Morphology and environment in the Jurassic Nucleatidae (Brachiopoda) from Western Tethys

Nucleatidae (Brachiopoda, Terebratulida) are commonly considered as typical members of the Mediterranean assemblages during the Jurassic. However, nucleatids occasionally also occur in the margins of Western Tethys (Northwestern European shelf). Some of these occurrences in northeastern Spain are an...

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Detalles Bibliográficos
Autores: Colás, Jorge, García Joral, Fernando
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/42980
Acceso en línea:https://hdl.handle.net/20.500.14352/42980
Access Level:acceso abierto
Palabra clave:564.8 (460)
551.762 (460)
Brachiopods
Nucleatidae
Functional morphology
adaptation
Systematics
Jurassic
Spain.
Paleontología
2416 Paleontología
Descripción
Sumario:Nucleatidae (Brachiopoda, Terebratulida) are commonly considered as typical members of the Mediterranean assemblages during the Jurassic. However, nucleatids occasionally also occur in the margins of Western Tethys (Northwestern European shelf). Some of these occurrences in northeastern Spain are analysed, detecting a relation between nucleatid morphology and palaeoenvironment during the Jurassic. The validity of this relationship for the whole of the representatives of the group in the Western Tethys during the Jurassic is tested by means of morphofunctional analyses (principal components analysis and discriminant analysis), concluding that reduction of the lateral expansion of the shell is the key morphological feature whereby epioceanic and epicontinental taxa differ. This change can have functional significance because it can be interpreted as a mechanism to reduce the area exposed when the valves gape, increasing protection against harmful particles in environments characterized by higher terrigenous input. Some modifications on the systematics of the Nucleatidae at the genus level are proposed on the basis of the temporal and biogeographical distribution of these adaptations.