Revision of Valanginian Steinmanellinae bivalves from the Neuquén basin,West-central Argentina,and their biostratigraphic implications |
| |
Institution: | 1. Key Laboratory of Western China''s Mineral Resources of Gansu Province, School of Earth Sciences, Lanzhou University, Lanzhou, 730000, China;2. Department of Earth Sciences, University of Oregon, Eugene, Oregon 97403, USA;3. Research Centre of Global Change, School of Geographical Science, Fujian Normal University, Fuzhou 350007, China;1. Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Cittadella Universitaria (Blocco A) - SS.554 bivio per Sestu, 09042 Monserrato, CA, Italy;2. IRSPS, Università d''Annunzio, viale Pindaro 42, I-65127 Pescara, Italy;3. Geological-Paleontological Department, Natural History Museum Vienna, Burgring 7, A-1010 Vienna, Austria |
| |
Abstract: | We present a new species of Steinmanella Crickmay from the Valanginian of the Neuquén Basin, west-central Argentina, and at the same time update a Valanginian–earliest Barremian bivalve zonation which is integrated into the local, Chilean and European standard ammonoid zonations. Steinmanella caicayensis sp. nov. presents a moderately inflated shell, a subtriangular outline, well-developed carinae and a straight to moderately convex anterior margin. Steinmanella is very abundant in the Tithonian–Barremian interval in the basin and thus provides an ideal opportunity to perform detailed taxonomic and stratigraphic studies; a former zonation based on these trigonioids is here revised and expanded with a thorough revision of Valanginian occurrences based on new material. Two new zones are proposed, namely the S. quintucoensis and S. caicayensis zones, encompassing Valanginian times. The proposed bivalve zonation encompassing the Valanginian–earliest Barremian time interval can be useful in correlating with other southwestern Gondwanan regions, such as Perú, Chile, South Africa, Tanzania, and India, where Steinmanella has been recorded. |
| |
Keywords: | Agrio Formation Valanginian Biostratigraphy Trigonioida |
本文献已被 ScienceDirect 等数据库收录! |
|