Mandibles of mastodonsaurid temnospondyls from the Upper Permian-Lower Triassic of Uruguay

Partially preserved temnospondyl mandibles from the Late Permian–Early Triassic Buena Vista Formation of Uruguay are referred to the basal stereospondyl taxon Mastodonsauridae. These represent the earliest known members of this group for South America. In most cases, this assignment was based on the...

Full description

Bibliographic Details
Authors: Piñeiro, Graciela, Marsicano, Claudia Alicia, Damiani, Ross
Format: article
Status:Published version
Publication Date:2007
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/93810
Online Access:http://hdl.handle.net/11336/93810
Access Level:Open access
Keyword:Temnospondyli
Permian-Triassic
Uruguay
Paleobiogeography
https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
Description
Summary:Partially preserved temnospondyl mandibles from the Late Permian–Early Triassic Buena Vista Formation of Uruguay are referred to the basal stereospondyl taxon Mastodonsauridae. These represent the earliest known members of this group for South America. In most cases, this assignment was based on the characteristic morphology of the postglenoid (= postarticular) area of the lower jaw together with the presence of a hamate process. Comparisons with basal masto−donsaurids indicate that the Uruguayan specimens are phenetically similar to Gondwanan and Laurasian Early Triassic taxa, such as Watsonisuchus, Wetlugasarus, and Parotosuchus. Nevertherless, they display some characters which have not previously been described in Mesozoic temnospondyls. The Permo−Triassic Uruguayan mastodonsaurids support a Gondwanan origin for the group, an event which probably occurred sometime during the latest Permian.