Cenomanocarcinus Van Straelen, 1936

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

Genus Cenomanocarcinus Van Straelen, 1936

Cenomanocarcinus Van Straelen, 1936: 37 . — Stenzel 1945: 447; 1952: 214. — Remy & Avnimelech 1955: 314. — Remy 1960: 57, 63. — Avnimelech 1961: 1. — Förster 1968: 175, 188, 190. — Glaessner 1969: R494. — Wright & Collins 1972: 62. — Feldmann et al. 1976: 985, 988. — Kues 1980: 862. — Bishop 1986: 135, table 2. — Bishop & Williams 1991: 452. — Bishop et al. 1992: 419. — Feldmann 1993: 208. — Fraaije 2002: 913, 914. — Larghi 2004: 530, 534, 535. — Schweitzer & Feldmann 2000: 241, 246 (key), fig. 1, table 1; 2005: tables 4, 5, 7. — Schweitzer et al. 2002: 37, fig. 29, table 4; 2003a: 36. — Crawford et al. 2006: 5. — Breton & Collins 2007: 18. — Vega et al. 2007: 412.

Necrocarcinus (Cenomanocarcinus) – Bishop 1985: 618,

621. — Toolson & Kues 1996: 114, 115.

Cenomanocarcinidae n. fam. ( Crustacea, Decapoda ) from Cretaceous

TYPE SPECIES. — Cenomanocarcinus inflatus Van Straelen, 1936 by original designation.

SPECIES INCLUDED. — Cenomanocarcinus beardi Schweitzer, Feldmann, Fam, Hessin, Hetrick, Nyborg & Ross, 2003 ; Hasaracancer cristatus Jux, 1971 ; Necrocarcinus oklahomensis Rathbun 1935 ; C. vanstraeleni Stenzel, 1945 .

STRATIGRAPHIC RANGE. — Upper Albian ( Colombia), Cenomanian and Turonian ( France, Germany, Texas, North Dakota, Mexico and Colombia) to Coniacian- Santonian (British Columbia, Canada). In the Tethyan Province.

Remarks

Cenomanocarcinus was considered invalid by Stenzel (1945: 447) and renamed “ Cenomanocarcinus Van Straelen, 1936 in Stenzel 1945 ” ( Stenzel 1952: 214), but Förster (1968: 175) correctly re-assigned it to Van Straelen, 1936. First included in the Calappidae De Haan, 1833 ( Van Straelen 1936; Stenzel 1945, 1952; Feldmann 1993), it was transferred, as a valid genus, to the Necrocarcininae Förster, 1968 ( Förster 1968: 175). Subsequently, Cenomanocarcinus was synonymised with Necrocarcinus Bell, 1863 (eventually with Orithopsis Carter, 1872 ) ( Wright & Collins 1972: 62; Feldmann et al. 1976: 986; Kues 1980: 862; Fraaije 2002: 913), or, alternatively, considered a subgenus of Necrocarcinus ( Bishop 1985: 618, 621; Toolson & Kues 1996: 114, 115). It was finally rehabilitated as a member of the Necrocarcinidae ( Bishop & Williams 1991: 452; Schweitzer et al. 2002: table 8, fig. 29; Schweitzer et al. 2003a: 36; Schweitzer & Feldmann 2005: 34). By removing the Necrocarcinidae (including Cenomanocarcinus ) from the Calappoidea De Haan, 1833 to refer it to the Dorippoidea MacLeay, 1838, Schweitzer et al. (2003a: 32) considered Cenomanocarcinus to be a heterotreme representative.

In contrast, the hypothesis that Cenomanocarcinus could be podotreme was put forward by Larghi (2004: 530) and Guinot & Breton (2006: 616). Vega et al. (2007: 412) included the genus in the Podotremata. Breton & Collins (2007: 17) have recently documented the type species, C. inflatus , well on the basis of a near-complete topotypical specimen.The carapace outline of Cenomanocarcinus , traditionally based on specimens with broken spines,

is not rounded as assumed, its anterolateral border

Guinot D. et al.

prolonginginto a well-developed epibranchial tooth. A long and more or less thick epibranchial tooth, similar to that described for C. beardi ( Schweitzer et al. 2003a: fig. 12), is a diagnostic feature of the genus.

Cenomanocarcinus , a “carinate genus” ( Bishop & Williams 1991), is characterized dorsally by the following features: extremely thin carapace cuticle, dorsal carapace surface without marked grooves and with three strong, tuberculate longitudinal ridges (H-shape) and a tuberculate epibranchial ridge ending in a long epibranchial tooth; presence of a subdistal posterolateral tooth (see diagnosis of Cenomanocarcinidae n. fam. and under C. vanstraeleni ). According to Vega et al. (2007) the flattened appendages (of C. vanstraeleni ) suggest a burrowing (in point of fact, burying) habit and/ or active swimming.