Report of Ethusid Crabs (Brachyura, Ethusidae) from the Late Eocene of San Feliciano Hill (Monti Berici, Vicenza, NE Italy)

N. Jb. Geol. Paläont. Abh. 301/1 (2021), 17–23 Article Stuttgart, July 2021

Report of ethusid crabs (Brachyura, Ethusidae) from the late Eocene of San Feliciano hill (Monti Berici, Vicenza, NE Italy)

Antonio De Angeli and Alessandro Garassino With 4 ﬁgures

Abstract: The rich decapod assemblage from the late Eocene of San Feliciano hill (Orgiano, Vicen- za, NE Italy) was partially recorded by several authors. Herein, Ethusa orgianensis n. sp. and E. cf. E. berica De Angeli & Beschin, 2008 are reported thus expanding our knowledge of the Ethusidae Guinot, 1977 in the fossil record. Ethusa berica De Angeli & Beschin, 2008 has been recorded from the early Oligocene of Altavilla Vicentina (Vicenza) and from the late Eocene of Parona (Verona). The specimen reported from San Feliciano hill showing a different cardiac region is tentatively compared with that species.

Key words: Crustacea, Decapoda, Dorippoidea, Priabonian, taxonomy, Italy.

1. Introduction and geological setting stones including coralline algae and corals from the late Eocene (Priabonian), located in the San Feliciano Ethusa Roux, 1830, includes 44 extant species (Ng hill on the southern side of the hill (Fig. 2). The strati- et al. 2008; Castro 2013) widespread usually in shal- graphic unit is the so called “Formazione di Priabona” low environments. The rare fossil species for the ge- (late Eocene, Priabonian). The microfossil analysis by nus are restricted to the Cenozoic. Indeed, only five nannofossils provided by Beccaro (2003) confirmed species are known to date from the late Eocene (Pria the Priabonian age for all layers present in the quarry. bonian) to the early Pliocene of Italy, Hungary, and Ja- The lowest layers are represented by a well stratified pan (see fossil species in the systematic palaeontology greyish marly-limestone formation including many al- chapter). gae, nummulites, bivalves, several echinoderms, and The studied specimens, subject of this note, come rare decapod crustaceans [Palaeocarpilius macrochei from San Feliciano hill, located in Monti Berici (Or- lus (Desmarest, 1822)]. White- yellowish calcarenites, giano, Vicenza, NE Italy). Ethusa orgianensis n. sp. 6–7 meters thick, overlap the lower layers. These cal- improves the knowledge of the Ethusidae Guinot, carenites including coralline algae, corals, rare mol- 1977 in the fossil record, whereas one specimen is ten- lusc casts, and decapod crustaceans (De Angeli 2016; tatively compared with E. berica De Angeli & Be Quaggiotto & De Angeli 2019). Finally, the upper schin, 2008 due to the different shape of the cardiac part is represented by marly limestones including region. nummulites, bryozoans, bivalves, and echinoderms. San Feliciano hill is located on the southwestern side Many decapod crustaceans collected within the cal- of Monti Berici between Orgiano and Lonigo (Fig. 1). carenites were described by several authors (Fabiani The studied specimens are preserved within the lime- 1911; De Angeli & Garassino 2002, De Angeli &