A new small short-snouted dyrosaurid (crocodylomorpha, mesoeucrocodylia) from the paleocene of northeastern Colombia

The fossil record of dyrosaurid crocodyliforms spans the Late Cretaceous to Middle Eocene of Africa, Asia, Europe, North America, and South America. Prior to this study, specimens from South America have been limited to a few fossils with only two taxa diagnosed. We describe a nearly complete skull...

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Autores Principales: Hastings, Alexander K., Bloch, Jonathan I., Cadena, Edwin A., Jaramillo, Carlos A.
Formato: Artículo (Article)
Lenguaje:Inglés (English)
Publicado: Society of Vertebrate Paleontology 2010
Materias:
Acceso en línea:https://repository.urosario.edu.co/handle/10336/27642
https://doi.org/10.1080/02724630903409204
id ir-10336-27642
recordtype dspace
spelling ir-10336-276422020-08-19T14:43:07Z A new small short-snouted dyrosaurid (crocodylomorpha, mesoeucrocodylia) from the paleocene of northeastern Colombia Un nuevo disprosáurido pequeño de hocico corto (crocodylomorpha, mesoeucrocodylia) del paleoceno del noreste de Colombia Hastings, Alexander K. Bloch, Jonathan I. Cadena, Edwin A. Jaramillo, Carlos A. Fossil Colombia Dyrosauridae The fossil record of dyrosaurid crocodyliforms spans the Late Cretaceous to Middle Eocene of Africa, Asia, Europe, North America, and South America. Prior to this study, specimens from South America have been limited to a few fossils with only two taxa diagnosed. We describe a nearly complete skull and unassociated mandible of a new dyrosaurid, Cerrejonisuchus improcerus gen. et sp. nov., from the Paleocene Cerrejón Formation of northeastern Colombia. The skull of C. improcerus has relatively elongate supratemporal fenestrae and well-developed occipital tuberosities, both diagnostic characteristics of Dyrosauridae. The rostrum of adult C. improcerus comprises 54–59% of the length of the skull, making it the shortest snout of any known dyrosaurid. A cladistic analysis using 82 cranial and mandibular characters for all species of Dyrosauridae known from crania yielded two most-parsimonious cladograms with C. improcerus as the sister taxon to a clade including Arambourgisuchus, Dyrosaurus, Hyposaurus, Congosaurus, Rhabdognathus, Atlantosuchus, and Guarinisuchus. Only Chenanisuchus, Sokotosuchus, and Phosphatosaurus, all known only from Africa, are more primitive within Dyrosauridae. Chenanisuchus from the Paleocene of Morocco, the only other known short-snouted dyrosaurid, is not closely related to C. improcerus and a short-snouted condition appears to have evolved independently at least twice within Dyrosauridae. Our analysis supports an African origin of Dyrosauridae with dispersals to the New World by the Late Cretaceous or earliest Paleocene. The presence of C. improcerus, together with undescribed taxa from the Cerrejón Formation, suggests a radiation of dyrosaurid crocodyliforms, possibly following the K-P boundary, in tropical South America. 2010-01-28 2020-08-19T14:43:07Z info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion ISSN: 0272-4634 EISSN: 1937-2809 https://repository.urosario.edu.co/handle/10336/27642 https://doi.org/10.1080/02724630903409204 eng info:eu-repo/semantics/openAccess application/pdf Society of Vertebrate Paleontology Taylor & Francis Group Journal of Vertebrate Paleontology
institution EdocUR - Universidad del Rosario
collection DSpace
language Inglés (English)
topic Fossil
Colombia
Dyrosauridae
spellingShingle Fossil
Colombia
Dyrosauridae
Hastings, Alexander K.
Bloch, Jonathan I.
Cadena, Edwin A.
Jaramillo, Carlos A.
A new small short-snouted dyrosaurid (crocodylomorpha, mesoeucrocodylia) from the paleocene of northeastern Colombia
description The fossil record of dyrosaurid crocodyliforms spans the Late Cretaceous to Middle Eocene of Africa, Asia, Europe, North America, and South America. Prior to this study, specimens from South America have been limited to a few fossils with only two taxa diagnosed. We describe a nearly complete skull and unassociated mandible of a new dyrosaurid, Cerrejonisuchus improcerus gen. et sp. nov., from the Paleocene Cerrejón Formation of northeastern Colombia. The skull of C. improcerus has relatively elongate supratemporal fenestrae and well-developed occipital tuberosities, both diagnostic characteristics of Dyrosauridae. The rostrum of adult C. improcerus comprises 54–59% of the length of the skull, making it the shortest snout of any known dyrosaurid. A cladistic analysis using 82 cranial and mandibular characters for all species of Dyrosauridae known from crania yielded two most-parsimonious cladograms with C. improcerus as the sister taxon to a clade including Arambourgisuchus, Dyrosaurus, Hyposaurus, Congosaurus, Rhabdognathus, Atlantosuchus, and Guarinisuchus. Only Chenanisuchus, Sokotosuchus, and Phosphatosaurus, all known only from Africa, are more primitive within Dyrosauridae. Chenanisuchus from the Paleocene of Morocco, the only other known short-snouted dyrosaurid, is not closely related to C. improcerus and a short-snouted condition appears to have evolved independently at least twice within Dyrosauridae. Our analysis supports an African origin of Dyrosauridae with dispersals to the New World by the Late Cretaceous or earliest Paleocene. The presence of C. improcerus, together with undescribed taxa from the Cerrejón Formation, suggests a radiation of dyrosaurid crocodyliforms, possibly following the K-P boundary, in tropical South America.
format Artículo (Article)
author Hastings, Alexander K.
Bloch, Jonathan I.
Cadena, Edwin A.
Jaramillo, Carlos A.
author_facet Hastings, Alexander K.
Bloch, Jonathan I.
Cadena, Edwin A.
Jaramillo, Carlos A.
author_sort Hastings, Alexander K.
title A new small short-snouted dyrosaurid (crocodylomorpha, mesoeucrocodylia) from the paleocene of northeastern Colombia
title_short A new small short-snouted dyrosaurid (crocodylomorpha, mesoeucrocodylia) from the paleocene of northeastern Colombia
title_full A new small short-snouted dyrosaurid (crocodylomorpha, mesoeucrocodylia) from the paleocene of northeastern Colombia
title_fullStr A new small short-snouted dyrosaurid (crocodylomorpha, mesoeucrocodylia) from the paleocene of northeastern Colombia
title_full_unstemmed A new small short-snouted dyrosaurid (crocodylomorpha, mesoeucrocodylia) from the paleocene of northeastern Colombia
title_sort new small short-snouted dyrosaurid (crocodylomorpha, mesoeucrocodylia) from the paleocene of northeastern colombia
publisher Society of Vertebrate Paleontology
publishDate 2010
url https://repository.urosario.edu.co/handle/10336/27642
https://doi.org/10.1080/02724630903409204
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