%0 Book Section
%T Aalenian Tmetoceras (Ammonoidea) from Iberia: taxonomy, habitats and evolution.
publisher Kluwer
%D 1999
%U 978-1-4613-7193-9
%@ https://hdl.handle.net/20.500.14352/60716
%X Several hundred Aalenian Tmetoceras from the Iberian Peninsula (N Lusitanian Basin, Asturias,Basque-Cantabrian Basin, NE Cameros, NW Iberian Basin, Aragonese Platform,Tortosa Platform, Castilian Platform, Majorca and Betic Basin) have been reviewed. Twospecies of Aalenian Tmetoceras have been identified on the basis of morphological, biochronologicaland palaeobiogeographical data: T. scissum and T. regleyi.T. scissum was dominant among the Tmetoceras populations developed in the Beticand Lusitanian basins during Opalinum, Murchisonae and Bradfordensis biochrons. Populationscomposed by evolute individuals of T. scissum inhabited shelfal or oceanic environments.A chronocline, from rectiradiate and primitive forms to flexicostate and derivedforms, can be recognized in these populations of T. scissum. In contrast, shallow epicontinentalplatforms were inhabited by involute individuals of T. regleyi. This second specieswas phyletically derived from T. scissum, representing an adaptive radiation from populationsof shelfal or oceanic basins to populations of epicontinental platforms.
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