Abstract: A nearly complete skeleton of a choristodere is described and Ikechosaurus pijiagouensis sp. nov. is erected on the basis of this specimen. This new species is distinguished from other species of the genus Ikechosaurus by the following features : the jugal extends anteriorly to about the middle of the lacrymal ; the interorbital bar is narrower than the diameter of the orbit ; the postorbital separated from the postfrontal ; the anterior process of the iliac blade is less pronounced ; there is no distinct neck region between the acetabulum and iliac blade ; the ratio of epipodials to the propodials are relatively small. The morphology of this specimen reveals that certain characters like the fusion of the postfrontal and postorbital and the lack of a prominent postorbital process of the jugal cannot be used to diagnose the Simoedosaridae and Champsosauridae. Comparison with other choristoderes suggests that Ikechosaurus is more closely re2 lated to Tchoiria than with Champsosaurus and Simoedosaurus.

摘要： 伊克昭龙( Ikechosaurus) 是一类长吻的离龙类,以前根据内蒙古的材料建立了孙氏种( I.sunailinae Sigogneau-Russell , 1981) 及高氏种( I. gaoi Lüet al. , 1999) 。根据蒙古的材料建立的Tchoiria magnus Efimov , 1979 也于1983 年被原作者归入本属。本文记述了辽宁义县皮家沟九佛堂组新发现的一个近于完整保存的骨架(中国科学院古脊椎动物与古人类研究所标本编号: IVPP V 13283) , 并建立一新种:皮