INVESTIGADORES
PREVOSTI Francisco Juan
artículos
Título:
ESTIMACIÓN DE MASA DE LAS ESPECIES DE SPARASSODONTA (MAMMALIA, METATHERIA) DE LA EDAD SANTACRUCENSE (MIOCENO TEMPRANO) A PARTIR DEL TAMAÑO DEL CENTROIDE DE LOS ELEMENTOS APENDICULARES: INFERENCIAS PALEOECOLÓGICAS
Autor/es:
ERCOLI, M. D.; PREVOSTI, F. J.
Revista:
AMEGHINIANA
Editorial:
ASOCIACION PALEONTOLOGICA ARGENTINA
Referencias:
Año: 2012 vol. 48 p. 462 - 479
ISSN:
0002-7014
Resumen:
Sparassodonts have been described as a group with a large body-mass diversity, but few works had focused on the body mass estimations. In this contribution, we calculated the centroid size of the anterior view of the distal humerus, lateral view of the proximal ulna, and proximal articular view of the tibia. These data together with the known body-mass for many current predators (marsupials and placentals) allowed to obtain new allometric equations to estimate body size in extinct mammalian carnivores (i.e., Sparassodonta). Using comparative analyses, we quantified the effect of the phylogenetic structure over the equations. The relationship between body mass, centroid size, and locomotory habits was explored. The phylogenetic effect was significant for all regressions. In the humerus analysis, we found an important relationship between body mass and locomotory habit, suggesting adaptive causes for this pattern. We used the ulna and tibia regressions to predict body mass, since they were less influenced by locomotory habits. We obtained the following masses: Arctodictis sinclari Marshall, 39.9 kg; Borhyaena tuberata Ameghino, 36.4 kg; Cladosictis patagonica Ameghino, 6.6 kg; Lycopsis longirostrus Marshall, 29.77 kg; Prothylacynus patagonicus Ameghino, 31.79 kg; Sipalocyon gracilis Ameghino, 2.11 kg; and Thylacosmilus atrox Riggs, 117.36 kg. For Borhyaena and Thylacosmilus, we obtained numbers higher than previously published masses, while for Pseudonotictis pusillus Ameghino, we made the first body mass estimation: 1.17 kg. The results suggest that the guild of the santacrucian predators was structured by the body mass, but other niche variables, such as diet and locomotion, were also relevant factors.
