Fig. 7 in Early ontogeny and palaeoecology of the Mid-Miocene rissoid gastropods of the Central Paratethys

Fig. 7. Four species of Alvania (Alvania) Risso, 1826. A. Alvania (Alvania) oceani (d'Orbigny, 1852). Specimen (NHMW 2002z0030/0012) from the Badenian of Steinebrunn, Lower Austria (A1). Protoconch of the same specimen as in A1 in lateral view (A2). The protoconch is terminated by a slightly thickened, fractionated sinusigera notch. B. Alvania (Alvania) perregularis (Sacco, 1895). Specimen (NHMW 2002z0030/0013) from the Early Badenian of Sedlec/Nový Rybník, Czech Republic (B2). Lateral and apical view of the protoconch of the same specimen as in B2 (B1, B3). The protoconch is terminated by a sinusigera notch. Detailed apical view of the initial whorl of the same protoconch as in B3 (B4). The embryonic shell consists of one inflated whorl, which is terminated by a thickened rim, reflecting the thickened apertural margin of the hatchling. C. Alvania (Alvania) transiens (Sacco, 1895). Specimen (NHMW 2002z0030/0014) from the Badenian of Steinebrunn, Lower Austria (C1). Protoconch of the same specimen as in C1 in lateral and apical view (C2, C3). The larval shell is sculptured by spiral rows of tubercles. It is terminated by a well developed sinusigera notch. D. Alvania (Alvania) schwartzi (Hörnes, 1865). Specimen (NHMW 2002z0030/0015) from the Badenian of Steinebrunn, Lower Austria (D2). Lateral and apical views of the protoconch of the same specimen as in D2 (D1, D3, D4). The protoconch is terminated by a well developed sinusigera notch. Detailed view of the initial whorl of the same protoconch as in D4 (D5). The embryonic shell is demarcated from the subsequent larval shell by a thickened rim.