Tirolonautilus undefined-1

Tirolonautilus sp. 1 Fig. 39 Material examined IRAN – West Azerbaijan • 1 specimen; Aras Valley; Zal Member of the Ali Bashi Formation (early Changhsingian); 2011; Korn et al. leg.; illustrated in Fig. 39; MB.C.32065. Description Specimen MB.C.32065 is a distorted individual with a diameter of 62 mm (Fig. 39). Despite being laterally crushed and deformed, it still exhibits recognisable conch, sculpture, and suture characters. Its shape is thinly discoidal and subinvolute, with clearly parallel flanks. The ventrolateral shoulder is pronounced, and the venter is concave with a rather deep longitudinal groove. On each side, between this groove and the ventrolateral shoulder, there are two rows of nodes elongated in the growth direction. These nodes create a tuberculate outline of the whorl spiral. On the last volution, there are 15 of these nodes. Remarks The specimen is too poorly preserved for a more detailed discussion. It appears that the umbilicus is narrower than in Tirolonautilus sp. 2.