摘要：

Amphisbaenians are a poorly known group of squamate reptiles with over 150 extant species in 23 genera. They live almost exclusively under loose or sandy soil in tropical to temperate areas around the world, and their anatomy is modified in many ways related to this lifestyle. Most recent studies recognize four families within Amphisbaenia—Bipedidae, Amphisbaenidae, Trogonophidae, and Rhineuridae. Only the Rhineuridae are well represented in the fossil record. Two exclusively fossil families, Hyporhinidae and Crythiosauridae, have also been recognized in some studies. In this paper, a phylogenetic study of the Amphisbaenia is presented based on morphological characters investigated in living and fossil forms. Amphisbaenian monophyly is supported, but the recent identification of the late Cretaceous Sineoamphisbaena hextabularis† as a primitive amphisbaenian is not supported. The monophyly of two of the four families of extant amphisbaenians is upheld, with one family being more inclusi

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