Nereites in Lower Cretaceous marginal-marine facies from Patagonia: Ichnotaxonomic and ethological implications

Detailed descriptions of Nereites are uncommon. In this work, Nereites are thoroughly described from tidally influenced and wave dominated deposits in the Cretaceous of the Neuquén Basin (northern Patagonia). These Nereites show a great morphological variety in bedding-plane view. The application of...

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Publicado: 2018
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01956671_v81_n_p51_Fernandez
http://hdl.handle.net/20.500.12110/paper_01956671_v81_n_p51_Fernandez
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spelling paper:paper_01956671_v81_n_p51_Fernandez2023-06-08T15:20:22Z Nereites in Lower Cretaceous marginal-marine facies from Patagonia: Ichnotaxonomic and ethological implications Cretaceous Ethology Marginal marine Nereites South America Tracemaker Cretaceous facies analysis ichnology marginal sea morphology paleoenvironment taxonomy trace fossil Patagonia Nereites Detailed descriptions of Nereites are uncommon. In this work, Nereites are thoroughly described from tidally influenced and wave dominated deposits in the Cretaceous of the Neuquén Basin (northern Patagonia). These Nereites show a great morphological variety in bedding-plane view. The application of different possible tracemakers for this renowned ichnogenus is discussed. Besides the well known morphology consisting of median tunnel surrounded by a halo composed of reworked material, a tripartite burrow structure has been observed that comprises in addition a disturbed, but not reworked zone at the external side of the reworking halo. The studied material provides evidence that the producers of these Nereites were shallow infaunal deposit-feeding organisms, a feeding strategy mentioned in many studies of the ichnogenus as matching a worm-like tracemaker, while the subsurface characteristics, particularly the disturbed outer zone, support a burrowing arthropod as tracemaker. Consequently, for interpretation of the potential trace producer, basic feeding strategy and burrow construction method should be differentiated and neither should be automatically linked with one particular tracemaker. The different morphologies of these Nereites allow referral of part of this material to N. missouriensis, but some cases of transitional forms remain problematic. The ratio between the width of the median tunnel and the enveloping zone (used as an ichnotaxobase) is not always due to variation in the burrowing depth of the producer. The same individual was able to produce wider or narrower enveloping areas in the same level along its course. In such cases, the use of this ichnotaxobase even at the ichnospecific level seems questionable. © 2017 Elsevier Ltd 2018 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01956671_v81_n_p51_Fernandez http://hdl.handle.net/20.500.12110/paper_01956671_v81_n_p51_Fernandez
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Cretaceous
Ethology
Marginal marine
Nereites
South America
Tracemaker
Cretaceous
facies analysis
ichnology
marginal sea
morphology
paleoenvironment
taxonomy
trace fossil
Patagonia
Nereites
spellingShingle Cretaceous
Ethology
Marginal marine
Nereites
South America
Tracemaker
Cretaceous
facies analysis
ichnology
marginal sea
morphology
paleoenvironment
taxonomy
trace fossil
Patagonia
Nereites
Nereites in Lower Cretaceous marginal-marine facies from Patagonia: Ichnotaxonomic and ethological implications
topic_facet Cretaceous
Ethology
Marginal marine
Nereites
South America
Tracemaker
Cretaceous
facies analysis
ichnology
marginal sea
morphology
paleoenvironment
taxonomy
trace fossil
Patagonia
Nereites
description Detailed descriptions of Nereites are uncommon. In this work, Nereites are thoroughly described from tidally influenced and wave dominated deposits in the Cretaceous of the Neuquén Basin (northern Patagonia). These Nereites show a great morphological variety in bedding-plane view. The application of different possible tracemakers for this renowned ichnogenus is discussed. Besides the well known morphology consisting of median tunnel surrounded by a halo composed of reworked material, a tripartite burrow structure has been observed that comprises in addition a disturbed, but not reworked zone at the external side of the reworking halo. The studied material provides evidence that the producers of these Nereites were shallow infaunal deposit-feeding organisms, a feeding strategy mentioned in many studies of the ichnogenus as matching a worm-like tracemaker, while the subsurface characteristics, particularly the disturbed outer zone, support a burrowing arthropod as tracemaker. Consequently, for interpretation of the potential trace producer, basic feeding strategy and burrow construction method should be differentiated and neither should be automatically linked with one particular tracemaker. The different morphologies of these Nereites allow referral of part of this material to N. missouriensis, but some cases of transitional forms remain problematic. The ratio between the width of the median tunnel and the enveloping zone (used as an ichnotaxobase) is not always due to variation in the burrowing depth of the producer. The same individual was able to produce wider or narrower enveloping areas in the same level along its course. In such cases, the use of this ichnotaxobase even at the ichnospecific level seems questionable. © 2017 Elsevier Ltd
title Nereites in Lower Cretaceous marginal-marine facies from Patagonia: Ichnotaxonomic and ethological implications
title_short Nereites in Lower Cretaceous marginal-marine facies from Patagonia: Ichnotaxonomic and ethological implications
title_full Nereites in Lower Cretaceous marginal-marine facies from Patagonia: Ichnotaxonomic and ethological implications
title_fullStr Nereites in Lower Cretaceous marginal-marine facies from Patagonia: Ichnotaxonomic and ethological implications
title_full_unstemmed Nereites in Lower Cretaceous marginal-marine facies from Patagonia: Ichnotaxonomic and ethological implications
title_sort nereites in lower cretaceous marginal-marine facies from patagonia: ichnotaxonomic and ethological implications
publishDate 2018
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01956671_v81_n_p51_Fernandez
http://hdl.handle.net/20.500.12110/paper_01956671_v81_n_p51_Fernandez
_version_ 1768541795069722624