Monodaeus bortolottii Delle Cave, 1988: 123-126

Pasini, Giovanni, Garassino, Alessandro & Sami, Marco, 2019, Decapod assemblage from the late Miocene (early-middle Messinian) of the Romagna Apennines nearby Brisighella, Emilia-Romagna (N Italy), Natural History Sciences 6 (1), pp. 27-32 : 30

Monodaeus bortolottii Delle Cave, 1988: 123-126 , Pl. 1, figs. 1, 2, Pl. 2, figs. 1-5.

Monodaeus bortolottii – De Angeli & Garassino 2006: 74. — De Angeli et al. 2009: 185, 195, fig. 16. — Schweitzer et al. 2010: 126. — Garassino et al. 2012: 52. — Baldanza et al. 2013: 347, 348, fig. 13. — Pasini & Garassino 2013a: 325, 326, fig. 5. — Pasini & Garassino 2013b: 344, 345, fig. 2. — Pasini et al. 2014: 254, 255, fig. 9B. — Baldanza et al. 2017: 60, 61, fig. 15C. — Pasini et al. 2018: 31 , fig. 3A.

Material and measurements: 13 carapaces in dorsal view ( MSF 2300 – lcxp: 18 mm, wcxp: 26 mm); MSF 2307 – lcxp: 16 mm, wcxp: 22 mm; MSF 1154 – lcxp: 20 mm, wcxp: 28 mm; MSF 2309 – lcxp: 13 mm, wcxp: 18 mm; MSF 2315 – lcxp: 10 mm, wcxp: 14 mm; MSF 2318 – lcxp: 6 mm, wcxp: 9 mm; MSF 2325 – lcxp: 10 mm, wcxp: 13 mm; MSF 2326 – lcxp: 9 mm, wcxp: 12 mm; MSF 2327 – lcxp: 17 mm, wcxp: 24 mm; MSF 2328 – lcxp: 12 mm, wcxp: 14 mm; MSF 2329 – lcxp: 13 mm, wcxp: 15 mm; MSF 2330 – lcxp: 7 mm, wcxp: 9 mm; MSF 2331 – lcxp: 6 mm, wcxp: 8 mm).

Discussion. The studied specimens have been assigned to Monodaeus bortolottii Delle Cave, 1988 in having a slightly convex suboctagonal carapace, wider than long; straight front margin, with a weak median incision; short convex anterolateral margin; long convergent posterolateral margin; posterior margin straight medially; dorsal region well marked by grooves, with wide raised epigastric lobes; well-marked suboval protogastric regions; subpentagonal mesogastric regions with narrow, elongate anterior process between protogastric regions; cardiac region well marked by branchiocardiac grooves; small poorly marked hepatic regions; and wide, well-marked, branchial regions.

Monodaeus bortolottii has been previously reported from the Pliocene of Volterra (Delle Cave, 1988) and Grosseto (De Angeli et al., 2009). Later Pasini & Garassino (2013a, b) and Garassino, Hyžný & Pasini in Baldanza et al. (2013) reported this species from the Pliocene (Piacenzian) of Castellarano and Monticelli di Quattro Castella (Reggio Emilia, Emilia-Romagna), from the early Pliocene of Cassine (Alessandria, Piedmont), and from the early Pleistocene of the Poggio i Sodi (Siena, Tuscany). Later Pasini et al. (2014) reported M. bortolottii from the early Pleistocene of Volterra (Pisa, Tuscany), close to the type locality originally reported by Delle Cave (1988). Recently this species has been reported also from the early Pleistocene of Poggi Gialli (Sinalunga, Tuscany) by De Angeli, Garassino & Pasini in Baldanza et al. (2017), and from the Pliocene of Faenza (Ravenna, Emilia-Romagna) ( Pasini et al., 2018). This is the first record of this species in the Miocene, notably enlarging its stratigraphic range.