Filling a key gap in growth patterns of Pseudosuchia through the osteohistology of Dynamosuchus collisensis (Ornithosuchidae: Archosauria)

Autores
Farias, Brodsky Dantas Macedo; Müller, Rodrigo Temp; Prestes de Bem, Fabiula; Baczko, M. Belén von; Desojo, Julia Brenda; Soares, Marina Bento
Año de publicación
2026
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Ornithosuchidae are among the least studied pseudosuchians from a histological perspective. We present the first long-bone osteohistological data for the ornithosuchid Dynamosuchus collisensis, based on mid-diaphyseal thin sections of the humerus and femur, supplemented by a rib. The long bones show cortices dominated by highly vascularized woven– parallel complex and parallel-fibred bone, with three well- defined annuli and a fourth incipient one near the periosteal margin. Medullary expansion occurs through endosteal resorption, and secondary osteons in formation are present. The rib displays lower vascularization, suggesting reduced growth rates in axial elements. Open neurocentral sutures, the absence of an EFS and the lack of peripheral slowdown in cortical deposition indicate that the holotype was skeletally immature, and probably sexually immature, at the time of death. This suggests that the individual had not yet reached its maximum body size and would probably have attained a larger size, consistent with a role as a top-tier predator in Carnian ecosystems. These features support sustained rapid growth, contrasting with the predominantly slow growth of late-diverging crocodylomorphs and more closely resembling early loricatans and poposauroids. Because Ornithosuchidae occupy an early-diverging position within Pseudosuchia, these data support the hypothesis that fast growth may represent a plesiomorphic condition within the clade.
Facultad de Ciencias Naturales y Museo
Materia
Paleontología
Triassic
Bone histology
Hyperodapedon Assemblage Zone
Ontogeny
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/195603
Acceder
id SEDICI_c8d4fc721c419599de0c0d5aba409618
oai_identifier_str oai:sedici.unlp.edu.ar:10915/195603
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling Filling a key gap in growth patterns of Pseudosuchia through the osteohistology of Dynamosuchus collisensis (Ornithosuchidae: Archosauria)Farias, Brodsky Dantas MacedoMüller, Rodrigo TempPrestes de Bem, FabiulaBaczko, M. Belén vonDesojo, Julia BrendaSoares, Marina BentoPaleontologíaTriassicBone histologyHyperodapedon Assemblage ZoneOntogenyOrnithosuchidae are among the least studied pseudosuchians from a histological perspective. We present the first long-bone osteohistological data for the ornithosuchid Dynamosuchus collisensis, based on mid-diaphyseal thin sections of the humerus and femur, supplemented by a rib. The long bones show cortices dominated by highly vascularized woven– parallel complex and parallel-fibred bone, with three well- defined annuli and a fourth incipient one near the periosteal margin. Medullary expansion occurs through endosteal resorption, and secondary osteons in formation are present. The rib displays lower vascularization, suggesting reduced growth rates in axial elements. Open neurocentral sutures, the absence of an EFS and the lack of peripheral slowdown in cortical deposition indicate that the holotype was skeletally immature, and probably sexually immature, at the time of death. This suggests that the individual had not yet reached its maximum body size and would probably have attained a larger size, consistent with a role as a top-tier predator in Carnian ecosystems. These features support sustained rapid growth, contrasting with the predominantly slow growth of late-diverging crocodylomorphs and more closely resembling early loricatans and poposauroids. Because Ornithosuchidae occupy an early-diverging position within Pseudosuchia, these data support the hypothesis that fast growth may represent a plesiomorphic condition within the clade.Facultad de Ciencias Naturales y Museo2026-02info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfhttp://sedici.unlp.edu.ar/handle/10915/195603enginfo:eu-repo/semantics/altIdentifier/issn/2054-5703info:eu-repo/semantics/altIdentifier/doi/10.1098/rsos.252042info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International (CC BY 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2026-06-23T11:17:06Zoai:sedici.unlp.edu.ar:10915/195603Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292026-06-23 11:17:06.905SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Filling a key gap in growth patterns of Pseudosuchia through the osteohistology of Dynamosuchus collisensis (Ornithosuchidae: Archosauria)
title Filling a key gap in growth patterns of Pseudosuchia through the osteohistology of Dynamosuchus collisensis (Ornithosuchidae: Archosauria)
spellingShingle Filling a key gap in growth patterns of Pseudosuchia through the osteohistology of Dynamosuchus collisensis (Ornithosuchidae: Archosauria)
Farias, Brodsky Dantas Macedo
Paleontología
Triassic
Bone histology
Hyperodapedon Assemblage Zone
Ontogeny
title_short Filling a key gap in growth patterns of Pseudosuchia through the osteohistology of Dynamosuchus collisensis (Ornithosuchidae: Archosauria)
title_full Filling a key gap in growth patterns of Pseudosuchia through the osteohistology of Dynamosuchus collisensis (Ornithosuchidae: Archosauria)
title_fullStr Filling a key gap in growth patterns of Pseudosuchia through the osteohistology of Dynamosuchus collisensis (Ornithosuchidae: Archosauria)
title_full_unstemmed Filling a key gap in growth patterns of Pseudosuchia through the osteohistology of Dynamosuchus collisensis (Ornithosuchidae: Archosauria)
title_sort Filling a key gap in growth patterns of Pseudosuchia through the osteohistology of Dynamosuchus collisensis (Ornithosuchidae: Archosauria)
dc.creator.none.fl_str_mv Farias, Brodsky Dantas Macedo
Müller, Rodrigo Temp
Prestes de Bem, Fabiula
Baczko, M. Belén von
Desojo, Julia Brenda
Soares, Marina Bento
author Farias, Brodsky Dantas Macedo
author_facet Farias, Brodsky Dantas Macedo
Müller, Rodrigo Temp
Prestes de Bem, Fabiula
Baczko, M. Belén von
Desojo, Julia Brenda
Soares, Marina Bento
author_role author
author2 Müller, Rodrigo Temp
Prestes de Bem, Fabiula
Baczko, M. Belén von
Desojo, Julia Brenda
Soares, Marina Bento
author2_role author
author
author
author
author
dc.subject.none.fl_str_mv Paleontología
Triassic
Bone histology
Hyperodapedon Assemblage Zone
Ontogeny
topic Paleontología
Triassic
Bone histology
Hyperodapedon Assemblage Zone
Ontogeny
dc.description.none.fl_txt_mv Ornithosuchidae are among the least studied pseudosuchians from a histological perspective. We present the first long-bone osteohistological data for the ornithosuchid Dynamosuchus collisensis, based on mid-diaphyseal thin sections of the humerus and femur, supplemented by a rib. The long bones show cortices dominated by highly vascularized woven– parallel complex and parallel-fibred bone, with three well- defined annuli and a fourth incipient one near the periosteal margin. Medullary expansion occurs through endosteal resorption, and secondary osteons in formation are present. The rib displays lower vascularization, suggesting reduced growth rates in axial elements. Open neurocentral sutures, the absence of an EFS and the lack of peripheral slowdown in cortical deposition indicate that the holotype was skeletally immature, and probably sexually immature, at the time of death. This suggests that the individual had not yet reached its maximum body size and would probably have attained a larger size, consistent with a role as a top-tier predator in Carnian ecosystems. These features support sustained rapid growth, contrasting with the predominantly slow growth of late-diverging crocodylomorphs and more closely resembling early loricatans and poposauroids. Because Ornithosuchidae occupy an early-diverging position within Pseudosuchia, these data support the hypothesis that fast growth may represent a plesiomorphic condition within the clade.
Facultad de Ciencias Naturales y Museo
description Ornithosuchidae are among the least studied pseudosuchians from a histological perspective. We present the first long-bone osteohistological data for the ornithosuchid Dynamosuchus collisensis, based on mid-diaphyseal thin sections of the humerus and femur, supplemented by a rib. The long bones show cortices dominated by highly vascularized woven– parallel complex and parallel-fibred bone, with three well- defined annuli and a fourth incipient one near the periosteal margin. Medullary expansion occurs through endosteal resorption, and secondary osteons in formation are present. The rib displays lower vascularization, suggesting reduced growth rates in axial elements. Open neurocentral sutures, the absence of an EFS and the lack of peripheral slowdown in cortical deposition indicate that the holotype was skeletally immature, and probably sexually immature, at the time of death. This suggests that the individual had not yet reached its maximum body size and would probably have attained a larger size, consistent with a role as a top-tier predator in Carnian ecosystems. These features support sustained rapid growth, contrasting with the predominantly slow growth of late-diverging crocodylomorphs and more closely resembling early loricatans and poposauroids. Because Ornithosuchidae occupy an early-diverging position within Pseudosuchia, these data support the hypothesis that fast growth may represent a plesiomorphic condition within the clade.
publishDate 2026
dc.date.none.fl_str_mv 2026-02
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/195603
url http://sedici.unlp.edu.ar/handle/10915/195603
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/2054-5703
info:eu-repo/semantics/altIdentifier/doi/10.1098/rsos.252042
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
_version_ 1868982611547783168
score 13.265058

Publicaciones similares