|mhorn||Дата: Friday, 07.02.2014, 17:51 | Сообщение # 1|
|Fernandez-Lopez S.R., Chong Diaz G.B. (2011) Dimorphinites (Ammonoidea, Jurassic, upper Bajocian) in the Precordillera of northern Chile // Journal of Paleontology, 85(3), p. 395–405. |
A new upper Bajocian ammonite assemblage containing the morphoceratids Dimorphinites dimorphus (d'Orbigny) and Vigoriceras defrancei (d'Orbigny) is reported from the circum-Pacific area. These ammonites were found at the top of the Torcazas Formation, in the Quebrada San Pedro area, Precordillera of northern Chile. Taphonomic, systematic, and paleobiogeographic data confirm these dimorphs were part of indigenous populations within the Tarapaca Basin, belonging to the same demic biospecies: Dimorphinites defrancei (d'Orbigny). The West Tethyan and East-Pacific distribution of D. defrancei corroborates the availability of the migratory seaway, the so-called Hispanic Corridor, between the western Tethys and the eastern Pacific Ocean during the upper Bajocian Parkinsoni Zone.
Middle Jurassic - Lower Cretaceous ammonites & aptychi