Catalog - Clavatorella

This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.

Clavatorella

Type species: Hastigerinella bermudezi Bolli 1957

The test is coiled in a low trochospire, evolute throughout ontogeny on the dorsal (spiral) side, the early part of which may be depressed below the level of the dorsal sides of the chambers in the final whorl. The ventral side usually involute, but may become evolute in the later stages of growth, forming a broad but shallow umbilicus which, together with the depression of the dorsal spire, may give the false impression of a biumbilicate, planispiral test. The aperture is a low slit-like opening extending from the umbilicus along the ventral base of the chamber to the equatorial periphery, where it tends to become higher and more widely open. The aperture does not extend across the periphery onto the dorsal side. The aperture is bordered by a regular, well-marked, perforate lip thwughout its length. The chambers are subspherical or ovate in the early stages of growth but later become radially elongate, digitate, or club-shaped. The wall is finely cancellate, perforate throughout, and is composed of radially-arranged bundles of crystals. No imperforate band or carina is present.

The derivation of the generic name Clavatorella is from the Latin word clavator, a cudgel-bearer.

Remarks: The early stages of Clavatorella, new genus, are similar to those of the genus Turborotalia Cushman and Bermudez, 1949, but the genus differs in the later ontogenetic development of radially elongate and clubshaped chambers. Clavatorella differs from Beella Banner and Blow, 1960, in possessing an interiomarginal, umbilical- cxtraumbilical aperture. Clavatorella differs from Bolliella Banner and Blow, 1959, in being trochospirally, not planispirally, coiled, as well as in not having an equatorial symmetrical aperture. Clavatorella differs from Hastigerinella Cushman, 1927, emend. Banner and Blow, 1960 (see Banner and Blow 1960b, p. 24 et seq.) in not being streptospirally coiled and in not having an equatorial symmetrical aperture.

Recently, Lipps (1964) erected the genus Protentella (type species Protentella prolixa Lipps, 1964) for forms with radially elongate chambers, a planispirally coiled test in the adult and with an equatorially symmetrical aperture. This genus seems, without doubt, to be a junior synonym of the genus Bolliella Banner and Blow, 1960. Indeed, the type species of Protentella, i.e., P. prolixa Lipps, may well prove to be a junior synonym of Bolliella adamsi Banner and Blow, the type species of Bolliella. Lipps (1964) ascribed the age of his species to the "Burdigalian Globorotalia fohsi fohsi Zone," but this is strongly doubted here since the form illustrated by him as Turborotalia mayeri (Lipps, 1964, pl. 3, fig. 5a-c; not fig. 4a- c) is most probably Turborotalia acostaensis (Blow). Further, Lipps placed "Globigerinoides" glomerosus glomerosus Blow and "G." glomerosus circularis Blow into synonymy with Candorbulina universa Jedlitschka, but Blow (1956) has previously discussed the reasons for separating "Globigerinoides" glomerosus s. l. from Candorbulina universa and the reasons for referring the latter to Orbulina suturalis Bronnimann. Orbulina suturalis ranges to the Recent, and the forms illustated by Lipps (1964, pl. 2, figs. 6- 7) can and do occur in Recent deposits. In passing, it is noted that Lipps states that his figure 3 (Lipps 1964, p. 121) is after Blow, 1956, text-figure 2, no. 16; this is quite incorrect, as comparison with the literature shows. The present writer believes that the age of the forms recorded by Lipps from the upper Luisian of California could be as young as post-Miocene.

Clavatorella is the Neogene analogue of the Cretaceous praeglobotruncanid genus Clavihedbergella Banner and Blow, 1959, but differs from it by not having a porticus or well-marked relict apertures (Banner and Blow, 1959).

Globigerina radians Egger, 1893, described from the Recent seas, also appears to belong to Clavatorella. The writer has also observed a number of yet undescribed Neogene forms which seem to be referable to this genus.

References:

Blow, W. H. (1965). Clavatorella, a new genus of the Globorotaliidae. Micropaleontology. 11(3): 365-368. gs

Lipps, J. H. (1964). Miocene planktonic foraminifera from Newport Bay, California. Tulane Studies in Geology and Paleontology. 2: 109-133. gs O

CATALOG OF ORIGINAL DESCRIPTIONS: Clavatorella Blow 1965

Clavatorella

References:

Add Comment

Comments

			Clavatorella nicobarensis Srinivasan & Kennett 1974 = Protentella nicobarensis
			Clavatorella paleocenica de Klasz&de Klasz 1986
			Clavatorella salumensis Imam 1998