Figure 1.
Guiyu oneiros Zhu et al., 2009.
A. New articulated specimen of Guiyu oneiros (V17914, lateral view) from the Kuanti Formation (Late Ludlow, Silurian), Qujing, Yunnan, showing a right dermal pelvic girdle in near-natural position. Red arrow points to the anterior end of the fish. B. Interpretative drawing. Abbreviations: ba.sc, basal scales of pelvic fin; cla, clavicle; cle, cleithrum; icl, interclavicle; ipelv, interpelvic plate; pelv.sp, pelvic fin spine; scap, scapulocoracoid; sdf.sp, second dorsal fin spine; tr.anf, lepidotrichia of anal fin; v.dpg, ventral lamina of dermal pelvic girdle; vrs, ventral ridge scale.
Figure 2.
The holotype (V15541) of Guiyu oneiros Zhu et al., 2009.
A. Interpretative drawing of the part to show the position of the newly identified left pelvic girdle with dermal and endoskeletal components. B–C. Close-up of the counterpart to show the endoskeletal pelvic girdle in internal view (B) and interpretative drawing (C). D–E. Close-up of the part to show the dermal pelvic girdle in lateral view (D) and interpretative drawing (E). Red arrows point to the anterior end of the fish. The red rectangles indicate the close-up areas in Figure 3A and Figure 3B. The double arrows point to the corresponding positions of the fractured interpelvic plate in part (E) and counterpart (C). Abbreviations: br, branchiostegal ray; b.scu, basal scute; cla, clavicle; cle, cleithrum; dpg, dermal pelvic girdle; endo.pg, endoskeletal pelvic girdle; gu, gular; ipelv, interpelvic plate; l.dpg, lateral lamina of dermal pelvic girdle; lj, lower jaw; m.ext, median extrascapular; mx, maxillary; op, opercular; pa, parietal shield; pf.sp, pelvic fin spine; po, foramina for pterygial nerves and vessels; pop, preopercular; ppa, postparietal shield; sdf.sp, second dorsal fin spine; sop, subopercular; sp, pectoral fin spine; tr, lepidotrichia; v.dpg, ventral lamina of dermal pelvic girdle; vrs, ventral ridge scale.
Figure 3.
Guiyu oneiros Zhu et al., 2009.
A. Close-up of the holotype (in part) to show the dermal pelvic girdle in lateral view. B. Close-up of the holotype (in counterpart) to show the endoskeletal pelvic girdle in internal view. C. Tentative life restoration in ventral view to show the paired pelvic girdles and unpaired interpelvic plate. Red arrows point to the anterior end of the fish. Abbreviations: endo.pg, endoskeletal pelvic girdle; l.dpg, lateral lamina of dermal pelvic girdle; po, foramina for pterygial nerves and vessels; v.dpg, ventral lamina of dermal pelvic girdle.
Figure 4.
Guiyu oneiros Zhu et al., 2009.
A. Close-up of the three median dorsal plates (Md1-Md3) of the holotype V15541. B–C. A disarticulated third median dorsal plate (Md3) bearing the first dorsal fin spine in external (B) and internal (C) views, V17914.2. D. A disarticulated third median dorsal plate (Md3) in external view, V17914.3. E. Revised restoration of Guiyu oneiros in lateral view, based on [24] for the cranial portion, and new data in this work. Abbreviations: Md1–Md3, first to third median dorsal plates, with the third bearing the first dorsal fin spine and the endoskelatal basal plate.
Figure 5.
Life restoration of Guiyu oneiros from the Kuanti Formation (Late Ludlow, Silurian), Qujing, Yunnan, China.
Figure 6.
Psarolepis romeri Yu, 1998, from the Lower Devonian Xitun Formation (Lochkovian) of Qujing, Yunnan.
A–E. Disarticulated left pelvic girdle in lateral (A), ventral (B), internal (C) and posterior (D–E) views, V17913.2. F–J. Disarticulated left pelvic girdle in lateral (F), ventral (G), internal (H) and posterior (I–J) views, V17913.1. K. Disarticulated right pelvic girdle in ventral view, V17913.5. L. Disarticulated right pelvic girdle in ventral view, V17913.4. M. Disarticulated left pelvic girdle in ventral view, V17913.3. N. Disarticulated left pectoral girdle in ventrolateral view, V15544.1. E and J are SEM photos. All scale bars equal 1 mm. Abbreviations: art.pf, articulation facet for pelvic fin; endo.pg, endoskeletal pelvic girdle; l.dpg, lateral lamina of dermal pelvic girdle; pbr, postbranchial lamina; pf.sp, pelvic fin spine; po, foramina for pterygial nerves and vessels; sp, pectoral fin spine; v.dpg, ventral lamina of dermal pelvic girdle.
Figure 7.
Gnathostome pelvic girdle evolution.
The cladogram is based on the trees in Zhu et al. [18], [20]. We adopt the grouping of Guiyu with Psarolepis [20] and the alternative positions (I and II) of Psarolepis (either a stem sarcopterygian or a stem osteichthyan) [18] as our working hypotheses. Drawing of placoderm pelvic girdle (Murrindalaspis in posterior view) from [8]. Dermal pelvic girdles (including plates and spines) in yellow; endoskeletal pelvic girdles in blue. Abbreviations: -dpg, loss of dermal pelvic girdle; dpg, dermal pelvic girdle; mono, monobasal pelvic fin articulation; poly, polybasal pelvic fin articulation.