RT Book, Section
T1 Aalenian Tmetoceras (Ammonoidea) from Iberia: taphonomy and palaeobiogeography
A1 Fernández López, Sixto Rafael
A1 Henriques, María Helena Paiva
A1 Linares Rodríguez, Asunción
A2 Oloriz Saez, Federico
A2 Rodríguez Tovar, Francisco Javier
AB From different areas of the Iberian Peninsula more than 600 specimens of Aalenian Tmetocerashave been found. This taxonomic group represents less than 20% of the whole ammonoidsrecorded in Opalinum, Murchisonae, Bradfordensis and Concavum biozones.Tmetoceras representatives, as well as Phylloceratina and Lytoceratina, were more frequentin shelfal basins than in epicontinental platforms. Taphonomic data suggest aeudemic character of the representatives of T. scissum in shelfal basins or oceanic areas.Exceptional immigrants and drifted shells of this species arrived in shallow environmentsof neighbouring platforms. In contrast, representatives of T. regleyi inhabited preferentiallyshallow environments of epicontinental platforms.T. scissum was a pandemic species, inhabiting oceanic or shelfal environments in theearly Aalenian. However, some species of Tmetoceras, such as T. regleyi and T. flexicostatum,were geographically restricted in very distant areas. T. regleyi has been found only in European areas of the West Tethyan Subrealm. A pattern of adaptive radiation may have takenplace in the Western Tethys during the Opalinum-Murchisonae biochrons, giving rise to T.regleyi from T. scissum. Specialized forms of Tmetoceras (k-strategists such as the individualsof the species T. regleyi) are widespread in the epicontinental platforms around the WesternTethys during the Murchisonae and Bradfordensis biochrons. Epicontinental, specializedforms of T. regleyi suffered extinction in the latest Bradfordensis Biochron. Shelfal or oceanic,generalist forms of T. scissum disappeared in the Western Tethys or the MediterraneanProvince in the latest Bradfordensis Biochron, but they survived in the East-Pacific Subrealm.
PB Kluwer
SN 978-1-4613-7193-9
YR 1996
FD 1996
LK https://hdl.handle.net/20.500.14352/60718
UL https://hdl.handle.net/20.500.14352/60718
LA eng
DS Docta Complutense
RD 19 ene 2026