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''Efraasia'' (pronounced "E-FRAHS-ee-A") is a genus of basal sauropodomorph dinosaur. It was a herbivore which lived during the middle Norian stage of the Late Triassic, around 210 million years ago, in what is now Germany. It was named in 1973 after Eberhard Fraas, who during the early twentieth century collected what were the original type specimens. The specimens were at first assigned to three already existing genera and so became divided among three separate species: ''Teratosaurus minor'', ''Sellosaurus fraasi'' and ''Paleosaurus diagnosticus''. In 2003 these were combined into a single valid species: ''Efraasia minor''. ''Efraasia'' was a lightly built, medium-sized sauropodomorph, about long. ==Discovery and naming== ''Efraasia'' has had a complicated taxonomic history involving several genera and species. Material now known under ''Efraasia'' first came to light after Albert Burrer, ''Hofsteinmetzmeister'' ("Court master stonemason") at Maulbronn, in 1902 began to exploit the ''Weiße Steinbruch'', a quarry near Pfaffenhofen in Württemberg. To reach the layer of hard white sandstone Burrer wanted to use for his building projects a thick overburden of softer marl had to be removed. Many vertebrate fossils proved to be present in it. This stratum was part of the Stubensandstein Member of the lower Löwenstein Formation, dating to the Norian. From 1906 until 1914 when the quarry closed, Burrer donated the finds to paleontologist Professor Fraas of the ''königliche Stuttgarter Naturalienkabinett''. A specimen of a basal sauropodomorph, SMNS 11838, was first described by Friedrich von Huene in 1907–1908 and named as a new species of ''Teratosaurus'': ''T. minor''. At the time, ''Teratosaurus'' was thought to be a theropod dinosaur; it was only established as a rauisuchian non-dinosaur in the 1980s. The specific name referred to the fact that the specimen was smaller than ''Teratosaurus suevicus''. The fossils consisted of a few vertebrae from the hip, the right hindlimb, and a pubic bone. Elsewhere in the same publication he gave the name ''Sellosaurus fraasi'' to a partial skeleton, SMNS 12188-12192, from slightly older rocks of the same formation, as a second species of his new genus ''Sellosaurus'' (the genus is today considered to be a synonym of ''Plateosaurus'').〔F. v. Huene, 1908, ''Die Dinosaurier der Europäischen Triasformation mit berücksichtigung der Ausseuropäischen vorkommnisse''. Geologische und Palaeontologische Abhandlungen Suppl. 1(1): 1-419〕 In 1912, Eberhard Fraas reported on two partial skeletons, SMNS 12667 and SMNS 12684 collected in 1909, which he assigned to a new species of ''Thecodontosaurus'': ''T. diagnosticus''.〔E. Fraas, 1912, "Die schwäbischen Dinosaurier", ''Jahreshefte des Vereins für Vaterländische Naturkunde in Württemberg'' 68: 56-57〕 He would never describe them due to his failing health, and thus this name remained a ''nomen nudum''. Von Huene adopted the specific name years later, after Fraas' death, redescribing Fraas' specimens as ''Paleosaurus (?) diagnosticus'' in 1932.〔Huene, F. von, 1932, ''Die fossile Reptil-Ordnung Saurischia, ihre Entwicklung und Geschichte: Monographien zur Geologie und Palaeontologie'', 1e Serie, Heft 4, pp. 1-361〕 The question mark indicates that von Huene considered the reference as provisional only. In 1959 Oskar Kuhn pointed out that the name ''Paleosaurus'' Riley & Stutchbury 1836 was preoccupied and renamed the genus ''Palaeosauriscus''.〔Kuhn, O., 1959, "Ein neuer Microsaurier aus dem deutschen Rotliegenden", ''Neues Jahrbuch für Geologie und Palaeontologie. Monatshefte'' 9: 424-426〕 Allen Charig in 1967 was the first to use the combination ''Palaeosauriscus diagnosticus'' for the German material.〔Appleby, R.M.; Charig, A.J., Cox, C.B.; Kermack, K.A. & Tarlo, L.B.H., 1967, "Reptilia", In: (Harland, B. e.a. ed.) ''The Fossil Record'', Geological Society of London, pp 695-731〕 However, the new generic name was itself a junior homonym of ''Palaeosauriscus fraserianus'' Cope 1878. Peter Galton reassigned Fraas' specimens to the new genus ''Efraasia'' in 1973, because ''Palaeosaurus'', apart from the homonymy problems, was a nondiagnostic tooth genus. The generic name was a contraction of "E. Fraas". The new species name combination thus became ''Efraasia diagnostica''.〔P.M. Galton, 1973, "On the anatomy and relationships of ''Efraasia diagnostica'' (Huene) n.gen., a prosauropod dinosaur (Reptilia: Saurischia) from the Upper Triassic of Germany", ''Paläontologische Zeitschrift'' 47(3/4): 229-255〕 However, Galton and Robert Bakker later (1985) recommended that ''Efraasia'' be considered a junior synonym of another prosauropod, ''Sellosaurus gracilis''.〔Galton, P.M. & Bakker, R.T., 1985, "The cranial anatomy of the prosauropod dinosaur "Efraasia diagnostica", a juvenile individual of ''Sellosaurus gracilis'' from the Upper Triassic of Nordwürttemberg, West Germany", ''Stuttgarter Beiträge zur Naturkunde B'', 117: 1-15〕 In 2003, Adam Yates published a study incorporating these and other fossils from the Late Triassic of Germany.〔 *A.M. Yates, 2003, "The species taxonomy of the sauropodomorph dinosaurs from the Löwenstein Formation (Norian, Late Triassic) of Germany", ''Palaeontology'' 46(2): 317-337〕 He found that the "Sellosaurus" material fell into two clusters. One included the original ''Sellosaurus gracilis'', which he assigned to ''Plateosaurus'' as ''P. gracilis''. The other included "Teratosaurus" ''minor'', "Sellosaurus" ''fraasi'', and "Palaeosaurus" ''diagnosticus''. ''Efraasia'' was the oldest valid generic name for these fossils. The specific name could not be determined as simply, as both ''Teratosaurus minor'' and ''Sellosaurus fraasi'' had first appeared in von Huene's 1908 book. Because the former name had page priority, Yates chose ''minor'' as the specific name, providing for the type species ''Teratosaurus minor'' the new combination ''Efraasia minor'', which is thus the single valid species name of the taxon.〔 Yates did not take into account two other species based by von Huene on very fragmentary German basal sauropodomorph material, ''Teratosaurus trossingensis'' and ''Thecondontosaurus hermannianus'', though Galton had considered them junior synonyms of ''Efraasia diagnostica'' in 1990.〔Galton, P.M. 1990. "Basal Sauropodomorpha-Prosauropoda". Pp. 320-344 in: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.), ''The Dinosauria''. University of California Press, Berkeley〕 Apart from the specimens mentioned above, mostly consisting of rather complete skeletons preserved in large slabs, though not fully prepared from the rock matrix, several other fossils have been found. Together they allow for a good impression of what the animal looked like. 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「Efraasia」の詳細全文を読む スポンサード リンク
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