Schoch Rainer R, Sues Hans-Dieter
Staatliches Museum für Naturkunde, Rosenstein 1, D-70191 Stuttgart, Germany.
Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, MRC 121, P.O. Box 37012, Washington, DC 20013-7012, USA.
Zoology (Jena). 2016 Jun;119(3):159-161. doi: 10.1016/j.zool.2016.01.004. Epub 2016 Feb 16.
The origin of turtles has been a persistent unresolved problem involving unsettled questions in embryology, morphology, and paleontology. New fossil taxa from the early Late Triassic of China (Odontochelys) and the Late Middle Triassic of Germany (Pappochelys) now add to the understanding of (i) the evolutionary origin of the turtle shell, (ii) the ancestral structural pattern of the turtle skull, and (iii) the phylogenetic position of Testudines. As has long been postulated on the basis of molecular data, turtles evolved from diapsid reptiles and are more closely related to extant diapsids than to parareptiles, which had been suggested as stem group by some paleontologists. The turtle cranium with its secondarily closed temporal region represents a derived rather than a primitive condition and the plastron partially evolved through the fusion of gastralia.
龟类的起源一直是一个长期未解决的问题，涉及胚胎学、形态学和古生物学中尚未解决的问题。来自中国晚三叠世早期（半甲齿龟）和德国中三叠世晚期（罗氏祖龟）的新化石类群，现在有助于增进对以下方面的理解：（i）龟壳的进化起源，（ii）龟类头骨的祖先结构模式，以及（iii）龟鳖目的系统发育位置。正如长期以来基于分子数据所推测的那样，龟类从双孔类爬行动物进化而来，与现存双孔类的关系比与副爬行动物更为密切，一些古生物学家曾认为副爬行动物是干群。具有次生封闭颞区的龟类颅骨代表一种衍生而非原始的状态，腹甲部分是通过腹膜肋的融合进化而来的。
