The postcranial anatomy of Yacarerani boliviensis and the phylogenetic significance of the notosuchian postcranial skeleton

In this contribution, we describe new specimens of Yacarerani boliviensis from the Cajones Formation (Upper Cretaceous) of Bolivia. We focus on the postcranial anatomy of Y. boliviensis, because this anatomical region is completely unknown in other sphagesaurid notosuchians up to the present. At lea...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Leardi, Juan Martin, Pol, Diego
Publicado: 2015
Materias:
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02724634_v35_n6_p_Leardi
http://hdl.handle.net/20.500.12110/paper_02724634_v35_n6_p_Leardi
Aporte de:
id paper:paper_02724634_v35_n6_p_Leardi
record_format dspace
spelling paper:paper_02724634_v35_n6_p_Leardi2023-06-08T15:25:14Z The postcranial anatomy of Yacarerani boliviensis and the phylogenetic significance of the notosuchian postcranial skeleton Leardi, Juan Martin Pol, Diego anatomy cladistics cranium Cretaceous crocodilian fossil record new record paleontology phylogenetics skeleton Bolivia Mesoeucrocodylia In this contribution, we describe new specimens of Yacarerani boliviensis from the Cajones Formation (Upper Cretaceous) of Bolivia. We focus on the postcranial anatomy of Y. boliviensis, because this anatomical region is completely unknown in other sphagesaurid notosuchians up to the present. At least eight individuals representing almost the entire postcranial skeleton are described. Although the postcranial anatomy of Yacarerani resembles that of other notosuchians in many features, five autapomorphic characters were identified: pedicles of the atlas bearing a lateral bulge; absence of rounded depressions on the dorsal surface of the anterior to middle dorsal vertebrae; coracoid bearing an oblique crest on its lateral surface; lateromedially compressed anterior ungual phalanges; and femur with a shallow depression for the M. puboischiofemoralis internus 1 and M. caudifemoralis longus. Observed variation in the postcranial anatomy of basal mesoeucrocodylians was incorporated as new characters in a phylogenetic analysis, expanding the postcranial information used in current phylogenetic data sets. The phylogenetic analysis depicts Yacarerani forming a clade with Adamantinasuchus, which is positioned at the base of Sphagesauridae. This family is well nested among a clade of 'advanced notosuchians,' and Mariliasuchus is recovered as its sister group. The cladistic analysis recovered new postcranial synapomorphies for Notosuchia and less inclusive clades, although the fact that many taxa lack postcranial remains limits the number of unambiguous postcranial synapomorphies within Notosuchia. © 2015 by the Society of Vertebrate Paleontology. Fil:Leardi, J.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Pol, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2015 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02724634_v35_n6_p_Leardi http://hdl.handle.net/20.500.12110/paper_02724634_v35_n6_p_Leardi
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic anatomy
cladistics
cranium
Cretaceous
crocodilian
fossil record
new record
paleontology
phylogenetics
skeleton
Bolivia
Mesoeucrocodylia
spellingShingle anatomy
cladistics
cranium
Cretaceous
crocodilian
fossil record
new record
paleontology
phylogenetics
skeleton
Bolivia
Mesoeucrocodylia
Leardi, Juan Martin
Pol, Diego
The postcranial anatomy of Yacarerani boliviensis and the phylogenetic significance of the notosuchian postcranial skeleton
topic_facet anatomy
cladistics
cranium
Cretaceous
crocodilian
fossil record
new record
paleontology
phylogenetics
skeleton
Bolivia
Mesoeucrocodylia
description In this contribution, we describe new specimens of Yacarerani boliviensis from the Cajones Formation (Upper Cretaceous) of Bolivia. We focus on the postcranial anatomy of Y. boliviensis, because this anatomical region is completely unknown in other sphagesaurid notosuchians up to the present. At least eight individuals representing almost the entire postcranial skeleton are described. Although the postcranial anatomy of Yacarerani resembles that of other notosuchians in many features, five autapomorphic characters were identified: pedicles of the atlas bearing a lateral bulge; absence of rounded depressions on the dorsal surface of the anterior to middle dorsal vertebrae; coracoid bearing an oblique crest on its lateral surface; lateromedially compressed anterior ungual phalanges; and femur with a shallow depression for the M. puboischiofemoralis internus 1 and M. caudifemoralis longus. Observed variation in the postcranial anatomy of basal mesoeucrocodylians was incorporated as new characters in a phylogenetic analysis, expanding the postcranial information used in current phylogenetic data sets. The phylogenetic analysis depicts Yacarerani forming a clade with Adamantinasuchus, which is positioned at the base of Sphagesauridae. This family is well nested among a clade of 'advanced notosuchians,' and Mariliasuchus is recovered as its sister group. The cladistic analysis recovered new postcranial synapomorphies for Notosuchia and less inclusive clades, although the fact that many taxa lack postcranial remains limits the number of unambiguous postcranial synapomorphies within Notosuchia. © 2015 by the Society of Vertebrate Paleontology.
author Leardi, Juan Martin
Pol, Diego
author_facet Leardi, Juan Martin
Pol, Diego
author_sort Leardi, Juan Martin
title The postcranial anatomy of Yacarerani boliviensis and the phylogenetic significance of the notosuchian postcranial skeleton
title_short The postcranial anatomy of Yacarerani boliviensis and the phylogenetic significance of the notosuchian postcranial skeleton
title_full The postcranial anatomy of Yacarerani boliviensis and the phylogenetic significance of the notosuchian postcranial skeleton
title_fullStr The postcranial anatomy of Yacarerani boliviensis and the phylogenetic significance of the notosuchian postcranial skeleton
title_full_unstemmed The postcranial anatomy of Yacarerani boliviensis and the phylogenetic significance of the notosuchian postcranial skeleton
title_sort postcranial anatomy of yacarerani boliviensis and the phylogenetic significance of the notosuchian postcranial skeleton
publishDate 2015
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02724634_v35_n6_p_Leardi
http://hdl.handle.net/20.500.12110/paper_02724634_v35_n6_p_Leardi
work_keys_str_mv AT leardijuanmartin thepostcranialanatomyofyacareraniboliviensisandthephylogeneticsignificanceofthenotosuchianpostcranialskeleton
AT poldiego thepostcranialanatomyofyacareraniboliviensisandthephylogeneticsignificanceofthenotosuchianpostcranialskeleton
AT leardijuanmartin postcranialanatomyofyacareraniboliviensisandthephylogeneticsignificanceofthenotosuchianpostcranialskeleton
AT poldiego postcranialanatomyofyacareraniboliviensisandthephylogeneticsignificanceofthenotosuchianpostcranialskeleton
_version_ 1768541608211382272