Fig. 12 in The Early Cambrian (Botomian) stem group brachiopod Mickwitzia from Northeast Greenland

Fig. 12. Mickwitzia cf. occidens Walcott. A. Fragmentary mature valve (indeterminate) MGUH 26317. A1. Exfoliated interior surface showing numerous acrotretoid−type columns and scattered large tubes, position of A2 and A3 indicated; scale bar 50 µm. A2. Detail of A1 showing single large tube with adhering cocci and numerous acrotretoid−type columns; scale bar 10 µm. A3. Detail of A1 showing numerous acrotretoid−type columns, some of which have a central canal of varying diameter or are completely filled; scale bar 10 µm. A4. Detail of A1 showing lamina perforated by empty large tube (marked by arrow) and +