Turtles are members of the Class Reptilia, and represent the only living members of the Subclass Anapsida. The coelom and the digestive, respiratory, and urogenital systems possess both primitive characteristics of their amphibian ancestors and advanced characteristics that are unique to turtles.
Dawson, J. 1998. Digestive, respiratory, and reproductive and excretory systems. The Turtle Pages.
Kardong, K. 1998. Vertebrates:
Comparative anatomy, function, evolution. Boston: WCB/McGraw-Hill
Companies, Inc. 747 pp.
Lawson, R. 1979. The comparative
anatomy of the coelom and of the digestive and respiratory systems. In
comparative vertebrate anatomy, edited by M. H. Wake. Chicago: University of Chicago Press. 788 pp.