Globivalvulina, Schubert, 1921

Vachard, D, Krainer, K & Lucas, SG, 2015, Late Early Permian (late Leonardian; Kungurian) algae, microproblematica, and smaller foraminifers from the Yeso Group and San Andres Formation (New Mexico; USA), Palaeontologia Electronica (English ed.) 3 (8), pp. 1-77 : 28-30

Genus GLOBIVALVULINA Schubert, 1921

Type Species. Valvulina bulloides Brady, 1876 .

Description. Test planispirally and biserially coiled; occasionally initially trochospiral. Coiling entirely involute, rarely semi-involute to evolute. Test subspherical to nautiloid, rarely ovoid. The ventral side is flattened to concave; the dorsal side is strongly convex to slightly curved. Proloculus spherical, more or less large and more or less inserted in the inner whorls. Few whorls (1-3) and relatively few chambers (6-10). Chambers inflated to triangular. Diameter small to medium, rarely large in Middle and Late Permian species (0.25- 1.00 mm). Septa complete and well-curved. Umbilicus slightly depressed to absent. A diversely developed oral valvula (or valvular projection) is present in the last chamber. Wall unilayered (microgranular or microgranular with a calcareous agglutinate) or bilayered (with a pseudofibrous inner layer discontinuously present). The described “diaphanotheca’’ seems only to correspond to a luminothecalike wall or even a diagenetic differentiation of the medium to thick microgranular walls. Aperture low, arched, central or peripheral at the extremity of a funnel diversely developed.

Remarks. For the phylogeny of this genus, see Vachard et al. (2006), Gaillot and Vachard (2007), and Cózar and Somerville (2012).

Although repetitively revised, the type species Globivalvulina bulloides remains under discussion, especially, its true aspects in transverse and axial sections. These types of section are perhaps more accurately known in G. moderata Reitlinger, 1949 , which has been synonymized with G. bulloides by Groves (1988) or Harris et al. (1997). Globivalvulina moderata sensu stricto differs by its smaller dimensions, and a microgranular wall that is never differentiated, but G. bulloides sensu Potievskaya, 1962 (p. 65-66, plate 4, figures 7, 8, 10, 11) is truly a G. ex gr. moderata . Geometrically, the best and most complete illustrations of G. bulloides have probably been provided by Kulagina et al. (1992, plate 4, figures 3, 4, 8; plate 8, figures 4, 5; plate 9, figure 28; plate 13, figures 23, 24, 25). Among the Pennsylvanian species of North America, G. gaptankensis Harlton, 1928 (p. 308-309, plate 53, figure. 3a-c) might be a synonym of G. bulloides , because G. bulloides , based on our collection materials can be described as follows: test subhemispherical (“similar to Globigerina ’’ according to the diagnosis of Brady, 1876) with a trochospirally coiled axis of biseriality; dorsal size moderately convex; round peripheral margin; lateral sides strongly convex to slightly compressed to the flanks; umbilicus absent; proloculus spherical medium-sized (0.04 mm); D = (0.17)- 0.30-0.50 mm; w = (0.19-0.21)-0.25-0.42-(0.47) mm; w/D = 0.96-1.17; 1.5 whorl; 4-7 (8) chambers at last whorl, very inflated, almost spherical, and with h = (0.07-0.09)-0.10-0.14-(0.20) mm; sutures curved, moderately deep; septa thin, typically globivalvulinid; ventral side flattened; aperture elongate, oblique, at the base and center of apertural face; oral valvula small in each chamber of last whorl or “heavy, strongly overlapping’’ ( Armstrong and Mamet, 1977); funnel short or absent; wall microgranular (eventually diagenetized with diaphanotheca-like median layer; Armstrong and Mamet, 1977; Brenckle et al., 1997); s = 0.01-0.02 mm.

Occurrence. Late Mississippian (Serpukhovian)- latest Permian (Changhsingian); cosmopolitan.