Body mass estimation in Early Miocene native South American ungulates: A predictive equation based on 3D landmarks

Authors
Cassini, Guillermo Hernán; Vizcaíno, Sergio Fabián; Bargo, María Susana
Publication Year
2012
Language
English
Format
article
Status
Published version
Description
South American native ungulates include extinct taxa that evolved within the geographical context given by the isolation of South America during most of the Cenozoic. The ungulates (orders Notoungulata, Litopterna and Astrapotheria) of the Santa Cruz Formation (late Early Miocene) are particularly interesting for paleobiological studies due to their diversity, richness and quality of preservation of the specimens. The body mass estimation of extinct species is one of the basic biological attributes for paleobiological reconstructions. The most common way to estimate body mass from fossils is using linear regression. Here, we used geometric morphometric techniques in order to estimate their body mass. We used regressions based on centroid size of 3D craniomandibular landmark configurations, including extant ungulates (their size and ecological relatives). Cases were weighted to maximize the taxonomic evenness. A broad body size range was recorded. The highest predictive power is obtained with those functions derived from the highest taxonomic and ecological diversity. The highest taxonomic richness corresponds to masses below 100kg. Among Notoungulata, typotheres (Hegetotheriidae + Interatheriidae) vary from 1 to less than 10kg, while the smaller toxodontid reached 100kg and the larger 500kg. Litoptern proterotheriid body masses vary from 10 to 50kg, and macraucheniids surpass 100kg. The astrapotheres (Astrapotheria) reached (or even surpassed) 1000kg, being the only megamammal in the Santacrucian ungulate assemblage.
Fil: Cassini, Guillermo Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; Argentina
Fil: Vizcaíno, Sergio Fabián. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina
Fil: Bargo, María Susana. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina
Subject
ASTRAPOTHERIA
BODY MASS
CENTROID SIZE
LITOPTERNA
MIOCENE
NOTOUNGULATA
PATAGONIA
SANTACRUCIAN
Zoología, Ornitología, Entomología, Etología
Ciencias Biológicas
CIENCIAS NATURALES Y EXACTAS
Paleontología
Ciencias de la Tierra y relacionadas con el Medio Ambiente
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/68064