Fig. 2 in Thomasaria vs. Pyramidalia conundrum in Devonian brachiopod systematics solved: An argument to formalize epitypification under the ICZN

Fig. 2. Spiriferide brachiopod Thomasaria simplex (Phillips, 1841) from the Middle Devonian of south-western England, UK (type region). A–C. Articulated shells (TCD 16991c, A; TCD 16991b, B; TCD 16991a, C) from Port Stephens, in dorsal (A1–C1), ventral (A2–C2), lateral (A3–C3), anterior (A4–C4), and posterior (A5–C5) views. D. Lectotype, articulated shell GSM 6915 from Wolborough, in dorsal (D1), ventral (D2), lateral (D3), anterior (D4), and posterior (D5) views. Reproduced with the permission of the British Geological Survey ©UKRI. All rights reserved. E. Topotype, articulated shell NHMUK PI B 2807 (specimen serially sectioned, see Fig. 3) from Wolborough, in dorsal (E1), ventral (E2), lateral (E3), anterior (E4), and posterior (E5) views, enlargement (SEM micrograph) of the secondary shell layer showing impunctate condition (E6). F. Articulated shell TCD 16991d from Port Stephens, fragmentary posterior view showing the delthyrium partially closed by a convex pseudodeltidium.