Lysagoraceras lagowiense (Gürich, 1896) from the Platyclymenia Zone, Famennian, Łagów-Dule, Poland. 1.  Phragrnocone in ventral (a) and lateral (b) view. 2. Adult specimen in lateral (a) and ventral (b) views. 3. Adult specimen in lateral (a) and ventral (b) views. 4. Adult specimen in ventral (a) and lateral (b) views. 5. Very small adult specimen in ventral (a) and lateral (b ) views.

Lysagoraceras lagowiense (Gürich, 1896) from Platyclymenia Zone, Famennian, Łagów-Dule, Holy Cross Mts, Poland; reconstructed adult shell in lateral and ventral views, and the outline of its aperture (a), and longitudinal section through a siphuncle (b).

Diagnoza

Elongated shell almost straight at the juvenile stage but strongly exogastrically curved at the end of mature phragmocone.

Porównanie

L. lagowiense differs from the associated  L. subfusiforme in its considerably curved terminal part of the mature shell. It resembles Gonatocyrtoceras longissimum in shell shape, but differs in simple mature aperture and marginal position of the siphuncle which is also smaller in diameter. The size of mature shell varies, which may be correlated with the extent of adapertural shell curvature . As a rule, the smaller a specimen, the less curved is its shell. Extremely small specimens of L. lagowiense are hard to be distinguished from L. subfusiforme. There is also a considerable variability in the length of the mature living chamber.

Autekologia

Występowanie geograficzne

Dule ravine at Łagów, Poland

Zasięg czasowy

probably the Platyclymenia Zone (Conditolepis marginifera Zone).

Materiały muzealne

ZPAL N/128, 143, 144, 147, 151
UWR 3228s

Literatura

Dzik, J. 1984. Phylogeny of the Nautiloidea. Palaeontologia Polonica 45, 1-255