9419675 Rieppel The Sauropterygia is a major clade of fossil diapsid reptiles which successfully invaded the Mesozoic sea. The Triassic stem-group Sauropterygia provide a prime example for the study of the early evolutionary history of a major clade which involves the shift from one adaptive zone to another, i.e. the invasion of the marine habitat by reptiles. The study of the evolutionary history of this group, involving complex paleobiogeographical relations and fundamental changes of functional morphologic complexes, must be set against the background of a well corroborated pattern of phylogenetic interrelationships. Complete knowledge of sauropterygians from the Germanic Muschelkalk provides the ideal background for a revision of Triassic sauropterygian faunas outside this region including faunas from the Middle Triassic of Spain, Rumania, Israel, China, and the western United States. The phylogenetic interrelationships of stem-group Sauropterygia will be analyzed on a global scale. The resulting cladogram will be used as basis for an investigation of the palebiogeographical, paleoecological and functional morphological correlates of early sauropterygian evolution.
