Extinction selectivity and diversity depletion in the Triassic/Jurassic boundary among bivalves

Diversity depletion is the result of the combined action of origination and extinction rates. The present study is an attempt to understand this dynamic by the analysis of the end-Triassic extinction event in a very well represented group: the marine bivalves. This is tackled in two steps: a) first...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Ros, Sonia, Echevarría, Javier
Formato: Objeto de conferencia
Lenguaje:Inglés
Publicado: 2010
Materias:
Ciencias Naturales
Paleontología
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/16961
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-16961
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
Paleontología
spellingShingle Ciencias Naturales
Paleontología
Ros, Sonia
Echevarría, Javier
Extinction selectivity and diversity depletion in the Triassic/Jurassic boundary among bivalves
topic_facet Ciencias Naturales
Paleontología
description Diversity depletion is the result of the combined action of origination and extinction rates. The present study is an attempt to understand this dynamic by the analysis of the end-Triassic extinction event in a very well represented group: the marine bivalves. This is tackled in two steps: a) first we test the selectivity of extinction respect to the main autoecological characteristics of the genera (feeding mechanism, tiering, motility and attachment) among other features (mineralogy, age at the T-J boundary, paleogeographic distribution) by means of generalized linear models and resampling methods; and b) we analyze the evolutionary rates in the orders included. The results of the selectivity analysis show: 1) a positive selection for deep burrowers and a negative selection against reclined habits; 2) a significant association between mineralogy and survival odds, although this could be due to the strong correlation between mineralogy and tiering; 3) a lack of selection for age or geographic distribution (both traits strongly associated), although the last one would require a more detailed examination. From the analysis of the evolutionary rates we can conclude that: 1- all the orders show a negative growth rate during the Rhaetian (in some of them already starting during the Norian), with the main exception of generalist orders (Arcoida, Mytiloida) and deep burrowers (Pholadomyoida); 2- the most affected orders were Hippuritoida (reclined), Trigonioida, Nuculoida (both shallow burrowers) and Modiomorphoida (mostly shallow burrowers and endobyssate). The lack of selectivity for age and distribution points to an indiscriminate extinction. On the other hand, the preferential survival of deep burrowers suggests that some isolated environments were not equally affected by the general disruption; and the differences in growth rates show that the extinction event was strong enough to affect the specialized guilds, but not enough to affect the generalist ones.
format Objeto de conferencia
Objeto de conferencia
author Ros, Sonia
Echevarría, Javier
author_facet Ros, Sonia
Echevarría, Javier
author_sort Ros, Sonia
title Extinction selectivity and diversity depletion in the Triassic/Jurassic boundary among bivalves
title_short Extinction selectivity and diversity depletion in the Triassic/Jurassic boundary among bivalves
title_full Extinction selectivity and diversity depletion in the Triassic/Jurassic boundary among bivalves
title_fullStr Extinction selectivity and diversity depletion in the Triassic/Jurassic boundary among bivalves
title_full_unstemmed Extinction selectivity and diversity depletion in the Triassic/Jurassic boundary among bivalves
title_sort extinction selectivity and diversity depletion in the triassic/jurassic boundary among bivalves
publishDate 2010
url http://sedici.unlp.edu.ar/handle/10915/16961
work_keys_str_mv AT rossonia extinctionselectivityanddiversitydepletioninthetriassicjurassicboundaryamongbivalves
AT echevarriajavier extinctionselectivityanddiversitydepletioninthetriassicjurassicboundaryamongbivalves
bdutipo_str Repositorios
_version_ 1764820464781230082

Ejemplares similares