Plate I.


A-E. Transmitted light photograph from holotype and paratypes


scale bars = 100 m.

Type location: Nazaré Canyon 4405 m.

Bithekammina occulta Aranda da Silva, Gooday, Pearse and Cunha 2011


Class Polythalamea

Order Astrorhizia

Superfamily Astrorhizoidea

Family Saccamminida

Genus Bithekammina Aranda da Silva, Gooday, Pearse and Cunha 2011

Species Bithekammina occulta Aranda da Silva, Gooday, Pearse and Cunha 2011

Bithekammina occulta, a new monothalamous agglutinated foraminiferan (‘saccamminid’) was collected in multicore samples at 4400 m on the terrace of the lower Nazaré Canyon on the Portuguese margin. The test is spherical to oval, up to ~400 μm in length, with a simple circular aperture. The wall has a very smooth surface with a distinct sheen in reflected light. It is <10 μm thick and composed of very fine agglutinated plate-like clay particles and a thin inner organic layer. The most distinctive feature of the new species is that the test is contained within an agglutinated case (‘secondary test’) composed mainly of larger (10–50 μm) quartz grains. The case is equipped with a long, narrow tube that originates near the aperture of the inner test and presumably acts as a channel through which pseudopodia are deployed. Secondary agglutinated structures have been described in a number of foraminifera, but never before in a ‘saccamminid’.


Plate II.


A and B. Reflected and transmitted light photographs. E–H. SEM images of the same specimen. E. Entire test, which crumpled when dried onto the stub. F–H. Details of agglutinated particles. Scale bars = 100 μm except where indicated otherwise.

Plate III.


SEM images of the outer case of specimen shown in Plate 2, B, C. Detail of the tubular extension showing organic lining. D. Surface of tubular extension. E,

F. Details of main part of casing. Scale bars = 100 μm (A), 20 μm (B, E), 10 μm (D, F), 5 μm (C).

X-ray microanalysis of the surface of the ‘saccamminid’ test

X-ray microanalysis of a larger grain in the outer agglutinated case

 

- There is no molecular data for this species a present

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