|Daughter taxa: (blue => in age window 0-800Ma)||Granddaughter taxa|
Test in a low to flat trochospiral, umbilicate, four to five petaloid chambers per whorl, sutures curved and oblique, depressed to thickened and nodose on the spiral side, depressed and radial around the small umbilicus on the umbilical side, periphery angular to truncate, bicarinate, the two variously spaced keels bordering an imperforate carinal band, keel on the umbilical side may be reduced to a row of short transverse costellae; wall calcareous, perforate, surface with pustules and short costellae in concentric alignment on the spiral side and radial on the umbilical side; primary aperture in teriomarginal, extraumbilical-umbilical, and with a porticus, portici of successive chambers coalescing in the early stage, larger in the adult stage and joined only at a few points to form a tegilla having distal accessory apertures.
Test trochospiral, with strongly convex spiral side, early chambers globular, later broad, low, and semilunate, with an undulating surface as seen from the spiral side, ovate from the umbilical side, sutures oblique, curved, thickened, elevated, and nodose on the spiral side, radial and depressed around the broad umbilicus that occupies up to one-half the test diameter on the flat to concave umbilical side, peripheral outline entire to lobulate, periphery with two very closely spaced keels separated by narrow imperforate carinal band and may be reduced to a single keel in the final few chambers; wall calcareous, finely perforate, radial, surface smooth between the elevated and nodose sutures and keel of the spiral side, finely pustulose on the umbilical side; aperture interiomarginal and umbilical, portici of successive apertures protruding obliquely into the umbilicus, with a distal accessory aperture beneath each porticus.
Test in a low to flat trochospiral coil, spiral side flat, umbilical side convex with wide umbilicus that is occupied by portici and tegilla, early chambers globular, later ones rhomboidal in section, sutures strongly curved, elevated and oblique on the spiral side, radial and depressed on the umbilical side, distinct peripheral keel on the edge of the spiral side, the umbilical peripheral margin with a less developed second keel consisting only of a row of pustules or this may be absent, peripheral outline entire to weakly lobulate; wall calcareous, perforate, surface pustulose, particularly on the umbilical side of the test; primary aperture interiomarginal, umbilical, and bordered by a wide porticus, those of successive chambers remaining as accessory apertures, and portici may fuse into tegilla in the later stage.
Test high to low trochospiral, umbilicus occupying from one-fourth to one-half the diameter of the flat to concave umbilical side, peripheral margin truncate and bicarinate, keels separated by an imperforate carinal band, keel on the umbilical side less well developed and may be absent from the final few chambers, peripheral outline entire to lobulate; wall calcareous, finely perforate, surface generally smooth on the spiral side, may be pustulose on the umbilical side, particularly on the earlier chambers, sutures curved to straight, elevated on the spiral side and depressed, flush, or elevated on the umbilical side; primary aperture interiomarginal and umbilical, may be bordered by portici in the early stage, later or always with a system of tegilla that cover most of the umbilicus and have both proximal and distal accessory apertures.
Test a low trochospiral, planoconvex to concavoconvex, compressed, chambers petaloid, about five in the final whorl, sutures radial, depressed, umbilicus of narrow to medium size, periphery acutely angled, with nonperforate carinal band or true keel, peripheral outline lobulate; wall calcareous, perforate, with pustulose suface and peripheral keel; primary aperture interiomarginal, extraumbilical-umbilical, in early chambers provided with a small triangular porticus, later with a distinct tegillum crossing the umbilicus, and with accessory apertures around the margins.
Test trochospiral, biconvex, chambers rhomboidal in section, sutures elevated, oblique or radial, straight or curved on the spiral side, depressed or elevated on the umbilical side, periphery with a beaded single keel that is continuous with the sutures on the spiral side, peripheral outline subcircular, polygonal, or lobate; wall calcareous, finely perforate, smooth except for the beaded sutures and peripheral keel and a concentric row of pustules near the umbilicus on the umbilical side; primary aperture interiomarginal, umbilical to slightly extraumbilical, successive apertures covered by portici that may remain free or may coalesce in the umbilicus to leave proximal accessory apertures.
Test trochospiral, biconvex to planoconvex, sutures sigmoidal, especially on the umbilical side, curved, elevated and may be beaded on the spiral side, imperforate carinal band between the two peripheral keels, peripheral outline entire to lobulate; wall calcareous, perforate, surface smooth to pustulose; primary aperture interiomarginal and extraumbilical-umbilical, bordered by a triangular porticus, those of successive apertures fusing and may even form true tegilla, infralaminal and occasionally intralaminal accessory apertures present.
Test trochospiral, planocovex with flattened spiral side and strongly convex umbilical side, chambers rhomboidal in section, the five to seven chambers of the final whorl each with a tubulospine at the proximal end of the chamber and in the plane of the spiral surface, less frequently a tubulospine may arise at the junction of two adjacent chambers, tubulospines increasing in size and length by lamellar growth, so that earlier ones of the final whorl may be larger than the later ones, umbilicus wide, up to one-half the test diameter, sutures radial to curved, depressed to slightly elevated and may be nodose, periphery with a single keel, peripheral outline polygonal; wall calcareous, densely perforate, surface smooth or with pustules covering the surface of early whorls and present along the sutures and peripheral keel; primary aperture umbilical, bordered by a large flat porticus, those of successive chambers imbricated within the umbilicus and may partially fuse.
Entries in the Catalog of original descriptions: Globotruncanidae
Distinguishing features: Test trochospiral, chambers angular, periphery truncate or carinate; primary aperture umbilical, covered by a spiral system of tegilla that is provided with accessory intralaminal and infralaminal apertures.
Last occurrence (top): within Maastrichtian Stage (66.04-72.05Ma, top in Maastrichtian stage). Data source: Total of range of species in this database
First occurrence (base): within Aptian Stage (112.95-126.30Ma, base in Aptian stage). Data source: Total of range of species in this database
Plot of range and occurrence data:
Brotzen, F. (1942). Die Foraminiferengattung Gavelinella nov. gen. und die Systematik der Rotaliiformes. Sveriges Geologiska Undersökning, Series C. 36(8): 1-60. gs Loeblich, A. R. & Tappan, H. (1988). Foraminiferal Genera and Their Classification (Volume I-II). Van Nostrand Reinhold Co., New York. 1-1059. gs
Brotzen, F. (1942). Die Foraminiferengattung Gavelinella nov. gen. und die Systematik der Rotaliiformes. Sveriges Geologiska Undersökning, Series C. 36(8): 1-60. gs
Loeblich, A. R. & Tappan, H. (1988). Foraminiferal Genera and Their Classification (Volume I-II). Van Nostrand Reinhold Co., New York. 1-1059. gs
Globotruncanidae compiled by the pforams@mikrotax project team viewed: 5-12-2020
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