Raninella oaheensis Van Bakel & Guinot & Artal & Fraaije & Jagt, 2012

Van Bakel, Barry W. M., Guinot, Danièle, Artal, Pedro, Fraaije, René H. B. & Jagt, John W. M., 2012, A revision of the Palaeocorystoidea and the phylogeny of raninoidian crabs (Crustacea, Decapoda, Brachyura, Podotremata) 3215, Zootaxa 3215 (1), pp. 1-216 : 81

Bournelyreidus ? oaheensis ( Bishop, 1978) n. comb.

Raninella oaheensis Bishop, 1978: 615 .

Material examined. A cast of the holotype ( GAB 36-101 ; Bishop 1985: fig. 3), is housed in MAB ( MAB k. 0217) .

Remarks. Raninella oaheensis (see Bishop 1978: 615, pl. 1, figs. 7–11, pl. 2, figs. 1–20) was originally recorded from the Pierre Shale (upper Campanian-lower Maastrichtian) of South Dakota and Montana, U.S.A. ( Bishop 1978: 615), but was subsequently recognised in North Dakota ( Tucker et al. 1987: 278, table 1), as well as in the Fox Hills Formation (Maastrichtian) of South Dakota ( Crawford et al. 2006). This species is here reassigned to Bournelyreidus n. gen. based on features of the carapace and thoracic sternum of which the anterior sternites are preserved in the type lot ( Bishop 1978: pl. 1, fig. 7; pl. 2, fig. 3).

The posterolateral margin is not well-preserved in the type series. It was shown as more or less straight in the line drawing by Bishop (1978: 611, text-fig. 5). Better-preserved specimens ( Tucker et al. 1987: fig. 6) clearly show the medial third of the carapace with vertical margins. The branchiocardiac grooves are well developed.

Of the thoracic sternum, only the anterior sternites are known ( Bishop 1978: pl. 1, fig. 7; pl. 2, fig. 3). Sternite 4 is wide anteriorly, long, lateral margins are concave and raised, episternite 4 is rather small. Only a small central portion of sternite 5 is preserved ( Bishop 1978: pl. 1, fig. 7); no medial line is present, which precludes assignment of the species to Raninella .

Several carapace characters distinguish B.? oaheensis from other members of the genus: the rostrum is narrower, non-bifid, with a subtle keel extending onto the carapace; the orbital margins are slightly directed outwards, rather than horizontal, with the fissures open rather than closed. The outer orbital corners, which normally are prominent in Bournelyreidus n. gen., appear to be weakly developed in the present species; however, this needs to be verified in the type series. Bournelyreidus ? oaheensis appears to have some characters in common with Heus , namely a narrow, sulcate and keeled rostum, and open orbital fissures. The narrow carapace with two anterolateral spines, absence of a cervical groove and of swellings on the anterior carapace, favour assignment of the present species for the time being to Bournelyreidus n.gen..