Living on an island: Characterization of the encrusting fauna of large pectinid bivalves from the Lower Cretaceous of the Neuquén Basin, west-central Argentina

Exposed mollusc shells may act as benthic islands in soft bottoms, and the analysis of their encrusting faunas provides unique palaeoecological information. In the late Valanginian of the Agrio Formation (Neuquén Basin, west-central Argentina), the large pectinid Prohinnites acted as a benthic islan...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Luci, Leticia, Lazo, Dario Gustavo
Publicado: 2015
Materias:
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00241164_v48_n2_p205_Luci
http://hdl.handle.net/20.500.12110/paper_00241164_v48_n2_p205_Luci
Aporte de:
id paper:paper_00241164_v48_n2_p205_Luci
record_format dspace
spelling paper:paper_00241164_v48_n2_p205_Luci2023-06-08T14:51:56Z Living on an island: Characterization of the encrusting fauna of large pectinid bivalves from the Lower Cretaceous of the Neuquén Basin, west-central Argentina Luci, Leticia Lazo, Dario Gustavo Benthic island Encrustation Gregariousness Hard substrate fauna Prohinnites abundance bivalve Cretaceous fauna island larva paleoecology taxonomy Argentina Neuquen Basin Bivalvia Mollusca Pectinidae Exposed mollusc shells may act as benthic islands in soft bottoms, and the analysis of their encrusting faunas provides unique palaeoecological information. In the late Valanginian of the Agrio Formation (Neuquén Basin, west-central Argentina), the large pectinid Prohinnites acted as a benthic island on soft substrates. Inequivalved Prohinnites adults with small, smooth cementing scars on the right valve suggest that a free reclining life habit followed the epibyssate juvenile and cementing phases. The encrusting fauna on Prohinnites was studied taxonomically and palaeoecologically by means of a quantitative approach. Over 90% of 123 valves presented encrusters. Encrustation was equally common in both valves. Internal encrustation was rare. The left umbonal region was less encrusted probably due to sediment accumulation or early colonization by soft-bodied taxa. The fauna was composed of 14 encrusting taxa, including oysters, serpulids, sabellids and cyclostome bryozoans. Oysters exceeded 50% of the total abundance, but serpulids and bryozoans were more diverse. Serpulids and particularly oysters showed a gregarious life habit. Few interactions took place among encrusters and most were post-mortem, involving the overgrowth of already dead oysters. The oysters were early settlers that took advantage of their gregarious behaviour to rapidly cover available hard surfaces. However, they were unable to exclude bryozoans and polychaetes, which settled on the pectinid's valves regardless of the presence of oysters. The studied fauna corresponds to a climax community that was structured by larval abundance rather than by competitive interactions; oysters settled first and replenished themselves while polychaetes and bryozoans settled over or alongside them. © 2014 Lethaia Foundation. Fil:Luci, L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Lazo, D.G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2015 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00241164_v48_n2_p205_Luci http://hdl.handle.net/20.500.12110/paper_00241164_v48_n2_p205_Luci
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Benthic island
Encrustation
Gregariousness
Hard substrate fauna
Prohinnites
abundance
bivalve
Cretaceous
fauna
island
larva
paleoecology
taxonomy
Argentina
Neuquen Basin
Bivalvia
Mollusca
Pectinidae
spellingShingle Benthic island
Encrustation
Gregariousness
Hard substrate fauna
Prohinnites
abundance
bivalve
Cretaceous
fauna
island
larva
paleoecology
taxonomy
Argentina
Neuquen Basin
Bivalvia
Mollusca
Pectinidae
Luci, Leticia
Lazo, Dario Gustavo
Living on an island: Characterization of the encrusting fauna of large pectinid bivalves from the Lower Cretaceous of the Neuquén Basin, west-central Argentina
topic_facet Benthic island
Encrustation
Gregariousness
Hard substrate fauna
Prohinnites
abundance
bivalve
Cretaceous
fauna
island
larva
paleoecology
taxonomy
Argentina
Neuquen Basin
Bivalvia
Mollusca
Pectinidae
description Exposed mollusc shells may act as benthic islands in soft bottoms, and the analysis of their encrusting faunas provides unique palaeoecological information. In the late Valanginian of the Agrio Formation (Neuquén Basin, west-central Argentina), the large pectinid Prohinnites acted as a benthic island on soft substrates. Inequivalved Prohinnites adults with small, smooth cementing scars on the right valve suggest that a free reclining life habit followed the epibyssate juvenile and cementing phases. The encrusting fauna on Prohinnites was studied taxonomically and palaeoecologically by means of a quantitative approach. Over 90% of 123 valves presented encrusters. Encrustation was equally common in both valves. Internal encrustation was rare. The left umbonal region was less encrusted probably due to sediment accumulation or early colonization by soft-bodied taxa. The fauna was composed of 14 encrusting taxa, including oysters, serpulids, sabellids and cyclostome bryozoans. Oysters exceeded 50% of the total abundance, but serpulids and bryozoans were more diverse. Serpulids and particularly oysters showed a gregarious life habit. Few interactions took place among encrusters and most were post-mortem, involving the overgrowth of already dead oysters. The oysters were early settlers that took advantage of their gregarious behaviour to rapidly cover available hard surfaces. However, they were unable to exclude bryozoans and polychaetes, which settled on the pectinid's valves regardless of the presence of oysters. The studied fauna corresponds to a climax community that was structured by larval abundance rather than by competitive interactions; oysters settled first and replenished themselves while polychaetes and bryozoans settled over or alongside them. © 2014 Lethaia Foundation.
author Luci, Leticia
Lazo, Dario Gustavo
author_facet Luci, Leticia
Lazo, Dario Gustavo
author_sort Luci, Leticia
title Living on an island: Characterization of the encrusting fauna of large pectinid bivalves from the Lower Cretaceous of the Neuquén Basin, west-central Argentina
title_short Living on an island: Characterization of the encrusting fauna of large pectinid bivalves from the Lower Cretaceous of the Neuquén Basin, west-central Argentina
title_full Living on an island: Characterization of the encrusting fauna of large pectinid bivalves from the Lower Cretaceous of the Neuquén Basin, west-central Argentina
title_fullStr Living on an island: Characterization of the encrusting fauna of large pectinid bivalves from the Lower Cretaceous of the Neuquén Basin, west-central Argentina
title_full_unstemmed Living on an island: Characterization of the encrusting fauna of large pectinid bivalves from the Lower Cretaceous of the Neuquén Basin, west-central Argentina
title_sort living on an island: characterization of the encrusting fauna of large pectinid bivalves from the lower cretaceous of the neuquén basin, west-central argentina
publishDate 2015
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00241164_v48_n2_p205_Luci
http://hdl.handle.net/20.500.12110/paper_00241164_v48_n2_p205_Luci
work_keys_str_mv AT lucileticia livingonanislandcharacterizationoftheencrustingfaunaoflargepectinidbivalvesfromthelowercretaceousoftheneuquenbasinwestcentralargentina
AT lazodariogustavo livingonanislandcharacterizationoftheencrustingfaunaoflargepectinidbivalvesfromthelowercretaceousoftheneuquenbasinwestcentralargentina
_version_ 1768545497307414528