Selindeochrea cf. tecta, Val'kov, 1982

Kouchinsky, Artem, Bengtson, Stefan, Landing, Ed, Steiner, Michael, Vendrasco, Michael & Ziegler, Karen, 2017, Terreneuvian stratigraphy and faunas from the Anabar Uplift, Siberia, Acta Palaeontologica Polonica 62 (2), pp. 311-440 : 413-414

publication ID

https://doi.org/ 10.4202/app.00289.2016

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https://treatment.plazi.org/id/03AD87A8-FFFD-6D40-FCCF-FAF263668130

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scientific name

Selindeochrea cf. tecta
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Selindeochrea cf. tecta Val’kov, 1982

Fig. 70 View Fig .

Material.—About 20 phosphatic and glauconitised internal moulds, including figured SMNH X3778‒3780, 5986, from samples 3/10 (section 3, Fig. 3), 5a/34.5 and 5a/34.75 (section 96-5a, Fig. 2 View Fig ), Medvezhya and Emyaksin formations. Correlated with the upper Fortunian and lower part of the Cambrian Stage 2.

Description.—Tubes with three prominent longitudinal lobes twisted clockwise (from apex to the aperture, in the direction of growth) through several revolutions. Outer surface covered with undulating growth lines. Lumen (internal mould) with three elongated lobes with distal parts twisted up to 90°. Adapically, the lobes are lower and not twisted ( Fig. 70C View Fig 2 View Fig ). The lobes are separated by V-shaped grooves that are shallow adapically.

Remarks.— Selindeocrea tecta has straight trapezoidal lobes similar to those in Fig. 70D View Fig (see Kouchinsky et al. 2009). Unlike S. tecta , the direction of twist as described herein is clockwise in all of the available S. cf. tecta specimens, but this feature does not necessarily have to be an invariant character. Val’kov (1987: 109, pl. 13: 4‒13) described similar forms with curved distal parts of the lobes as observed in cross-sections as Anabarites cf. tricarinatus Missarzhevsky in Rozanov et al., 1969 from the lower Erkeket Formation of the Olenyok Uplift, northern Siberia. Examination of the fossils chemically extracted by Val’kov from sample 846 yielded ca. 20 poorly preserved internal moulds (AK personal observations) that are twisted clockwise in the direction of growth and similar to Selindeochrea cf. tecta .

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