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

GOIN FJ; VIEYTES EC; CRESPO VD; OLIVEIRA EV

JOURNAL OF PALEONTOLOGY

PALEONTOLOGICAL SOC INC

Lugar: Lawrence; Año: 2023 p. 1 - 6

0022-3360

We discuss the affinities of Estelestes ensis (Mammalia, Metatheria). In our opinion, the Baja California taxon is not referable to the Didelphinae or to any other Didelphimorphia. On the contrary, we emphasize the affinities between Estelestes ensis and Bobbschaefferia fluminensis de Paula Couto, 1952 (de Paula Couto, 1952a), the latter from the early Eocene of Itaboraí in southeastern Brazil. The similarities with Bobbschaefferia are particularly interesting, as (1) this taxon was previously referred to a basal group of Polydolopimorphia (Marsupialia, Australidelphia; Oliveira and Goin, 2011); (2) several morphological matches are noticeable among Estelestes, Bobbschaefferia, and Glasbius (Glasbiidae), the latter two also previously considered to be basal groups of Polydolopimorphia (Goin et al., 2016; see a summary by Boyd et al., 2017 on the proposed affinities of Glasbius); and (3) Bobbschaefferia has been related to Tingamarra porterorum Godthelp et al., 1992, from the earliest Eocene of Murgon, Australia, and thus to the Australasian metatherian radiation (Woodburne and Case, 1996). If that is the case, Estelestes could also be related to this radiation.