Contributions to Zoology, 72 (2/3) (2003)Alessandro Garassino; Antonio De Angeli: Munida casadioi (Schweitzer & Feldmann, 2000) from the Eocene of the Bariloche area, Patagonia (Argentina)

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Introduction

Schweitzer & Feldmann (2000) erected the new genus Austromunida (type species: A. casadioi) on the basis of three more or less complete specimens (holotype: GHUNLPam 16832; paratypes: GHUNL-Pam 16833, 16834; Geological Museum, Universidad nacional de La Plata) from the middle Eocene Centinela Formation on Estancia 25 de Mayo, Calafate, Santa Cruz (Argentina). Although the authors did note the superficial similarity to Munida Leach, 1820, they justified the erection of the new genus on features not present in all other known fossil galatheids, e.g., the narrow, needle-like rostrum, transverse ridges and numerous lateral spines.

However, the recent discovery of a rich assemblage of galatheids in the Bariloche area (Dipartimento di Paleontologia degli Invertebrati, Museo civico di Storia naturale di Milano, work in progress), casts doubts over the validity of the genus Austromunida. Some of these specimens show the needle-like rostrum, identical to the ones seen in material from Calafate, and as a consequence this feature might be used to refer these specimens to Austromunida. However, two individuals have well-developed supraorbital spines. These are not present in A. casadioi, but this may be a preservational matter: the frontal region of the carapace is poorly preserved, which might give the impression of their absence (see also Schweitzer & Feldmann, 2000, fig. 4).