Los Metatheria Sudamericanos de Comienzos Del Neógeno (Mioceno Temprano, Edad MamÍFero Colhuehuapense): Microbiotheria y Polydolopimorphia

Abstract

Resumen. En este trabajo se encara la revisión sistemática de dos órdenes de Metatheria (Mammalia) sudamericanos de la Edad Colhuehuapense (Mioceno temprano): Microbiotheria y Polydolopimorphia. En primer lugar, se comentan y discuten las homologías de las cúspides de los molares superiores e inferiores de los Argyrolagoidea (Polydolopimorphia). En segundo lugar, se ofrecen los resultados de un análisis filogenético de los Microbiotheriidae (Microbiotheria). En tercer lugar, se analizan los taxones colhuehuapenses de Microbiotheria y Polydolopimorphia, reconociéndose dos especies nuevas:

A Late Miocene Argyrolagidae (Mammalia, Metatheria, Bonapartheriiformes) from Northwestern Argentina

“…The terminology used here is the usual in recent works carried out on the Argyrolagidae (e.g., Zimicz, 2011;Goin and Abello, 2013) with the addition of some terms for practical purposes, such as mesiolabial lobe (StA + epiconular shelf) equivalent to the anterobuccal lobe or projection of Simpson (1970a). Although this nomenclature usually refers to molar cusps (i.e., protocone, paracone, metacone, etc.…”

Comparative histology of the digestive tract in three new world marsupials

“…Contrary to an extended perception, living New World marsupials (Mammalia, Metatheria) are not "living fossils" (Goin, 2003). The Didelphidae, (Order Didelphimorphia), which constitute the most diverse group of living opossums (the remaining ones being the Microbiotheria and the Paucituberculata), have their oldest undoubted record in the early Miocene of Patagonia, ca.…”

“…The Didelphidae, (Order Didelphimorphia), which constitute the most diverse group of living opossums (the remaining ones being the Microbiotheria and the Paucituberculata), have their oldest undoubted record in the early Miocene of Patagonia, ca. 20 million years before present (Goin et al, 2007). Notwithstanding, the more generalized peradectoid didelphimorphians are much older, with their oldest record extending far down to the Late Cretaceous of North America (Williamson, Brusatte, Carr, Weil, & Standhardt, 2012) and the early Palaeocene (ca.…”

A new species of small-bodied sparassodont (Mammalia, Metatheria) from the middle Miocene locality of Quebrada Honda, Bolivia

“…Among sparassodonts, the Miocene records the first appearance of true borhyaenids and the highly specialized, saber-toothed thylacosmilids (Marshall, 1978;Goin et al, 2007;. Much of the Miocene sparassodont fossil record is based on early Miocene fossils from southern Patagonia (Colhuehuapian and Santacrucian SALMAs) and late Miocene fossils from northern Argentina (Huayquerian SALMA).…”