 (1/4): 35-59.〕 The type species, ''M. hugii'', is known from the Kimmeridgian of Portugal, Spain, and Switzerland.〔 ''Machimosaurus ferox'' and ''M. interruptus'' were previously considered junior synonyms of ''M. hugii'',〔Krebs B. 1967. Der Jura-Krokodilier Machimosaurus H. v. Meyer. ''Paläontologische Zeitschrift'' 41: 46–55.〕〔Buffetaut E. 1982. Le crocodilien Machimosaurus VON MEYER (Mesosuchia, Teleosauridae) dans le Kimmeridgien de l’Ain. ''Bulletin trimestrielle Societe de la géologique Normandie et Amis du Museum, Havre'' 69 (1/2): 17-27.〕 but have been recently considered possible synonyms of ''Machimosaurus mosae''.〔 Krebs (1967),〔 considered ''M. mosae'' (Lienard, 1876) to be a junior synonym of ''M. hugii'', but is considered a second valid species of the genus based on a nearly complete skeleton found from the late Kimmeridgian of France.〔〔Hua S, Vasse D, Buffetaut E, Martin M, Mazin J-M, Vadet A. 1993. Un squelette de ''Machimosaurus mosae Sauvage et Lienard,'' 1879 (Crocodylia, Thalattosuchia) dans le Kimméridgien du Boulonnais. ''Comptes rendus de l'Académie des sciences. Série 2, Mécanique, Physique, Chimie, Sciences de l'univers, Sciences de la Terre'' 317 (6):851-856〕 Two species also placed within ''Machimosaurus'' are ''M. bathonicus'' and ''M. rigauxi'', from the Bathonian of France.〔Sauvage H-E. 1874. Mémoire sur les dinosauriens et les crocodiliens des terrains jurassiques de Boulogne-sur-Mer. ''Mémoires de la Société Géologique de France, série 2'' 10 (2):1-57.〕 However, these are gracile species, lacking the characteristic blunted teeth of ''Machimosaurus'', and are probably referable to ''Steneosaurus''.〔 Mark Young and his colleagues 〔Young, M. T., Hua S., Steel L., Foffa D., Brusatte S. L., Thüring S., Mateus O., Ignacio-Ruiz Omeñaca J., Lepage Y., Havilk P., & Andrade M. B. (2014). Revision of the Late Jurassic teleosaurid genus Machimosaurus (Crocodylomorpha, Thalattosuchia). Royal Society Open Science. 1(140222), 1-42.〕〔Young, M. T., Hua S., Steel L., Foffa D., Brusatte S. L., Thüring S., Mateus O., Ruiz-Omeñaca J. I., Havlik P., Lepage Y., & de Andrade M. B. (2015). Addendum to ‘Revision of the Late Jurassic teleosaurid genus Machimosaurus (Crocodylomorpha, Thalattosuchia)’. Royal Society Open Science. 2, , Number 2〕 made a detailed revision of the genus and recognized four species: ''M. hugii'', ''M. mosae'', ''M. nowackianus'' from Harrar, Ethiopia, and a new species, ''Machimosaurus buffetauti''. They hypothesize that Machimosaurus may have been analogous to the Pliocene–Holocene genus Crocodylus in having one large-bodied taxon suited to traversing marine barriers and additional, geographically limited taxa across its range. The fossilised anterior portion of the lower jaw from the Late Jurassic (Oxfordian or Kimmeridgian) of Ethiopia referred to the pliosaur ''Simolestes nowackianus'', is in fact a large species of ''Machimosaurus''.〔Bardet N, Hua S. 1996. ''Simolestes nowackianus'' HUENE, 1938 from the Late Jurassic of Ethiopia is a teleosaurid crocodile, not a pliosaur. ''Neues Jahrbuch für Geologie und Paläontologie Monatschefte'' 1996: 65-71.〕 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「Machimosaurus」の詳細全文を読む スポンサード リンク
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