Figure 8 in Ontogeny and evolutionary significance of a new acrotretide brachiopod genus from Cambrian Series 2 of South China

Figure 8. Ontogenetic development of ventral valve of Palaeotreta zhujiahensis from the Shuijingtuo Formation of western Hubei. A–F, ventral valves demonstrating pedicle foramen forming stage (T1); A, oblique dorsal view of a very small conjoined specimen showing unrestricted pedicle notch, ELI-AJH 8-1-2-B AF12; B, lateral view of a small conjoined specimen, ELI-AJH 8-2-3 AD2-07; C, posterior view, box indicates the area shown in Figure 9E, ELI-AJH S05 AG07; D, interior view of C; E, oblique view of a larger juvenile, ELI-AJH 8-2-3 AC-27; F, posterior view of E, note 'U'-shaped pedicle notch, box indicates the area shown in Figure 9D; G, lateral view, indicating pedicle foramen-enclosing stage (T2), showing enclosed pedicle foramen outside of the metamorphic shell, ELI-AJH 8-2-D AD2-12; H–N, intertrough-increasing stage (T3); H, posterior view, ELI-AJH S05 AF-16; I–N, adult with short intertrough, ELI-AJH 8-2-1 CE-03; I, exterior view; J, interior view; K, oblique lateral view; L, lateral view; M, posterior view, note the posterior migration of enclosed pedicle foramen, outside the metamorphic shell; N, oblique anterior view.