Un taxon-frère pour Testudinata?

23 pages, 8 figures, 4 planchesKaosaurus spiniferus species was described for the first time by Michaut [2002] then classified like Testudines sister-group (Kané and Michaut [2007]) on the basis of several characters interpreted as synapomorphies of the group {Kaosaurus ; Testudines}. These characters are, in a first hand, the animal carapaces and in the other hand, these related to jaws : development of a beak, followed by a progressive loss of the dentition. The new discovery of the Testudinata Odontochelys semitestacea (Li et al. [2008]) shows that the second group of synapomorphies is actually a convergence. This will change the hypothesis regarding Kaosaurus spiniferus as being the sister-group of Testudinata. This article suggests an update of our last publications. The hypothese will be reviewed then re-set in the taxinomic framework of Archosauria, based on Testudines Zardoya and Meyer [2001] and Meyer and Zardoya [2003] works. An additional paragraph compares cranial structures. The article ends with ecological considerations, with a comparison of ecological niches occupied by carapace animals and their structures