A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW Argentina

Autores
Von Baczko, Belen; Ezcurra, Martin Daniel; Lecuona, Agustina; Desojo, Julia Brenda
Año de publicación
2023
Idioma
inglés
Tipo de recurso
documento de conferencia
Estado
versión publicada
Descripción
The lower member of the Chañares Formation yields one of the richest Middle-early Late Triassic continental tetrapod faunas worldwide and is subdivided in two assemblage zones (AZ): the stratigraphically lower Tarjadia AZ and the upper Massetognathus-Chanaresuchus AZ. The former is represented by dicynodonts, cynodonts, rhynchosaurs, and pseudosuchian archosaurs, whereas the latter is composed of dicynodonts, cynodonts, proterochampsians, and dinosauromorph, pterosauromorph, and pseudosuchian archosaurs. The pseudosuchian record consists of the ‘rauisuchian’ Luperosuchus fractus, indeterminate suchians, and the erpetosuchid Tarjadia ruthae in the Tarjadia AZ and the gracilisuchid Gracilisuchus stipanicicorum in the Massetognathus-Chanaresuchus AZ. Here we revisit the taxonomy of a putative juvenile specimen of L. fractus (PULR-V 057) consisting of a partial skull, but was subsequently preliminary reinterpreted as taxonomically distinct. We recognize that most of the diagnostic features of Luperosuchus fractus are absent in PULR-V 057. By contrast, the presence of the following character-states allows us to reinterpret PULR-V 057 as a Gracilisuchidae: premaxilla with posterodorsal process that fits into slot on lateral surface of nasal; nasal forms part of dorsal border of antorbital fossa; and frontal with anterior portion that tapers anteriorly along midline. Additionally, PULR-V 057 shares with G. stipanicicorum, but not with other gracilisuchids, a straight posterior edge of the postorbital process of jugal, absence of palatal teeth, and horizontal process of the maxilla with parallel dorsal and ventral margins. In particular, the first feature has been proposed as an autapomorphy of G. stipanicicorum. Nevertheless, PULR-V 057 differs from G. stipanicicorum in the presence of a maxilla with an ascending process slanting more posterodorsally, lower maxillary tooth count, absence of ornamentation on external surface of nasal and frontal, and thicker tuberosity on the main body of jugal. A preliminary phylogenetic analysis recovered PULR-V 057 as the sister taxon to G. stipanicicorum. It is noteworthy that PULR-V 057 is twice larger than known specimens of G. stipanicicorum and comes from the same AZ because of its preservational features, making it the largest archosaur specimen described for the Massetognathus-Chanaresuchus AZ. Thus, future research will focus on determining if PULR-V 057 is a more mature specimen of G. stipanicicorum or a different gracilisuchid species. In conclusion, we expand the ecomorphological diversity of gracilisuchids in the Chañares Formation to include medium-sized predatory forms, we agree with previous authors to restrict the hypodigm of L. fractus only to its holotype (PULR-V 04) but also restrict its stratigraphic range to the Tarjadia AZ.
Fil: Von Baczko, Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina
Fil: Ezcurra, Martin Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina
Fil: Lecuona, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentina
Fil: Desojo, Julia Brenda. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina
Reunión de Comunicaciones de la Asociación Paleontológica Argentina 2023
Argentina
Universidad Nacional de Rio Negro
Asociación Paleontológica Argentina
Materia
Pseudosuchia
Anatomy
Taxonomy
Gracilisuchidae
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nd/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/267415
Acceder
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network_name_str CONICET Digital (CONICET)
spelling A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW ArgentinaVon Baczko, BelenEzcurra, Martin DanielLecuona, AgustinaDesojo, Julia BrendaPseudosuchiaAnatomyTaxonomyGracilisuchidaehttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1The lower member of the Chañares Formation yields one of the richest Middle-early Late Triassic continental tetrapod faunas worldwide and is subdivided in two assemblage zones (AZ): the stratigraphically lower Tarjadia AZ and the upper Massetognathus-Chanaresuchus AZ. The former is represented by dicynodonts, cynodonts, rhynchosaurs, and pseudosuchian archosaurs, whereas the latter is composed of dicynodonts, cynodonts, proterochampsians, and dinosauromorph, pterosauromorph, and pseudosuchian archosaurs. The pseudosuchian record consists of the ‘rauisuchian’ Luperosuchus fractus, indeterminate suchians, and the erpetosuchid Tarjadia ruthae in the Tarjadia AZ and the gracilisuchid Gracilisuchus stipanicicorum in the Massetognathus-Chanaresuchus AZ. Here we revisit the taxonomy of a putative juvenile specimen of L. fractus (PULR-V 057) consisting of a partial skull, but was subsequently preliminary reinterpreted as taxonomically distinct. We recognize that most of the diagnostic features of Luperosuchus fractus are absent in PULR-V 057. By contrast, the presence of the following character-states allows us to reinterpret PULR-V 057 as a Gracilisuchidae: premaxilla with posterodorsal process that fits into slot on lateral surface of nasal; nasal forms part of dorsal border of antorbital fossa; and frontal with anterior portion that tapers anteriorly along midline. Additionally, PULR-V 057 shares with G. stipanicicorum, but not with other gracilisuchids, a straight posterior edge of the postorbital process of jugal, absence of palatal teeth, and horizontal process of the maxilla with parallel dorsal and ventral margins. In particular, the first feature has been proposed as an autapomorphy of G. stipanicicorum. Nevertheless, PULR-V 057 differs from G. stipanicicorum in the presence of a maxilla with an ascending process slanting more posterodorsally, lower maxillary tooth count, absence of ornamentation on external surface of nasal and frontal, and thicker tuberosity on the main body of jugal. A preliminary phylogenetic analysis recovered PULR-V 057 as the sister taxon to G. stipanicicorum. It is noteworthy that PULR-V 057 is twice larger than known specimens of G. stipanicicorum and comes from the same AZ because of its preservational features, making it the largest archosaur specimen described for the Massetognathus-Chanaresuchus AZ. Thus, future research will focus on determining if PULR-V 057 is a more mature specimen of G. stipanicicorum or a different gracilisuchid species. In conclusion, we expand the ecomorphological diversity of gracilisuchids in the Chañares Formation to include medium-sized predatory forms, we agree with previous authors to restrict the hypodigm of L. fractus only to its holotype (PULR-V 04) but also restrict its stratigraphic range to the Tarjadia AZ.Fil: Von Baczko, Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Ezcurra, Martin Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Lecuona, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Desojo, Julia Brenda. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaReunión de Comunicaciones de la Asociación Paleontológica Argentina 2023ArgentinaUniversidad Nacional de Rio NegroAsociación Paleontológica ArgentinaAsociación Paleontológica Argentina2023info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/conferenceObjectReuniónBookhttp://purl.org/coar/resource_type/c_5794info:ar-repo/semantics/documentoDeConferenciaapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/267415A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW Argentina; Reunión de Comunicaciones de la Asociación Paleontológica Argentina 2023; Argentina; 2023; 162-1622469-0228CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://peapaleontologica.org.ar/index.php/peapa/article/view/502info:eu-repo/semantics/altIdentifier/doi/10.5710/PEAPA.04.04.2024.502Nacionalinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nd/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T10:02:11Zoai:ri.conicet.gov.ar:11336/267415instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-03 10:02:11.478CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW Argentina
title A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW Argentina
spellingShingle A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW Argentina
Von Baczko, Belen
Pseudosuchia
Anatomy
Taxonomy
Gracilisuchidae
title_short A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW Argentina
title_full A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW Argentina
title_fullStr A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW Argentina
title_full_unstemmed A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW Argentina
title_sort A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW Argentina
dc.creator.none.fl_str_mv Von Baczko, Belen
Ezcurra, Martin Daniel
Lecuona, Agustina
Desojo, Julia Brenda
author Von Baczko, Belen
author_facet Von Baczko, Belen
Ezcurra, Martin Daniel
Lecuona, Agustina
Desojo, Julia Brenda
author_role author
author2 Ezcurra, Martin Daniel
Lecuona, Agustina
Desojo, Julia Brenda
author2_role author
author
author
dc.subject.none.fl_str_mv Pseudosuchia
Anatomy
Taxonomy
Gracilisuchidae
topic Pseudosuchia
Anatomy
Taxonomy
Gracilisuchidae
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv The lower member of the Chañares Formation yields one of the richest Middle-early Late Triassic continental tetrapod faunas worldwide and is subdivided in two assemblage zones (AZ): the stratigraphically lower Tarjadia AZ and the upper Massetognathus-Chanaresuchus AZ. The former is represented by dicynodonts, cynodonts, rhynchosaurs, and pseudosuchian archosaurs, whereas the latter is composed of dicynodonts, cynodonts, proterochampsians, and dinosauromorph, pterosauromorph, and pseudosuchian archosaurs. The pseudosuchian record consists of the ‘rauisuchian’ Luperosuchus fractus, indeterminate suchians, and the erpetosuchid Tarjadia ruthae in the Tarjadia AZ and the gracilisuchid Gracilisuchus stipanicicorum in the Massetognathus-Chanaresuchus AZ. Here we revisit the taxonomy of a putative juvenile specimen of L. fractus (PULR-V 057) consisting of a partial skull, but was subsequently preliminary reinterpreted as taxonomically distinct. We recognize that most of the diagnostic features of Luperosuchus fractus are absent in PULR-V 057. By contrast, the presence of the following character-states allows us to reinterpret PULR-V 057 as a Gracilisuchidae: premaxilla with posterodorsal process that fits into slot on lateral surface of nasal; nasal forms part of dorsal border of antorbital fossa; and frontal with anterior portion that tapers anteriorly along midline. Additionally, PULR-V 057 shares with G. stipanicicorum, but not with other gracilisuchids, a straight posterior edge of the postorbital process of jugal, absence of palatal teeth, and horizontal process of the maxilla with parallel dorsal and ventral margins. In particular, the first feature has been proposed as an autapomorphy of G. stipanicicorum. Nevertheless, PULR-V 057 differs from G. stipanicicorum in the presence of a maxilla with an ascending process slanting more posterodorsally, lower maxillary tooth count, absence of ornamentation on external surface of nasal and frontal, and thicker tuberosity on the main body of jugal. A preliminary phylogenetic analysis recovered PULR-V 057 as the sister taxon to G. stipanicicorum. It is noteworthy that PULR-V 057 is twice larger than known specimens of G. stipanicicorum and comes from the same AZ because of its preservational features, making it the largest archosaur specimen described for the Massetognathus-Chanaresuchus AZ. Thus, future research will focus on determining if PULR-V 057 is a more mature specimen of G. stipanicicorum or a different gracilisuchid species. In conclusion, we expand the ecomorphological diversity of gracilisuchids in the Chañares Formation to include medium-sized predatory forms, we agree with previous authors to restrict the hypodigm of L. fractus only to its holotype (PULR-V 04) but also restrict its stratigraphic range to the Tarjadia AZ.
Fil: Von Baczko, Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina
Fil: Ezcurra, Martin Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina
Fil: Lecuona, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentina
Fil: Desojo, Julia Brenda. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina
Reunión de Comunicaciones de la Asociación Paleontológica Argentina 2023
Argentina
Universidad Nacional de Rio Negro
Asociación Paleontológica Argentina
description The lower member of the Chañares Formation yields one of the richest Middle-early Late Triassic continental tetrapod faunas worldwide and is subdivided in two assemblage zones (AZ): the stratigraphically lower Tarjadia AZ and the upper Massetognathus-Chanaresuchus AZ. The former is represented by dicynodonts, cynodonts, rhynchosaurs, and pseudosuchian archosaurs, whereas the latter is composed of dicynodonts, cynodonts, proterochampsians, and dinosauromorph, pterosauromorph, and pseudosuchian archosaurs. The pseudosuchian record consists of the ‘rauisuchian’ Luperosuchus fractus, indeterminate suchians, and the erpetosuchid Tarjadia ruthae in the Tarjadia AZ and the gracilisuchid Gracilisuchus stipanicicorum in the Massetognathus-Chanaresuchus AZ. Here we revisit the taxonomy of a putative juvenile specimen of L. fractus (PULR-V 057) consisting of a partial skull, but was subsequently preliminary reinterpreted as taxonomically distinct. We recognize that most of the diagnostic features of Luperosuchus fractus are absent in PULR-V 057. By contrast, the presence of the following character-states allows us to reinterpret PULR-V 057 as a Gracilisuchidae: premaxilla with posterodorsal process that fits into slot on lateral surface of nasal; nasal forms part of dorsal border of antorbital fossa; and frontal with anterior portion that tapers anteriorly along midline. Additionally, PULR-V 057 shares with G. stipanicicorum, but not with other gracilisuchids, a straight posterior edge of the postorbital process of jugal, absence of palatal teeth, and horizontal process of the maxilla with parallel dorsal and ventral margins. In particular, the first feature has been proposed as an autapomorphy of G. stipanicicorum. Nevertheless, PULR-V 057 differs from G. stipanicicorum in the presence of a maxilla with an ascending process slanting more posterodorsally, lower maxillary tooth count, absence of ornamentation on external surface of nasal and frontal, and thicker tuberosity on the main body of jugal. A preliminary phylogenetic analysis recovered PULR-V 057 as the sister taxon to G. stipanicicorum. It is noteworthy that PULR-V 057 is twice larger than known specimens of G. stipanicicorum and comes from the same AZ because of its preservational features, making it the largest archosaur specimen described for the Massetognathus-Chanaresuchus AZ. Thus, future research will focus on determining if PULR-V 057 is a more mature specimen of G. stipanicicorum or a different gracilisuchid species. In conclusion, we expand the ecomorphological diversity of gracilisuchids in the Chañares Formation to include medium-sized predatory forms, we agree with previous authors to restrict the hypodigm of L. fractus only to its holotype (PULR-V 04) but also restrict its stratigraphic range to the Tarjadia AZ.
publishDate 2023
dc.date.none.fl_str_mv 2023
dc.type.none.fl_str_mv info:eu-repo/semantics/publishedVersion
info:eu-repo/semantics/conferenceObject
Reunión
Book
http://purl.org/coar/resource_type/c_5794
info:ar-repo/semantics/documentoDeConferencia
status_str publishedVersion
format conferenceObject
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/267415
A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW Argentina; Reunión de Comunicaciones de la Asociación Paleontológica Argentina 2023; Argentina; 2023; 162-162
2469-0228
CONICET Digital
CONICET
url http://hdl.handle.net/11336/267415
identifier_str_mv A large gracilisuchid from the lower Upper Triassic beds of the Chañares Formation of NW Argentina; Reunión de Comunicaciones de la Asociación Paleontológica Argentina 2023; Argentina; 2023; 162-162
2469-0228
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
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info:eu-repo/semantics/altIdentifier/doi/10.5710/PEAPA.04.04.2024.502
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dc.publisher.none.fl_str_mv Asociación Paleontológica Argentina
publisher.none.fl_str_mv Asociación Paleontológica Argentina
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repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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