Cranial anatomy and neuroanatomical features of a new specimen of Geosaurini (Crocodylomorpha: Metriorhynchidae) from west-central Argentina

Fossil records of Geosaurini taxa in South American margins of the Eastern Pacific are scarce. We describe a new specimen of Geosaurini found in sedimentites of the Vaca Muerta Formation (Substeueroceras koeneni Biozone, uppermost Tithonian–lowermost Berriasian) and referred it as Dakosaurus cf. D....

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Detalles Bibliográficos
Publicado: 2015
Materias:
Berriasian
Dakosaurus
Neuquén Basin
Thalattosuchia
Tithonian
anatomy
biostratigraphy
biozonation
body shape
cranium
crocodilian
fossil record
new record
paleontology
species occurrence
taxonomy
Argentina
Crocodylomorpha
Metriorhynchidae
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08912963_v27_n1_p33_Herrera
http://hdl.handle.net/20.500.12110/paper_08912963_v27_n1_p33_Herrera
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_08912963_v27_n1_p33_Herrera
record_format dspace
spelling paper:paper_08912963_v27_n1_p33_Herrera2023-06-08T15:47:10Z Cranial anatomy and neuroanatomical features of a new specimen of Geosaurini (Crocodylomorpha: Metriorhynchidae) from west-central Argentina Berriasian Dakosaurus Neuquén Basin Thalattosuchia Tithonian anatomy Berriasian biostratigraphy biozonation body shape cranium crocodilian fossil record new record paleontology species occurrence taxonomy Tithonian Argentina Crocodylomorpha Metriorhynchidae Thalattosuchia Fossil records of Geosaurini taxa in South American margins of the Eastern Pacific are scarce. We describe a new specimen of Geosaurini found in sedimentites of the Vaca Muerta Formation (Substeueroceras koeneni Biozone, uppermost Tithonian–lowermost Berriasian) and referred it as Dakosaurus cf. D. andiniensis. The close stratigraphic association of this specimen with late Tithonian to early Berriasian ammonoids allows confirming with biostratigraphic accuracy that, up to date, the first known occurrence of the Geosaurini taxa in South America is in late Tithonian. The specimen consists of a partially preserved skull and a partially exposed natural endocast of the brain cavity. This work is the first detailed description of a natural endocast of a metriorhynchid. The conspicuous blood vessel fillings covering almost all the dorsal surface of the cerebral hemispheres suggest that the dural envelope of this region was thin and that the cerebral hemispheres filled most of the cavity. A large dorsal venous sinus that overlays the dorsal region of the hindbrain, a tube-like cavity connecting the cranioquadrate passage and an enlarged internal carotid canal, previously described for ‘Metriorhynchus’ cf. ‘M.’ westermanni and present in Dakosaurus cf. D. andiniensis, suggest that these features were more widely distributed within metriorhynchids. © 2015, © 2014 Taylor & Francis. 2015 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08912963_v27_n1_p33_Herrera http://hdl.handle.net/20.500.12110/paper_08912963_v27_n1_p33_Herrera
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Berriasian
Dakosaurus
Neuquén Basin
Thalattosuchia
Tithonian
anatomy
Berriasian
biostratigraphy
biozonation
body shape
cranium
crocodilian
fossil record
new record
paleontology
species occurrence
taxonomy
Tithonian
Argentina
Crocodylomorpha
Metriorhynchidae
Thalattosuchia
spellingShingle Berriasian
Dakosaurus
Neuquén Basin
Thalattosuchia
Tithonian
anatomy
Berriasian
biostratigraphy
biozonation
body shape
cranium
crocodilian
fossil record
new record
paleontology
species occurrence
taxonomy
Tithonian
Argentina
Crocodylomorpha
Metriorhynchidae
Thalattosuchia
Cranial anatomy and neuroanatomical features of a new specimen of Geosaurini (Crocodylomorpha: Metriorhynchidae) from west-central Argentina
topic_facet Berriasian
Dakosaurus
Neuquén Basin
Thalattosuchia
Tithonian
anatomy
Berriasian
biostratigraphy
biozonation
body shape
cranium
crocodilian
fossil record
new record
paleontology
species occurrence
taxonomy
Tithonian
Argentina
Crocodylomorpha
Metriorhynchidae
Thalattosuchia
description Fossil records of Geosaurini taxa in South American margins of the Eastern Pacific are scarce. We describe a new specimen of Geosaurini found in sedimentites of the Vaca Muerta Formation (Substeueroceras koeneni Biozone, uppermost Tithonian–lowermost Berriasian) and referred it as Dakosaurus cf. D. andiniensis. The close stratigraphic association of this specimen with late Tithonian to early Berriasian ammonoids allows confirming with biostratigraphic accuracy that, up to date, the first known occurrence of the Geosaurini taxa in South America is in late Tithonian. The specimen consists of a partially preserved skull and a partially exposed natural endocast of the brain cavity. This work is the first detailed description of a natural endocast of a metriorhynchid. The conspicuous blood vessel fillings covering almost all the dorsal surface of the cerebral hemispheres suggest that the dural envelope of this region was thin and that the cerebral hemispheres filled most of the cavity. A large dorsal venous sinus that overlays the dorsal region of the hindbrain, a tube-like cavity connecting the cranioquadrate passage and an enlarged internal carotid canal, previously described for ‘Metriorhynchus’ cf. ‘M.’ westermanni and present in Dakosaurus cf. D. andiniensis, suggest that these features were more widely distributed within metriorhynchids. © 2015, © 2014 Taylor & Francis.
title Cranial anatomy and neuroanatomical features of a new specimen of Geosaurini (Crocodylomorpha: Metriorhynchidae) from west-central Argentina
title_short Cranial anatomy and neuroanatomical features of a new specimen of Geosaurini (Crocodylomorpha: Metriorhynchidae) from west-central Argentina
title_full Cranial anatomy and neuroanatomical features of a new specimen of Geosaurini (Crocodylomorpha: Metriorhynchidae) from west-central Argentina
title_fullStr Cranial anatomy and neuroanatomical features of a new specimen of Geosaurini (Crocodylomorpha: Metriorhynchidae) from west-central Argentina
title_full_unstemmed Cranial anatomy and neuroanatomical features of a new specimen of Geosaurini (Crocodylomorpha: Metriorhynchidae) from west-central Argentina
title_sort cranial anatomy and neuroanatomical features of a new specimen of geosaurini (crocodylomorpha: metriorhynchidae) from west-central argentina
publishDate 2015
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08912963_v27_n1_p33_Herrera
http://hdl.handle.net/20.500.12110/paper_08912963_v27_n1_p33_Herrera
_version_ 1768541994339008512

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