Hostname: page-component-74656f9884-g96k6 Total loading time: 0 Render date: 2026-11-10T07:38:51.324Z Has data issue: false hasContentIssue false

†Estelestes ensis (Mammalia, Metatheria) from the early Eocene of Baja California (Mexico) as a generalized polydolopimorphian

Published online by Cambridge University Press:  16 January 2023

Francisco J. Goin*
Affiliation:
CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), Argentina División Paleontología Vertebrados, Facultad de Ciencias Naturales y Museo de La Plata, Universidad Nacional de La Plata. Paseo del Bosque s/n, B1900FWA La Plata, Argentina
Emma Carolina Vieytes
Affiliation:
CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), Argentina División Zoología Vertebrados, Facultad de Ciencias Naturales y Museo de La Plata, Universidad Nacional de La Plata, Paseo del Bosque s/n, B1900FWA La Plata, Argentina
Vicente D. Crespo
Affiliation:
Departamento de Ciências da Terra, FCT-UNL Faculdade de Ciências E Tecnologia, GeoBioTec, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
Édison V. Oliveira
Affiliation:
PPGEOC, Programa de Pós-Graduação em Geociências, and Paleolab, Laboratório de Paleontologia, Departamento de Geologia, Centro de Tecnologia e Geociências, Universidade Federal de Pernambuco, Av. Acadêmico Hélio Ramos, s/n, Cidade Universitária, 50740-530, Recife, PE, Brazil
*
*Corresponding author.

Extract

Estelestes ensis Novaceck et al., 1991 is a curious Paleogene metatherian mammal recognized on the basis of a single specimen from Baja California (Mexico) in southern North America. It comes from early Eocene (Wasatchian age) levels of the Las Tetas de Cabra Formation at “Marsupial Hill” in the Lomas Las Tetas de Cabra site (also known as Punta Prieta; see Novaceck et al., 1991). The specimen consists of a fragmentary left mandible with the last premolar, the roots of the first two molars, and almost complete last two molars (Fig. 1). It was referred to the Didelphini (Marsupialia, Didelphimorphia, Didelphidae, Didelphinae) even though Novaceck et al. (1991) stated that the overall morphology of the type specimen poses intriguing problems regarding its relationships. For example, the very deep, robust jaw of Estelestes distinguishes it from any other Holarctic “didelphine” (at the time Novaceck et al., 1991 published their work, both the concept and extent of Didelphidae and Didelphinae were much broader than today). Interestingly, they concluded that Estelestes had close affinities with “Mirandotherium” (lapsus calami for Mirandatherium), from the early Eocene of Itaboraí, in southeastern Brazil. “Resemblance between the two taxa is nevertheless striking, once again raising the possibility of close relationships among certain early members of the Northern Hemisphere and South American Didelphinae” (Novaceck et al., 1991, p. 16). The affinities of Mirandatherium are contested, having been regarded as part of the Didelphimorphia (e.g., de Paula Couto, 1952a) or Microbiotheria (e.g., Marshall, 1987; McKenna and Bell, 1997; Oliveira and Goin, 2011), or even as an alphadontian (Carneiro, 2019).

Information

Type
Taxonomic Note
Copyright
Copyright © The Author(s), 2023. Published by Cambridge University Press on behalf of The Paleontological Society
Figure 0

Figure 1. Estelestes ensis Novaceck et al., 1991. (1) Photographic stereopair of IGM 3688 (type) showing p3, roots of m1–2, and m3–4 in occlusal view. (2) IGM 3688 in labial view. (3) IGM 3688 in lingual view.

Figure 1

Figure 2. Map of the Americas, Antarctica, and Australia showing localities where glasbiids, or taxa related to Glasbiidae, come from. 1: Estelestes ensis, early Eocene, Mexico (Novaceck et al., 1991). 2: Glasbius spp., latest Cretaceous, various localities in North America (see Boyd et al., 2017 and literature cited). 3: Chulpasia mattaueri, late Paleocene–early Eocene of Perú (Sigé et al., 2009). 4: Mirandatherium alipioi and Bobbschaefferia fluminensis, early Eocene, southeastern Brazil (de Paula Couto, 1952a). 5: Reigia punae, ?middle Eocene, northwestern Argentina (Pascual, 1983). 6: Apeirodon sorianoi, late Eocene, northwestern Argentina (Babot et al., 2020). 7: Palangania brandmayri, early–middle Eocene, Patagonia (Goin et al., 1998). 8: Periakros ambiguus, early Oligocene, Patagonia (Goin et al., 2010). 9: Pujatodon ektopos, early–middle Eocene, Antarctic Peninsula (Goin et al., 2020). 10: Thylacotinga bartholomaii, early Eocene, Australia (Archer et al., 1993).

Figure 2

Figure 3. (1, 2) Labial view of dentaries: (1) Estelestes ensis; (2) Bobbschaefferia fluminensis. (3) Occlusal-labial view of the dentary of B. fluminensis indicating the alveoli for the incisors (i2–5) and canine (c).