Alispira gracilis

Alispira gracilis (Nikiforova in Nikiforova & Andreeva, 1961) Zygospira (Alispira) gracilis Nikiforova in Nikiforova & Andreeva, 1961: 244, pl. LIII, figs 1-8. Alispira gracilis – Rubel 1970: 25, pl. XIII, figs 16- 22. — Lopushinskaya 1976: 63, pl. XI, figs 1, 2. MATERIAL EXAMINED. — Two spe...

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Bibliographic Details
Main Author: Modzalevskaya, Tatiana L.
Format: Text
Language:unknown
Published: Zenodo 2003
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Online Access:https://dx.doi.org/10.5281/zenodo.5463795
https://zenodo.org/record/5463795
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Summary:Alispira gracilis (Nikiforova in Nikiforova & Andreeva, 1961) Zygospira (Alispira) gracilis Nikiforova in Nikiforova & Andreeva, 1961: 244, pl. LIII, figs 1-8. Alispira gracilis – Rubel 1970: 25, pl. XIII, figs 16- 22. — Lopushinskaya 1976: 63, pl. XI, figs 1, 2. MATERIAL EXAMINED. — Two specimens from loc. 12, bed 112, Matusevich River, October Revolution Island (Männik et al . 2002: figs 2, 5); Vodopad Formation. REMARKS Specimens have a ventral valve with a keel on the umbo, and an acute, weakly incurved beak. The sinus is well defined: arising at the umbo, it is bordered by larger ribs and commonly bears one or two weaker ones. The lateral ribs increase in width anteriorly. The number of ribs multiplies by bifurcation and intercalation. Based on these features the specimens are assigned to Alispira gracilis which is typical of the Chamba and Talikit formations of East Siberia. Homeospira ? sp. (Poulsen 1934: 19, pl. 2, figs 21, 22) from the Cape Schuchert Formation of Greenland resembles A . gracilis . O. I. Nikiforova thought that, in reality, the last one should also be assigned to A . gracilis (Nikiforova & Andreeva 1961). : Published as part of Modzalevskaya, Tatiana L., 2003, Silurian and Devonian brachiopods from Severnaya Zemlya (Russian Arctic), pp. 73-107 in Geodiversitas 25 (1) on page 90, DOI: 10.5281/zenodo.5375016 : {"references": ["NIKIFOROVA O. I. & ANDREEVA O. N. 1961. - [Ordovician and Silurian stratigraphy of Siberian Platform and its paleontological grounds (Brachiopods)]. Biostratigrafiya paleozoya Sibirskoj platformy. Trudy VSEGEI, novaya seriya 56, 1, 412 p. (in Russian).", "RUBEL M. 1970. - Brachiopods Pentamerida and Spiriferida of the Silurian of Estonia. Valgus, Tallin, 75 p.", "LOPUSHINSKAYA T. V. 1976. - [Silurian brachiopods and stratigraphy of the North of Siberian Platform]. Trudy SNIIGGiMS'a 199, 104 p. (in Russian).", "MANNIK P., MENNER V. V., MATUKHIN R. G. & KURSS V. 2002. - Silurian and Devonian strata on the Severnaya Zemlya and Sedov archipelagos (Russia). Geodiversitas 24 (1): 99 - 122.", "POULSEN CHR. 1934. - The silurian faunas of North Greenland. I: The fauna of the Cape Schuchert Formation. Meddelelser om Gronland 72 (1), 46 p."]}