Ontogeny and autecology of an Early Cretaceous trigoniide bivalve from Neuquén Basin, Argentina

Understanding ontogenetic variation is fundamental for adequate species definition and is the key for recognizing evolutionary relevant processes like heterochrony or developmental constraints. The larval and post-larval shell ontogeny and the ecology of the trigoniide bivalve Myophorella garatei ar...

Descripción completa

Detalles Bibliográficos
Autor principal: Echevarría, Javier
Formato: Articulo
Lenguaje:Inglés
Publicado: 2014
Materias:
Ciencias Naturales
allometry
Argentina
Bivalvia
Cretaceous
larval development
life habits
Mollusca
ontogeny
shell growth
Trigoniida
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/85515
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-85515
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Naturales
allometry
Argentina
Bivalvia
Cretaceous
larval development
life habits
Mollusca
ontogeny
shell growth
Trigoniida
spellingShingle Ciencias Naturales
allometry
Argentina
Bivalvia
Cretaceous
larval development
life habits
Mollusca
ontogeny
shell growth
Trigoniida
Echevarría, Javier
Ontogeny and autecology of an Early Cretaceous trigoniide bivalve from Neuquén Basin, Argentina
topic_facet Ciencias Naturales
allometry
Argentina
Bivalvia
Cretaceous
larval development
life habits
Mollusca
ontogeny
shell growth
Trigoniida
description Understanding ontogenetic variation is fundamental for adequate species definition and is the key for recognizing evolutionary relevant processes like heterochrony or developmental constraints. The larval and post-larval shell ontogeny and the ecology of the trigoniide bivalve Myophorella garatei are described in this paper. The species occurs in offshore transition facies of the late Valanginian Pilmatué Member of the Agrio Formation in the Neuquén Basin, Argentina. The larval shell has a rather small prodissoconch I; and if prodissoconch II is present, it is rather weakly developed. From these data, a larval stage of low dispersal capability is inferred for Myophorella garatei, either short-lived planktotrophic or nonplanktotrophic. The study of post-larval development included general shell shape and ornamentation. To assess general shell shape a geometric morphometric analysis was performed on the lateral view, together with a study of allometry for the shell width. As a result, two main allometric stages of development could be identified. During the first stage a relative size reduction of the area co-occurs with a slight elongation of the shell, while the second stage is marked by dorsal bending of the shell and an increase on relative width. Ornamentation was examined qualitatively, but also a geometric morphometric analysis was performed on the flank costae. The first two flank costae are subconcentric; from the third costa onwards they become oblique, intially changing from more curved to less curved shapes, while on a third stage they show the opposite trend. Finally, a general interpretation of the adaptive morphology of adult shell was performed, concluding that M. garatei was adapted to low energy, soft bottom environments, and probably lived with the posterior straight margin levelled at the water-sediment interface.
format Articulo
Articulo
author Echevarría, Javier
author_facet Echevarría, Javier
author_sort Echevarría, Javier
title Ontogeny and autecology of an Early Cretaceous trigoniide bivalve from Neuquén Basin, Argentina
title_short Ontogeny and autecology of an Early Cretaceous trigoniide bivalve from Neuquén Basin, Argentina
title_full Ontogeny and autecology of an Early Cretaceous trigoniide bivalve from Neuquén Basin, Argentina
title_fullStr Ontogeny and autecology of an Early Cretaceous trigoniide bivalve from Neuquén Basin, Argentina
title_full_unstemmed Ontogeny and autecology of an Early Cretaceous trigoniide bivalve from Neuquén Basin, Argentina
title_sort ontogeny and autecology of an early cretaceous trigoniide bivalve from neuquén basin, argentina
publishDate 2014
url http://sedici.unlp.edu.ar/handle/10915/85515
work_keys_str_mv AT echevarriajavier ontogenyandautecologyofanearlycretaceoustrigoniidebivalvefromneuquenbasinargentina
bdutipo_str Repositorios
_version_ 1764820489471000576

Ejemplares similares