Evolution of the last koninckinids (Athyridida, Koninckinidae), a precursor signal of the early Toarcian mass extinction event in the Western Tethys


Autoria(s): Baeza Carratalá, José Francisco; García Joral, Fernando; Giannetti, Alice; Tent-Manclus, Jose Enrique
Contribuinte(s)

Universidad de Alicante. Departamento de Ciencias de la Tierra y del Medio Ambiente

Cambios Paleoambientales

Evolución Geodinámica de la Cordillera Bética Oriental y de la Plataforma Marina de Alicante

Data(s)

06/05/2015

06/05/2015

01/07/2015

Resumo

Koninckinids are a suitable group to shed light on the biotic crisis suffered by brachiopod fauna in the Early Jurassic. Koninckinid fauna recorded in the late Pliensbachian–early Toarcian from the easternmost Subbetic basin is analyzed and identified as a precursor signal for one of the most conspicuous mass extinction events of the Phylum Brachiopoda, a multi-phased interval with episodes of changing environmental conditions, whose onset can be detected from the Elisa–Mirabile subzones up to the early Toarcian extinction boundary in the lowermost Serpentinum Zone (T-OAE). The koninckinid fauna had a previously well-established migration pattern from the intra-Tethyan to the NW-European basins but a first phase with a progressive warming episode in the Pliensbachian–Toarcian transition triggered a koninckinid fauna exodus from the eastern/central Tethys toward the westernmost Mediterranean margins. A second stage shows an adaptive response to more adverse conditions in the westernmost Tethyan margins and finally, an escape and extinction phase is detected in the Atlantic areas from the mid-Polymorphum Zone onwards up to their global extinction in the lowermost Serpentinum Zone. This migration pattern is independent of the paleogeographic bioprovinciality and is unrelated to a facies-controlled pattern. The anoxic/suboxic environmental conditions should only be considered as a minor factor of partial control since well-oxygenated habitats are noted in the intra-Tethyan basins and this factor is noticeable only in the second westward migratory stage (with dwarf taxa and oligotypical assemblages). The analysis of cold-seep proxies in the Subbetic deposits suggests a radiation that is independent of methane releases in the Subbetic basin.

This research is a contribution to the projects CGL2011-25894 and CGL2011-23947 (Ministry of Science and Innovation, Government of Spain) and to the Research Group VIGROB-167 (University of Alicante).

Identificador

Palaeogeography, Palaeoclimatology, Palaeoecology. 2015, 429: 41-56. doi:10.1016/j.palaeo.2015.04.004

0031-0182 (Print)

1872-616X (Online)

http://hdl.handle.net/10045/46645

10.1016/j.palaeo.2015.04.004

Idioma(s)

eng

Publicador

Elsevier

Relação

http://dx.doi.org/10.1016/j.palaeo.2015.04.004

Direitos

© 2015 Elsevier B.V.

info:eu-repo/semantics/openAccess

Palavras-Chave #Early Jurassic #Mass extinction #Koninckinids #Western Tethys #Paleontología #Geodinámica Interna
Tipo

info:eu-repo/semantics/article