|
''Compsognathus'' (;〔"Compsognathus", ''Oxford English Dictionary,'' Second Edition〕 Greek ''kompsos''/κομψός; "elegant", "refined" or "dainty", and ''gnathos''/γνάθος; "jaw") is a genus of small, bipedal, carnivorous theropod dinosaurs. Members of its single species ''Compsognathus longipes'' could grow to the size of a turkey. They lived about 150 million years ago, the Tithonian age of the late Jurassic period, in what is now Europe. Paleontologists have found two well-preserved fossils, one in Germany in the 1850s and the second in France more than a century later. Today, ''C. longipes'' is the only recognized species, although the larger specimen discovered in France in the 1970s was once thought to belong to a separate species and named ''C. corallestris''. Many presentations still describe ''Compsognathus'' as "chicken-sized" dinosaurs because of the small size of the German specimen, which is now believed to be a juvenile. ''Compsognathus longipes'' is one of the few dinosaur species for which diet is known with certainty: the remains of small, agile lizards are preserved in the bellies of both specimens. Teeth discovered in Portugal may be further fossil remains of the genus. Although not recognized as such at the time of its discovery, ''Compsognathus'' is the first theropod dinosaur known from a reasonably complete fossil skeleton. Until the 1990s, it was the smallest known non-avialan dinosaur; earlier it was the closest supposed relative of the early feathered theropod dinosaur ''Archaeopteryx''. ==Description== For decades, ''Compsognathus'' were famed as the smallest dinosaurs known; the first specimen collected was around in length. However, dinosaurs discovered later, such as ''Caenagnathasia'', ''Microraptor'' and ''Parvicursor'', were even smaller. The largest ''Compsognathus'' specimen is estimated to have weighed somewhere between . ''Compsognathus'' were small, bipedal animals with long hind legs and longer tails, which they used for balance during locomotion. The forelimbs were smaller than the hindlimbs and featured three digits equipped with solid claws suited for grasping prey. Their delicate skulls were narrow and long, with tapered snouts. The skull had five pairs of fenestrae (skull openings), the largest of which was for the orbit (eye socket). The eyes were large in proportion to the rest of the skull. The lower jaw was slender and had no mandibular fenestra, a hole in the side of the lower jawbone commonly seen in archosaurs. The teeth were small but sharp, suited for its diet of small vertebrates and possibly other small animals, such as insects. Its frontmost teeth (those on the premaxilla) were unserrated, unlike those further back in the jaw which were flattened and more strongly recurved.〔Stromer, E., 1934, "Die Zähne des ''Compsognathus'' und Bemerkungen über das Gebiss der Theropoda", ''Zentralblatt für Mineralalogie, Geologie und Paläontologie, Abteilung B, Jahrgang 1934: 74–85〕 Scientists have used these dental characteristics to identify ''Compsognathus'' and its closest relatives. Reisdorf and Wuttke (2012) described the taphonomical phenomena of the German specimen of ''Compsognathus''. 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「Compsognathus」の詳細全文を読む スポンサード リンク
|