Testudinata

Belongs within: Neodiapsida.
Contains: Casichelydia.

The Testudinata are the turtles and tortoises, a clade of reptiles unmistakeable through the enclosure of the body in a bony shell. The shell incorporates the ribcage of the animal, and the shoulder girdle has become enclosed within the ribcage. The relationships of testudinates to other reptiles remain rather uncertain due to their highly modified anatomy. The most commonly supported views are a relationship to the anapsid procolophonians or to the diapsid sauropterygians.

The earliest known turtles come from the Late Triassic (Middle Triassic if the fragment Priscochelys comes from a testudinate) with the basalmost testudinate Odontochelys lacking a developed carapace, though the plastron was already present. Odontochelys was likely an aquatic form, inhabiting marginal river delta habitats (Li et al. 2008). As well as the presence of a carapace, testudinates other than Odontochelys are united by the absence of teeth on the maxilla, premaxilla and dentary, which are covered by a horny beak (Gaffney & Meylan 1988). The Late Triassic Proganochelys retained a series of flattened teeth on the roof of the mouth. Proganochelys quenstedti is known from Norian deposits of Germany and Switzerland. It possesses a relatively long tail with a club developed at the end. Authors have disagreed whether Proganochelys was likely semi-aquatic or fully terrestrial.

<==Testudinata [Chelonia, Proganochelydia]
    |--Odontochelys Li, Wu et al. 2008 [Odontochelyidae]LW08
    |    `--*O. semitestacea Li, Wu et al. 2008LW08
    `--+--CasichelydiaGM88
       `--Proganochelys Baur 1887LW08, D07
            |--P. quenstedti Baur 1887B93
            `--P. ruchaeB93

Testudinata incertae sedis:
  Plastomenus Cope 1872C77
    |--P. communis Cope 1875C77
    |--P. corrugatus Cope 1875C77
    |--P. fractus Cope 1875C77
    |--P. lachrymalis Cope 1874C77
    |--P. multifoveatus Cope 1872 [incl. P. catenatus Cope 1875]C77
    |--P. oedemiusC77
    |--P. serialis Cope 1877C77
    |--P. thomasiiC77
    `--P. trionychoidesC77
  Scaptochelys agassiziiAA87
  Anglocetus beatsoni Tarlo 1964BM78
  Kallokibotion [Kallokibotiidae]PST99
    `--K. bajazidi Nopcsa 1923PST99
  Cheirogaster gymnesica Bate 1914RB05, BG-PQ-C02
  Solnhofia parsoniR93
  SandowinaLW08
  Australochelys africanusLW08, JPG04
  ManchurochelysD07
    |--M. liaoxiensisZBH03
    `--M. manchuensisZBH03
  Thalassochelys carettaW06

*Type species of generic name indicated

References

[AA87] Avise, J. C., J. Arnold, R. M. Ball, E. Bermingham, T. Lamb, J. E. Neigel, C. A. Reeb & N. C. Saunders. 1987. Intraspecific phylogeography: the mitochondrial DNA bridge between population genetics and systematics. Annual Review of Ecology and Systematics 18: 489–522.

[BG-PQ-C02] Bailon, S., J. Garcia-Porta & J. Quintana-Cardona. 2002. Première découverte de Viperidae (Reptilia, Serpentes) dans les îles Baléares (Espagne): des vipères du Néogène de Minorque. Description d’une nouvelle espèce du Pliocène. Comptes Rendus Palevol 1: 227–234.

[BM78] Barnes, L. G., & E. Mitchell. 1978. Cetacea. In: Maglio, V. J., & H. B. S. Cooke (eds) Evolution of African Mammals pp. 582–602. Harvard University Press: Cambridge (Massachusetts).

[B93] Benton, M. J. 1993. Reptilia. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 681–715. Chapman & Hall: London.

[C77] Cope, E. D. 1877. Report upon the extinct Vertebrata obtained in New Mexico by parties of the expedition of 1874. Geographical Surveys West of the One Hundredth Meridian 4 (2): i–iv, 1–370.

[D07] Dixon, D. 2007. The Complete Illustrated Encyclopedia of Dinosaurs & Prehistoric Creatures. Hermes House: London.

[GM88] Gaffney, E. S., & P. A. Meylan. 1988. A phylogeny of turtles. In: Benton, M. J. (ed.) The Phylogeny and Classification of the Tetrapods vol. 1. Amphibians, Reptiles, Birds pp. 157–219. Clarendon Press: Oxford.

[JPG04] Joyce, W. G., J. F. Parham & J. A. Gauthier. 2004. Developing a protocol for the conversion of rank-based taxon names to phylogenetically defined clade names, as exemplified by turtles. Journal of Paleontology 78 (5): 989–1013.

[LW08] Li, C., X.-C. Wu, O. Rieppel, L.-T. Wang & L.-J. Zhao. 2008. An ancestral turtle from the Late Triassic of southwestern China. Nature 456: 497–501.

[PST99] Pereda Suberbiola, X., & P. Taquet. 1999. Restes de Rhabdodon (dinosaure ornithopode) de Transylvanie donnés par Nopcsa au Muséum national d’Histoire naturelle de Paris. Geodiversitas 21 (2): 157–166.

[RB05] Rage, J.-C., & S. Bailon. 2005. Amphibians and squamate reptiles from the late early Miocene (MN 4) of Béon 1 (Montréal-du-Gers, southwestern France). Geodiversitas 27 (3): 413–441.

[R93] Rieppel, O. 1993. Patterns of diversity in the reptilian skull. In: Hanken, J., & B. K. Hall (eds) 1993. The Skull vol. 2. Patterns of Structural and Systematic Diversity pp. 344–390. The University of Chicago Press.

[W06] Werner, F. 1906. Die nördlichsten Reptilien und Batrachier. In: Römer, F., & F. Schaudinn (eds) Fauna Arctica. Eine Zusammenstellun der arktischen Tierformen, mit besonder Berücksichtigung des Spitzbergen-Gebietes auf Grund der Ergebnisse der Deutschen Expedition in das Nördliche Eismeer im Jahre 1898 vol. 4 pp. 527–544. Gustav Fischer: Jena.

[ZBH03] Zhou, Z., P. M. Barrett & J. Hilton. 2003. An exceptionally preserved Lower Cretaceous ecosystem. Nature 421: 807–814.