Sauropterygia from the Middle Triassic of Makhtesh Ramon, Negev, Israel
By: Olivier Rieppel --, Jean-Michel Mazin --, Eitan Tchernov --.
Contributors: Mazin, Jean-Michel.; Tchernov, E.
Series: Fieldiana -- new ser., no. 40; Publication -- 1499; Publication (Field Museum of Natural History) -- 1499.
Publisher: Field Museum of Natural History
Published: 1999
Place of publication: Chicago, Ill
Subjects: Sauropterygia -- Israel -- Ramon Crater.; Paleontology -- Triassic.
Other titles: Sauropterygia from Makhtesh Ramon; Fieldiana: Geology, new series, no. 40
Description: The Sauropterygia of the Middle Triassic Muschelkalk of Makhtesh Ramon, Negev, are reviewed, and their evolutionary and paleobiogeographic history is reconstructed on the basis of cladistic analysis of their interrelationships. The fauna includes cyamodontoid placodonts (?Psephosaurus) as well as Eosauropterygia such as possible pachypleurosaurs, Simosaurus sp., at least three diagnosable taxa of Nothosaurus (Nothosaurus cf. N. giganteus, N. haasi n. sp., and N. tchernovi), and one lariosaur (Lariosaurus stensioei). -- The use of cyamodontoids for historical biogeographic analysis remains impeded because the diagnosis of lower Muschelkalk taxa (?Psephosaurus, Cyamodus) remains incomplete. The taxic composition of the eosauropterygian fauna, as well as the pattern of cladistic relationships of its nothosaurian components, indicates paleobiogeographic affinities of the Makhtesh Ramon fauna with the Germanic and Alpine realm, supporting the hypothesis of a Burgundian Gage that connected the Germanic basin with the southern branch of the developing Neotethys during upper Anisian and Ladinian times. -- Refined analysis of Nothosaurus documents the occurrence of the sister species N. haasi n. sp. and N. tchernovi at Makhtesh Ramon, which provides evidence for dichotomous speciation and habitat partitioning within the intraplatform basin habitat characteristic of the northern Gondwanan shelf (southern margin of the developing southern branch of the Neotethys) during Anisian and Ladinian times.