Ancient South American carnivorous marsupial relatives, new research


This video says about itself:

30 Decamber 2017

Thylacosmilus is an extinct genus of saber-toothed metatherian that inhabited South America from the Late Miocene to Pliocene epochs.

Though Thylacosmilus is one of several predatory mammal genera typically called “saber-toothed cats“, it was not a felid placentalian, but a sparassodont, a group closely related to marsupials, and only superficially resembled other saber-toothed mammals due to convergent evolution.

Remains of this animal have been found primarily in Catamarca, Entre Ríos, and La Pampa Provinces in northern Argentina.

Thylacosmilus was described and named by Elmer S. Riggs in 1933. He named two species, T. atrox and T. lentis.

Thylacosmilus had large, saber-like canines. The roots of these canines grew throughout the animal’s life, growing in an arc up the maxilla and above the orbits. Its cervical vertebrae were very strong and to some extent resembled the vertebrae of Machairodontinae.

Body mass estimates of Thylacosmilus suggest this animal weighed between 80 to 120 kilograms (180 to 260 lb), and one estimate suggesting up to 150 kg (330 lb), about the same size as a modern jaguar.

From Proceedings of the Royal Society B:

Diversity and disparity of sparassodonts (Metatheria) reveal non-analogue nature of ancient South American mammalian carnivore guilds

3 January 2018

Abstract

This study investigates whether terrestrial mammalian carnivore guilds of ancient South America, which developed in relative isolation, were similar to those of other continents.

We do so through analyses of clade diversification, ecomorphology and guild structure in the Sparassodonta, metatherians that were the predominant mammalian carnivores of pre-Pleistocene South America. Body mass and 16 characters of the dentition are used to quantify morphological diversity (disparity) in sparassodonts and to compare them to extant marsupial and placental carnivores and extinct North American carnivoramorphans.

We also compare trophic diversity of the Early Miocene terrestrial carnivore guild of Santa Cruz, Argentina to that of 14 modern and fossil guilds from other continents.

We find that sparassodonts had comparatively low ecomorphological disparity throughout their history and that South American carnivore palaeoguilds, as represented by that of Santa Cruz, Argentina, were unlike modern or fossil carnivore guilds of other continents in their lack of mesocarnivores and hypocarnivores. Our results add to a growing body of evidence highlighting non-analogue aspects of extinct South American mammals and illustrate the dramatic effects that historical contingency can have on the evolution of mammalian palaeocommunities.

2 thoughts on “Ancient South American carnivorous marsupial relatives, new research

  1. Pingback: HG Wells, Attenborough, Martians and Tasmanian genocide | Dear Kitty. Some blog

  2. Pingback: Prehistoric saber-tooth marsupial Thylacosmilus, new research | Dear Kitty. Some blog

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