Catalog - Globigerinopsoides

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Globigerinopsoides

Citation: Globigerinopsoides Cita & Mazzola 1970

Type species: Globigerinopsoides algeriana Cita & Mazzola 1970

Type age (chronostrat): Middle-Upper Miocene

Diagnosis. Test free, trochospiral; chambers subspherical to ovate; wall calcareous, perforate, radial in structure; surface cancellate or spinose; primary aperture in the early stage interiomarginal, umbilical-extraumbilical, later extending on the spiral side (spiroumbilical); secondary sutural aperture(s) on the spiral side. Family Globigerinidae; subfamily Globigerininae. Monotypic.

Discussion. - The genus Globigerinopsoides is very similar to Globigerinopsis Bolli, 1962, from which it differs for the occurrence of secondary apertures. On the basis of the available data. the two genera have rather similar ranges. In fact, Globigerinopsis has been originally described from the middle Miocene of Venezuela ancl the Dominican Republic (Globorotalia fohsi robusta Zone). Globigerinopsoides is described from the middle-late Miocene of Algeria (Globigerina nepenthes Zone of Courrier and Mazzola, Algeria, Serv. Carte Geol.. in press). However. they do not seem to co-occur.

The genus Globigerinopsis has been compared to Globigerina and Hastigerinella (see Bolli, 1962; Loeblich ancl Tappan, 1964). It is in some way intermediate between Globigerina - from which it differs in the spiroumbilical aperture - and Hastigerinella - from which it differs lacking the radially elongate or clavate chambers. A derivation from Globigerina is very likely. A derivation of Globigerinopsis aguasayensis from Hastigerina siphonifera praesiphonifera is considered likely by Blow (1969).

The primary aperture of Globigerinopsoides is never so extended along the spiral suture as it is in the type-species of the genus. Globigerinopsis (G. aguasayensis), so that no affinity may be noticed with Hastigerinella. Globigerinopsoides appears as a Globigerinoides with a modified primary aperture, which is displaced from its usual position. A derivation of the former from the latter is very likely. Therefore no direct relationship appears to exist between Globigerinopsis Bolli. 1962 and Globigerinopsoides. but only a morphologic affinity. This assumption is supported by the occurrence of accessory structures (bridge-like processes) connected with the primary aperture, as observed in the type-species Globigerinopsoides algeriana. Similar structures cannot be found in taxa referred to the genus Globigerinopsis.

The sype species was Globigerinopsoides algeriana Cita & Mazzola 1970 was described in the same pulbication. So the genus was explicitly treated as feminine in the original publication and should be treated as feminine.

References:

Blow, W. H. (1969). Late middle Eocene to Recent planktonic foraminiferal biostratigraphy. In, Bronnimann, P. & Renz, H. H. (eds) Proceedings of the First International Conference on Planktonic Microfossils, Geneva, 1967. E J Brill, Leiden 380-381. gs

Bolli, H. M. (1962). Globigerinopsis, a new genus of the foraminiferal family Globigerinidae. Eclogae Geologicae Helvetiae. 55: 282-284. gs

Cita, M. B. & Mazzola, G. (1970). Globigerinopsoides gen n. from the Miocene of Algeria. Rivista Italiana di Paleontologia e Stratigrafia. 76: 465-476. gs

Loeblich, A. R. & Tappan, H. (1964b). Sarcodina, Chiefly "Thecamoebians" and Foraminiferida. In, Moore, R. C. (ed.) Treatise on Invertebrate Paleontology, Protista 2, pt. C. University of Kansas Press, Lawrence 1-900. gs

CATALOG OF ORIGINAL DESCRIPTIONS: Globigerinopsoides Cita & Mazzola 1970

Globigerinopsoides

References:

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