Fossil crabs (Crustacea: Decapoda) from the Late Cretaceous cárdenas Formation, east-central Mexico

Abstract

Twenty-four nearly complete carapace samples were collected at three different localities of the Maastrichtian (Late Cretaceous) Cárdenas Formation in San Luis Potosí, east-central Mexico. The material has been assigned to five families: the Callianassidae, Dakoticancridae, Carcineretidae, ?Majidae, and Retroplumidae. Two genera of callianassid shrimp are described, Cheramus for the first time in the fossil record. Dakoticancer australis Rathbun is reported as the most abundant crustacean element; one new genus and species of carcineretid crab, Branchiocarcinus cornatus, is erected, and a single, fragmentary specimen is questionably referred to the Majidae. The three localities reflect paleoenvironmental differences, exhibited by different lithologies, within marginal marine, lagoon environments. The record of dakoticancrid crabs in the Cardenas Formation extends the paleobiogeographic range of the family and the genus Dakoticancer. Carcineretid crabs, although not abundant, seem to have been a persistent element of crustacean assemblages in clastic environments during the Late Cretaceous of the ancestral Gulf Coast of Mexico.

Cenomanian–Coniacian (Upper Cretaceous) bivalves of the Sergipe Basin, Brazil: Order Pholadomyida

“…In addition, Ph. gigantea is recorded from a lower stratigraphic level, viz., Tithonian?-Valanginian to upper Aptian (Dhondt & Dieni, 1988;Lazo, 2007 (Morton, 1833;Weller, 1907;Richards, 1958;Pickett, 1972;Sohl & Koch, 1984), Tennessee (Wade, 1926), and Mexico (Vega et al, 1995). Postero-dorsal margin slightly concave to straight.…”

First described species of Costacopluma (Crustacea: Brachyura: Retroplumidae) from the Pacific slope, Paleocene of California, USA

“…The youngest representative is C. grayi from the Eocene of Alabama (Feldmann and Portell, 2007). During the Late Cretaceous (Campanian-Maastrichtian), Costacopluma was distributed in western Africa and north of India (Collins and Morris, 1974;Gaetani et al, 1983), northern Mexico (Vega and Perrilliat, 1989;Vega et al, 1995), southeastern United States (A. Armstrong, pers.…”

First evidence of the Cretaceous decapod crustacean Protocallianassa from Sweden

“…Protocallianassa is common in younger deposits at a few locations including the USA (Roberts 1962), Argentina , Chile (Förster & Stinnesbeck 1987) and Antarctica (Feldmann & Wilson 1988). Campanian Protocallianassa have been described previously from Germany (Mertin 1941;Mourik et al 2005), the USA (Roberts 1962;Bishop 1985) and from Mexico (Vega et al 1995). Other Cretaceous occurrences include the Maastrichtian of The Netherlands and Belgium (Swen et al 2001), the USA (Roberts 1962), Mexico (Vega et al 1995) and Chile (Förster & Stinnesbeck 1987).…”

“…Campanian Protocallianassa have been described previously from Germany (Mertin 1941;Mourik et al 2005), the USA (Roberts 1962;Bishop 1985) and from Mexico (Vega et al 1995). Other Cretaceous occurrences include the Maastrichtian of The Netherlands and Belgium (Swen et al 2001), the USA (Roberts 1962), Mexico (Vega et al 1995) and Chile (Förster & Stinnesbeck 1987). Early Cretaceous (AptianBarremian) occurrences are represented only in the southern hemisphere: Argentina (Aguirre-Urreta 1983) and Antarctica (Taylor 1979).…”

“…Pereiopod measurements (mm) were made according to Swen et al (2001): maximum, (mean) and minimum dimensions are listed in Tables 1 and 2: propodus length: 37, (28.5) and 23 based on 12 specimens; manus length: 28, (21) Protocallianassa faujasi specimens ( Fig. 6; Table 2) closely approximate other examples of this species (Vega et al 1995;Swen et al 2001;Mourik et al 2005).…”