Raninella armata Rathbun, 1935

Guinot, Danièle, Vega, Francisco J. & Van Bakel, Barry W. M., 2008, Cenomanocarcinidae n. fam., a new Cretaceous podotreme family (Crustacea, Decapoda, Brachyura, Raninoidia), with comments on related families, Geodiversitas 30 (4), pp. 681-719 : 681-719

Raninella armata Rathbun, 1935

Remarks

Only known by an abdomen from the Albian of the Western Interior ( USA), Raninella armata ( Rathbun, 1935: 50, pl. 11, figs 32, 33) was first recognised as a possible representative of Raninella A. Milne-Edwards, 1862 (type species R. trigeri A. Milne-Edwards, 1862 ) and later referred to as Cenomanocarcinus ( Stenzel 1945: 449; Bishop 1986: table 2; Schweitzer et al. 2003a: 36, 39). The abdomen, regarded as close to that of C. vanstraeleni by Stenzel (1945) and Larghi (2004: 534), differs by the conical median teeth on each abdominal segment rather than the three transverse ridges found on each abdominal segment in C. vanstraeleni ( Figs 3A, C ; 5A-C). On the other hand, the broad and long abdomen in R. armata , at least if it is a male abdomen, appears too developed to accompany a thoracic sternum such as that of R. trigeri (see Glaessner 1969: fig. 313.6b), a lyreidine according to Tucker (1998: 322, fig. 22). In the Lyreididae Guinot, 1993 the relatively short and narrow abdomen is maintained by a pair of strong projections from sternite 5 firmly fitting into a pair of sockets in the angles of abdominal segment 6 ( Guinot 1993: figs 4, 6, 7; Guinot &

Bouchard 1998: fig. 11; Feldmann & Schweitzer

Guinot D. et al.

2007: fig. 4). At present, despite some similarities in abdomen shape to C. vanstraeleni , we prefer to leave R. armata outside Cenomanocarcinus . The abdomen of R. armata could also represent that of a Notopocorystes .

Figures

FIG. 3. — A-D, F, Cenomanocarcinus vanstraeleni Stenzel, 1945; A, B, C, F, late Cenomanian-Turonian, Eagle Ford Group, Turonian, Múzquiz, Coahuila, Mexico; D, late Cenomanian, Eagle Ford Group, Britton Formation, California Crossing, Dallas County, Texas; E, Cenomanocarcinus sp., upper Albian,Colombia;A, female (MUZ-216),thoracic sternum (anterior portion of sternite 4 exposed) covered laterally by abdomen, mxp3, and pereiopods; at left, inflated P4 propodus (MUZ-212); B, mxp3 (MUZ-212); C, female (MUZ-201), sternite 4 with pair of tubercles, and abdomen;D,?female,paralectotype (BEG-21091-A1),thoracic sternum without abdomen; E, thoracic sternum (associated with carapace) showing a crown-shaped plate,long sternite 4, and deep, curved sutures 4/5 (INGEOMINAS/ Jur-1; Vega et al. in study); F, male (MUZ-215), thoracic sternum (see deep sutures 4/5) and abdomen. Scale bars: 10 mm.