Trilobita

Ptychagnostus atavus (Tullberg, 1880)

Synonymy list
1880     Agnostus atavus n. sp. — Tullberg, pp. 14-15, fig. 1:1a-d
2007     Ptychagnostus atavus (Tullberg, 1880) — Ahlberg et al., pp. 710, fig. 2:1-12