Diagnoza

Thick-discoidal shell with subcrescentic cross section, somewhat flattened on ventral and lateral surfaces; umbilicus moderately large, about one-fourth the entire diameter; constrictions strong, about four to a volution; somewhat sigmoid, with a backward curve over the ventral surface; surface marked by rather sharp, strongly elevated about 36 revolving lirae, separated by relatively broad, rounded striae, which are narrower over the ventral area and broader toward the umbilicus; a rather narrow siphonal saddle indented on top; the two lateral saddles are relatively large and broad, the second one being lower and broader than the first; siphonal lobes are small, narrow, and pointed; the lateral lobes large, pointed, and somewhat lanceolate.

Porównanie

Differs from N. subcirculare mainly by a more open umbilicus, a different course of the growth line and a greater convexity of the shell.

Autekologia

Występowanie geograficzne

Germany (Rhenish Slate Mts., Harz Mts), Poland (fore-Sudetic Monocline and Holy Cross Mts.), Belgium, Kazakhstan, USA (Oklahoma, Arkansas)

Zasięg czasowy

Carboniferous, Serpukhovian-Bashkirian

Materiały muzealne

5 specimens from Gałęzice, Poland

Literatura

Girty, G.H., 1909, The fauna of the Caney Shale of Oklahoma. Bulletin of the U. S. Geological Survey 377: 57-59.

Schmidt, H. 1925. Die carbonischen Goniatiten Deutschlands. Jahrbuch der Preußischen Geologischen Landesanstalt 45 (for 1924), 489–609.

Żakowa, H. 1971. Poziom Goniatites granosus w synklinie galęzickiej (Góry Swiętokrzyskie). Prace lnstytutu Geologicznego 60: 1-137.

Żakowa, H. 1974. Goniatitina from the Uper Visean (Gałęzice Syncline, Holy Cross Mts). Rocznik Polsiego Towarzystwa Geologicznego 44 (1): 3-30.