Specimen from Świdnik blocks, borehole M7 (depth 1126-1131 m)

Diagnoza

Evolute juvenile stages with sharp umbilical edges and oxyconic adults. Section of coils initially trapezoidal or at least semi-lunar; umbilicus sharp-edged and of variable width; ornamentation with transverse ribs or striae forming  at the young stage an external concave lobe that disappears most often in the adult stage; ribs form a wide sinus on the flanks with its center in the middle; of longitudinal striae absent; suture with an outer lobe very wide, divided by a high median saddle, but narrow at the top; first lateral saddle rounded, rather narrow; lateral lobe pointed at its base, wider than the lateral saddle; wide, low second side saddle

Porównanie

Juveniles difficult to distinguish from H. diadema (Beyrich), but adults differ in the growth lines forming a single but broad convex lobe instead of double lobes; much stronger striae which in H. diadema resemble the fine striation of H. striolatum (Phillips); edge of the umbilicus is often sharper; spiral striae near the umbilicus occur in some specimens of H. diadema; saddles are narrower in H. beyrichianum.

Autekologia

Występowanie geograficzne

Great Britain (England: Devonshire and Yorkshire, Wales: Pembrokeshire); Ireland (Care and Limerick County); Belgium (Hainaut, Liège, Namur); Germany (Rhenish Slate Mts.); Poland (Lublin Coal Basin); Morocco (Tafilalt, Koudiat ès Senn)

Zasięg czasowy

Carboniferous; Bashkirian (Arnsbergian – Alportian)

Materiały muzealne

Literatura

Bojkowski, K. 1979. Goniatyty z karbonu Górnośląskiego i Lubelskiego Zagłębia Węglowego.  Biuletyn Instytutu Geologicznego 311: 5-68.

Dzik, J. 1997. Emergence and succession of Carboniferous conodont and ammonoid communities in the Polish part of the Variscan sea. Acta Palaeontologica Polonica 42, 57

Korejwo, K. 1969. Stratigraphy and palaeogeography of the Namurian in the Polish Lowland. Acta Geologica Polonica 19 (4): 609-70.

Korejwo, K. 1986. Biostratigraphy of the Carboniferous deposits of the Świdnik blocks (Lublin Coal Basin). Acta Geologica Polonica 36 (4): 337-346.

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