Catalog - Marginotruncana scorpionis Catalog - Marginotruncana scorpionis

CATALOG OF ORIGINAL DESCRIPTIONS: Marginotruncana scorpionis Lamolda 1977

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.


Higher levels: pf_cat -> M -> Marginotruncana -> Marginotruncana scorpionis
Other pages this level: M. arcaformis, M. bouldinensis, M. caronae, M. paraconcavata, M. paraconcavata veronikae, M. paraventricosa, M. pauperata, M. pileoliformis, M. pseudolinneiana, M. pseudomarginata, M. scorpionis, M. sinuosa

Marginotruncana scorpionis

Citation: Marginotruncana scorpionis Lamolda 1977
Taxonomic rank: species
Type specimens: 1057
Type age (chronostrat): Uppermost Turonian
Type locality: Valle de Mena (Burgos Province, Spain), local road from Mercadillo to Arceniega.
Type repository: Bilbao, Spain; Bilbao University - BIPA (Paleontological Collection)

Current identification/main database link: Marginotruncana pseudolinneiana Pessagno 1967


Original Description

Test low trochospiral, umbilicoconvex. Fourteen to 16 chambers in 2.5 whorls, 5 to 6 in outer whorl. Equatorial periphery truncate, with two keels separated by an intercarinal band that is narrower on last chambers. Sutures on spiral side narrower on last chambers. Sutures on spiral side curved, raised and beaded, delimiting semicircular to subpetaloid chambers; sutures on ventral side likewise raised and beaded, and, by surronding umbilicus, making an umbilical shoulder. Umbilicusmedium to large in size, its diameter about 1/3 of diameter of test; covered by 'portici' in well-preserved specimens. Primary aperture interiomarginal, extraumbilical-umbilical in position. Test surface generally smooth, although early chambers of outer whorl are rugose umbilically. Wall perforate, except for keel, raised sutures and umbilical shoulder, which are imperforate.

Extra details from original publication

Derivation of name: Discovery under the zodiacal sign of Scorpio.

Remarks: M. scorpionis is differentiated from M. renzi (Gandolfi) by having two keels and by having chambers with the axial section subrectangular in the inner whorls. like M. pseudolinneiana Pessagno. instead of having chambers with the axial section rhomboidal or truncate. and from M. pseudolinneiana Pessagno by having the ventral side distinctly convex rather than flat. M. scorpionis has often been referred to G. tricarinata (Quereau) in assemblages of Turonian-Santonian age. Reichel (1950) cited the passage from specimens of G. tricarinata with a flat ventral side to those that are umbilicoconvex. Hagn and Zeil (1954) and Moorkens (1969) have also illustrated specimens of this taxon as G. tricarinata (Ouereau). Lamolda (1975) cited as G. ct. primitiva Dalbiez specimens that have now been reclassified as M. scorpionis Lamolda. This new species evolved from M. pseudolinneiana Pessagno by adult variation. Populations of the latter species include occasional specimens with an elevated umbilical shoulder on the last chambers; M. scorpionis Lamolda appears when this feature develops on all chambers of the outer whorl.

Occurrence: To date. M. scorpionis is known only in Europe (Bavaria, Belgium, northern Spain). where it is associated with Dicarinella schneegansi (Sigal), D. imbricata (Mornod), M. cf. sigali (Reichel), M. renzi (Gandolfi), M. pseudolinneiana Pessagno, M. fungicamerata (Martirosjan) and M. coronata (Bolli). The first specimens appeared after the extinction of Helvetoglobotruncana helvetica (Bolli).

Range: Uppermost Turonian to Santonian.

References:

Lamolda, M. (1977). Lamolda, M. (1977). Three new species of planktonic foraminifera from the Turonian of northern Spain. Micropaleontology. 23: 470-477. Micropaleontology. 23: 470-477. gs


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Marginotruncana scorpionis compiled by the pforams@mikrotax project team viewed: 17-6-2025

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