Subbotinatrivialis (Subbotina).—Huber, 1991c:461, pl. 3: figs. 16, 17 [Zone API, ODP Hole 738C/I7R: 350.45 mbsf; Kerguelen Plateau, southern Indian Ocean],—Olsson, Hemleben, Berggren, and Liu, 1992:202, pl. 4: figs. 5-8 [Zone Pla, Pine Barren Mbr., Clayton Fm., Millers Ferry, Alabama]. [Olsson et al. 1999]
Taxonomic discussion: Although Subbotina's original description refers to 4-4½ chambers in the final whorl, her illustrations of the holotype and paratypes show only 3½ chambers. Blow (1979) presented a thorough analysis of this morphospecies with which we in large part agree. Like Blow, we have not observed individuals as large as 0.4 mm in diameter as noted by Subbotina (1953) for her holotype from the northern Caucasus. In fact, remeasurement of her holotype (Plate 9: Figures 10-12) shows a diameter of 0.35 mm. Blow (1979) also described forms with more closely appressed chambersand abortively developed final chambers (as Eoglobigerina cf. trivialis) and forms with a turreted, high-spired umbilical side (as Eoglobigerina aff. trivialis). We include these morphotypes here in the concept of trivialis, as they do not appear to have any significant numerical representation or stratigraphic continuity in occurrence. [Olsson et al. 1999]
Distinguishing features: Parent taxon (Subbotina): Low trochospiral, tripartite test, with 3-4 rapidly inflating, globular chambers in final whorl.
Umbilicus nearly closed by tight coiling.
Wall cancellate with spines at nodes of the ridges, +/- spine collars. This taxon: Test small (<250µm) low trochospiral, tightly coiled with 3½ chambers in final whorl Aperture umbilical with a thin lip. The ultimate chamber is equal to, or slightly smaller than the penultimate one. The wall is weakly cancellate and spinose. The spines are set at the junctures of the cancellate ridges. The umbilicus is small and nearly closed by the tight coiling.
NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus. They are being edited as the site is developed and comments on them are especially welcome.
Description
Diagnostic characters: A low trochospiral, tightly coiled test with 3½ chambers in the ultimate whorl and an umbilical aperture with a thin lip. The ultimate chamber is equal to, or slightly smaller than the penultimate one. The wall is weakly cancellate and spinose. The spines are set at the junctures of the cancellate ridges. The umbilicus is small and nearly closed by the tight coiling. The overall size of the test is generally less than 250 um. [Olsson et al. 1999]
Character matrix
test outline:
Lobate
chamber arrangement:
Trochospiral
edge view:
Equally biconvex
aperture:
Umbilical
sp chamber shape:
Inflated
coiling axis:
Low
periphery:
N/A
aperture border:
Thin lip
umb chbr shape:
Inflated
umbilicus:
Narrow
periph margin shape:
Broadly rounded
accessory apertures:
None
spiral sutures:
Strongly depressed
umb depth:
Deep
wall texture:
Cancellate
shell porosity:
Macroperforate: >2.5µm
umbilical or test sutures:
Strongly depressed
final-whorl chambers:
4-4.5
N.B. These characters are used for advanced search. N/A - not applicable
Biogeography and Palaeobiology
Geographic distributionEssentially a worldwide distribution in the low to high latitudes. [Olsson et al. 1999]
Aze et al. 2011 summary: Cosmopolitan; based on Olsson et al. (1999) Isotope paleobiologyNo data available. [Olsson et al. 1999] Aze et al. 2011 ecogroup 3 - Open ocean thermocline. Based on light _13C and relatively heavy _18O. Sources cited by Aze et al. 2011 (appendix S3): Coxall et al. (2000) Phylogenetic relationsAlthough we agree with Blow (1979) that the distinction between the wall texture of eoglobigerinids and subbotinids is one of degree rather than kind, we view trivialis as the earliest representative of Subbotina (in contrast to Blow, 1979, who retained it in Eoglobigerina) and the main lineage that ultimately gave rise to the late Paleogene-Neogene spinose globigerinid radiation (see also Pearson, 1993; Liu and Olsson, 1994). [Olsson et al. 1999]
Geological Range: Notes: Zone Pa to Zone P2. [Olsson et al. 1999] Last occurrence (top): within P2 zone (62.29-62.60Ma, top in Danian stage). Data source: Olsson et al. 1999 First occurrence (base): within P1a subzone (65.25-65.72Ma, base in Danian stage). Data source: Koutsoukos 2014
Plot of occurrence data:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested.
Grey shading between taxa indicates intergrading species within an anagenetic lineage (data from
Lamyman et al. 2026).
Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 32
References:
Blow, W. H. (1979). The Cainozoic Globigerinida: A study of the morphology, taxonomy, evolutionary relationships and stratigraphical distribution of some Globigerinida (mainly Globigerinacea). E. J. Brill, Leiden. 2: 1-1413. gs
Huber, B. T. (1991b). Maestrichtian planktonic foraminifer biostratigraphy and the Cretaceous/Tertiary boundary at ODP Hole 738C (Kerguelen Plateau, southern Indian Ocean). Proceedings of the Ocean Drilling Program, Scientific Results. 119: 451-465. gs
Koutsoukos, E. (2014). Phenotypic plasticity, speciation, and phylogeny in Early Danian planktic foraminifera. Journal of Foraminiferal Research. 44: 109-142. gs
Olsson, R. K., Hemleben, C., Berggren, W. A. & Liu, C. (1992). Wall Texture Classification of planktonic foraminifera genera in the Lower Danian. Journal of Foraminiferal Research. 22(3): 195-213. gs
Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. (85): 1-252. gs
Shutskaya, E. K. (1970b). Stratigrafiya, foraminifery i paleogeografiya nizhnego paleogena Kryma, predkavkaz'ya i zapadnoi chadsti srednei azii [Stratigraphy, Foraminifera and Paleogeography of the Lower Paleogene in the Crimea, Precaucasus and the Western Part of Central Asia]. Trudy Vsesoyuznego Neftyanogo Nauchno-Issledovatel'skogo Geologo-Razvedochnogo Instituta (VNIGRI). 70(1): 256-. gs
Stott, L. D. & Kennett, J. P. (1990). The Paleoceanographic and Paleoclimatic signature of the Cretaceous/Paleogene boundary in the Antarctic: Stable isotopic results from ODP Leg 113. Proceedings of the Ocean Drilling Program, Scientific Results. 113: 829-848. gs
Subbotina, N. N. (1953). Foraminiferes fossiles d'URSS Globigerinidae, Globorotaliidae, Hantkeninidae. Bureau de Recherches Geologiques et Minieres. 2239: 1-144. gs
Subbotina trivialis compiled by the pforams@mikrotax project teamviewed: 18-7-2026
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holotype: G. trivialis
