Autecology of Wolfestheria smekali (Spinicaudata) from the Upper Jurassic (Cañadón Asfalto Formation), Patagonia, Argentina

Spinicaudatans are small branchiopod crustaceans also usually known as 'Conchostraca'. They are easily recognizable by their short, laterally-compressed body inside of a characteristic bivalved, lightly-mineralized chitin carapace which is often the only preserved element of the group in t...

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Autores principales: Monferran, M.D., Gallego, O.F., Astrop, T.I., Cabaleri, N.
Formato: JOUR
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00310182_v392_n_p52_Monferran
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spelling todo:paper_00310182_v392_n_p52_Monferran2023-10-03T14:40:56Z Autecology of Wolfestheria smekali (Spinicaudata) from the Upper Jurassic (Cañadón Asfalto Formation), Patagonia, Argentina Monferran, M.D. Gallego, O.F. Astrop, T.I. Cabaleri, N. Arthropoda Branchiopoda Crustacea Diplostraca South America autecology bivalve caddisfly chitin dioecy ephemeral pool fossil record Jurassic morphology morphometry ostracod paleoecology paleoenvironment population density reproductive strategy sex ratio sexual dimorphism Argentina Chubut Chubut River Patagonia Spinicaudatans are small branchiopod crustaceans also usually known as 'Conchostraca'. They are easily recognizable by their short, laterally-compressed body inside of a characteristic bivalved, lightly-mineralized chitin carapace which is often the only preserved element of the group in the fossil record. The valves of the carapace are distinctive due to the presence of growth lines which are produced by the accumulation of successive cuticle layers retained after ecdysis. 'Conchostracan' paleoecology has been the subject of several previous studies-most focus on the paleoenvironment of the rock units in which the fossils were found. Few studies have been carried out on the paleoautecology of fossil taxa. In this work, an exploratory study was performed regarding the paleoautecology of the small clam shrimp Wolfestheria smekali Gallego and Monferran 2013, from the Cañadón Asfalto Formation (Upper Jurassic) in the Argentinean Chubut province in Patagonia, with the objective of understanding the ecological characteristics of individuals and populations within this species. Samples were collected from four stratigraphic levels in the Estancia La Sin Rumbo locality (in the Chubut River middle valley). W. smekali was found in association with the darwinuloid ostracod Penthesilenula sarytirmenensis Sharapova, mollusks assigned to the genus Diplodon Spix, and insects represented by larval cases from the order Trichoptera (caddisflies, Ostracindusia and Conchindusia). The population density of W. smekali in each sample was recorded and morphometric analyses were performed on a selected subsample of individuals. This technique allowed the discrimination of sexual dimorphism where males have a telliniform, ovate-elliptical shape, and females have a cycladiform, subcircular-subtriangular shape. Given the sex-ratio observed in the samples collected, it is likely that the species had a dioecious reproductive system (50% males, 50% females). It is hoped that the present work will give new insights into the dynamics of ancient ephemeral pools and serve as a foundation for future studies of fossil Spinicaudata. © 2013 Elsevier B.V. Fil:Cabaleri, N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00310182_v392_n_p52_Monferran
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Arthropoda
Branchiopoda
Crustacea
Diplostraca
South America
autecology
bivalve
caddisfly
chitin
dioecy
ephemeral pool
fossil record
Jurassic
morphology
morphometry
ostracod
paleoecology
paleoenvironment
population density
reproductive strategy
sex ratio
sexual dimorphism
Argentina
Chubut
Chubut River
Patagonia
spellingShingle Arthropoda
Branchiopoda
Crustacea
Diplostraca
South America
autecology
bivalve
caddisfly
chitin
dioecy
ephemeral pool
fossil record
Jurassic
morphology
morphometry
ostracod
paleoecology
paleoenvironment
population density
reproductive strategy
sex ratio
sexual dimorphism
Argentina
Chubut
Chubut River
Patagonia
Monferran, M.D.
Gallego, O.F.
Astrop, T.I.
Cabaleri, N.
Autecology of Wolfestheria smekali (Spinicaudata) from the Upper Jurassic (Cañadón Asfalto Formation), Patagonia, Argentina
topic_facet Arthropoda
Branchiopoda
Crustacea
Diplostraca
South America
autecology
bivalve
caddisfly
chitin
dioecy
ephemeral pool
fossil record
Jurassic
morphology
morphometry
ostracod
paleoecology
paleoenvironment
population density
reproductive strategy
sex ratio
sexual dimorphism
Argentina
Chubut
Chubut River
Patagonia
description Spinicaudatans are small branchiopod crustaceans also usually known as 'Conchostraca'. They are easily recognizable by their short, laterally-compressed body inside of a characteristic bivalved, lightly-mineralized chitin carapace which is often the only preserved element of the group in the fossil record. The valves of the carapace are distinctive due to the presence of growth lines which are produced by the accumulation of successive cuticle layers retained after ecdysis. 'Conchostracan' paleoecology has been the subject of several previous studies-most focus on the paleoenvironment of the rock units in which the fossils were found. Few studies have been carried out on the paleoautecology of fossil taxa. In this work, an exploratory study was performed regarding the paleoautecology of the small clam shrimp Wolfestheria smekali Gallego and Monferran 2013, from the Cañadón Asfalto Formation (Upper Jurassic) in the Argentinean Chubut province in Patagonia, with the objective of understanding the ecological characteristics of individuals and populations within this species. Samples were collected from four stratigraphic levels in the Estancia La Sin Rumbo locality (in the Chubut River middle valley). W. smekali was found in association with the darwinuloid ostracod Penthesilenula sarytirmenensis Sharapova, mollusks assigned to the genus Diplodon Spix, and insects represented by larval cases from the order Trichoptera (caddisflies, Ostracindusia and Conchindusia). The population density of W. smekali in each sample was recorded and morphometric analyses were performed on a selected subsample of individuals. This technique allowed the discrimination of sexual dimorphism where males have a telliniform, ovate-elliptical shape, and females have a cycladiform, subcircular-subtriangular shape. Given the sex-ratio observed in the samples collected, it is likely that the species had a dioecious reproductive system (50% males, 50% females). It is hoped that the present work will give new insights into the dynamics of ancient ephemeral pools and serve as a foundation for future studies of fossil Spinicaudata. © 2013 Elsevier B.V.
format JOUR
author Monferran, M.D.
Gallego, O.F.
Astrop, T.I.
Cabaleri, N.
author_facet Monferran, M.D.
Gallego, O.F.
Astrop, T.I.
Cabaleri, N.
author_sort Monferran, M.D.
title Autecology of Wolfestheria smekali (Spinicaudata) from the Upper Jurassic (Cañadón Asfalto Formation), Patagonia, Argentina
title_short Autecology of Wolfestheria smekali (Spinicaudata) from the Upper Jurassic (Cañadón Asfalto Formation), Patagonia, Argentina
title_full Autecology of Wolfestheria smekali (Spinicaudata) from the Upper Jurassic (Cañadón Asfalto Formation), Patagonia, Argentina
title_fullStr Autecology of Wolfestheria smekali (Spinicaudata) from the Upper Jurassic (Cañadón Asfalto Formation), Patagonia, Argentina
title_full_unstemmed Autecology of Wolfestheria smekali (Spinicaudata) from the Upper Jurassic (Cañadón Asfalto Formation), Patagonia, Argentina
title_sort autecology of wolfestheria smekali (spinicaudata) from the upper jurassic (cañadón asfalto formation), patagonia, argentina
url http://hdl.handle.net/20.500.12110/paper_00310182_v392_n_p52_Monferran
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