Diagnoza

Shell rather large to very large, transverse, with lateral and anterior commissures merged into one approximately semi-elliptic line; cardinal margin more or less straight; ventral valve somewhat convex in the posterior region, otherwise flat; dorsal valve moderately to strongly convex; maximal width at hinge line; ornamentation developed on the entire shell, consisting of smooth (not crenulate) radial costellae of different height and thickness, separated by wider furrows; costellae arising by intercalation; muscle scars indistinct.

Porównanie

Easily distinguished from the common Xystostrophia umbraculum (von Schlotheim 1820) by its smooth costellae and greater width to length ratio.

Autekologia

Występowanie geograficzne

Eifel Mts (Germany) and Holy Cross Mts. (Poland).

Zasięg czasowy

Mid Devonian

Materiały muzealne

3 incomplete specimens and one fragment from Skaly and Pokrzywianka (ZPAL Bp VII/3714, L PZ-D.536, olim 781); 3 dorsal valves, one ventral valve and several fragments from outcrop SW-2 (ZPAL Bp 48/16/1/1-8); 3 fragments from Sitka, L PZ-D.941, olim 684; articulated shells (SMF 264, MB.B.2412) from the Eifel region.

Literatura

Biernat, G. 1966. Middle Devonian Brachiopods from the Bodzentyn Syncline (Holy Cross Mountains, Poland). Palaeontologica Polonica 17: 1-162. Pls. 1-32; Warszawa.

Halamski, A.T. 2009. Middle Devonian Brachiopods from the northern Part of the Holy Cross Mountains, Poland in relation to selected coeval faunas. Part One: Introduction, Lingulida, Craniida, Strophomenida, Productida, Protorthida, Orthida. Palaeontographica Abteilung A, 287: 41-98.

Kayser, E. 1871. Die Brachiopoden des Mittel- und Ober-Devon der Eifel.  Z. deutsch. geol. Ges. 23: 491-647, Pls. 9-14; Berlin.

Schnur, J. (1853-1854). Zusammenstellung und Beschreibung samtlicher im Obergangsgebirge der Eifel vorkommenden Brachiopoden, nebst Abbildungen derselben. - Palaeontographica 3: 169-253, Pls. 22-29, 31-32, 32b, 33-45, Cassel. (pp. 169-192 published 27'h July 1853; pp. 193-216 published September 1853; pp. 217-248 and plates published 1854).

Siemiradzki, J. 1909a. Zbiory L. Zejsznera z kieleckiego dewonu. Spraw. Kom. fizyogr. 43 (3): 62-94, Pls. 1-2; Kraków.