Emendation of the foraminiferal genus &amp;lt;i&amp;gt;Cribrostomoides&amp;lt;/i&amp;gt; Cushman, 1910, and its taxonomic implications

Robert W Jones,John E Whittaker,Heike Bender,Michael A Kaminski,Michael A Charnock

doi:10.1144/jm.12.2.181

Emendation of the foraminiferal genus &lt;i&gt;Cribrostomoides&lt;/i&gt; Cushman, 1910, and its taxonomic implications

Robert W Jones, John E Whittaker + Show 3 more

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https://doi.org/10.1144/jm.12.2.181

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Abstract

Abstract. A review of the taxonomic history of the agglutinated (benthonic) foraminiferal genus Cribrostomoides Cushman, 1910 reveals much confusion concerning its type species, coiling mode and apertural characteristics. We believe the originally designated type species of Cribrostomoides Cushman, 1910, C. bradyi Cushman, 1910, to be no more than varietally (i.e. infra-subspecifically) distinct from, and therefore a junior synonym of, Haplophragmoides subglobosus Cushman, 1910. The coiling of Cribrostomoides, as typified by C. subglobosus (Cushman, 1910), is in the form of an involute streptospire characterised by a repeated alternation in axis. The aperture of the genus is equatorially or asymmetrically placed and interio-areal and single (in megalospheric and juvenile microspheric specimens) to areal and multiple (in microspheric adults). In order to stabilise the concept of Cribrostomoides, we have designated lectotypes for both C. bradyi and H. subglobosus, and have also emended the generic diagnosis of Loeblich and Tappan (1987). Criteria for the discrimination of Cribrostomoides emend, herein and allied genera are tabulated.

Highlights

INTRODUCTIONThe lituolid (agglutinated benthonic foraminiferal) genus CI.ibrostcimoidcs Cushman, 1910 is an ubiquitous component of modern decp-sea faunas
The lituolid genus CI.ibrostcimoidcs Cushman, 1910 is an ubiquitous component of modern decp-sea faunas
(2) On the coiling mode The widely-held belief that the chamber arrangement in the genus Cribrostomoides is planispiral is in our opinion untenable

Summary

INTRODUCTION

The lituolid (agglutinated benthonic foraminiferal) genus CI.ibrostcimoidcs Cushman, 1910 is an ubiquitous component of modern decp-sea faunas. (2) On the coiling mode The widely-held belief (e.g. of Cushman, 1910, Frizzell and Schwartz, 1950, and Loeblich & Tappan, 1964) that the chamber arrangement in the genus Cribrostomoides is planispiral is in our opinion untenable This was first called into question by the work of Hoglund 1947: 144-145), who noted that Labrospira subglobosa (G.O. Sars) (sic) (which he regarded as a senior synonym of Cribrostomoides bradyi Cushman) "is not formed as a completely flat spiral", that "this is frequently plainly visible in the last volution, which is more or less twisted" and that "the irregularity is noticeable in the initial portion, where the arrangement of the chambers is difficult to determine in a section".

I Evolute streptospiral Interio-areal

I Buzasina