INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
The structure of the mammalian predator guild in the Santa Cruz Formation (late early Miocene).
ERCOLI, M.; PREVOSTI, F.J.; FORASIEPI, A.M.
JOURNAL OF MAMMALIAN EVOLUTION
Lugar: Berlin; Año: 2014 vol. 21 p. 369 - 369
The Santa Cruz Formation (late early Miocene,Santacrucian age) registers 11 species of mammalian predators(Metatheria, Sparassodonta). Together with large carnivorousflightless birds, they comprised the terrestrial predatorguild. The Santacrucian sparassodonts were diverse in bodysize, had different locomotory habits, and were primarilyhypercarnivores. The objective of this work is to analyze theguild structure of the sparassodonts of the Santa Cruz Formation,using the variables of body mass, diet, and locomotion asproxies. Furthermore, we analyze the interaction with otherpredators and potential prey. The univariated test V of Pooleand Rathcke and the multivariated test of Clark-Evans wereused to construct the models. In the multivariate test, wemade aPrincipal Component Analysis to resume and standardize thevariables. With body mass and locomotion we obtained anevenly spaced pattern of segregation for the sparassodont species,being non-significant and significant, respectively. Thepattern was aggregated and significant only with diet. Theanalysis of all variables together resulted in an evenly spacedand significant pattern, which is consistent with characterdisplacements (segregation of species throughout themorphospace) that would help to diminish interspecific competitionduring the Santacrucian age and would allow selectionof prey species of different sizes and substrate specializations.When the body size pattern of predator birds and sparassodontswere plotted together, the pattern is evenly spaced and nonsignificant.Other factors, including locomotion, would differentiatethese species and their ecological niches.