FIGURE 1. Stemec suntokum gen. et sp. nov. holotype right coracoid (RBCM.EH2014.032.0001.001) from the Sooke Formation, at the southwestern end of Vancouver Island, British Columbia as re-assembled after preparation. 1-4, dorsal (1), medial (2), lateral (3), ventral (4) aspects. Abbreviations: FACL, facies articularis clavicularis; FAHU, facies articularis humeralis; PRO, procoracoid.

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FIGURE 2. Components of Stemec coracoid (RBCM.EH2014.032.0001.001). 1, cross-section of the shaft immediately caudal of the cranial portion (a-a of Figure 1.1); 2, cross-section cranial to the sternal segment (b-b of Figure 1.1); and 3, structural features near the sternal articulation.

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FIGURE 3. Comparison of the acrocoracoid of Plotopterum joaquinensis (LACM 8927) (1 and 3) to Stemec suntokum (RBCM.EH2014.032.0001.001) (2 and 4). 1 and 2, dorsal aspects, 3 and 4, cranial aspects. See Figure 1 for abbreviations.

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FIGURE 4. Map of Carmanah Group surface exposures along western Vancouver Island, British Columbia. A, Brooks Peninsula; B, Nootka (Tatchu Point, Nootka Island, Hesquiat Peninsula, and Flores Island); C, Carmanah (Pachena Point south to Owen Point); and D, Sooke (Port Renfrew south to Sooke) (for additional information, see Johns et al., 2012, figure 1).

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FIGURE 5. Geological context of the Sooke Formation and Carmanah Group rocks, Vancouver Island based on data from Clark and Arnold (1923), Cameron (1980), Muller et al. (1981), Johns et al. (2012).

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FIGURE 6. Cliff-beach exposure of the Sooke Formation. Letters indicate A, sandstone and shell-rich beds with burrows near the base; B, ripples; C, pebble conglomerate and shells; D, shell-rich coquinas and concretions; and E, Mytilus sp. and other shelly materials in cross-laminated and bedded sandstones. Rock hammer 26 cm, walking stick 115 cm.

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FIGURE 7. Casts of coracoids in the Smithsonian Institution, Washington DC, referable to Copepteryx, one of the very large plotopterids from the Oligocene Ashiya Group of Kitakyushu, Japan. 1, Dorsal aspect of shaft lacking the omal portion and 2, Isolated omal portion, ventral aspect. Abbreviations: FASC, facies articularis scapularis; see Figure 1 for others.

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FIGURE 8. Dimensional proportions of the Stemec coracoid (RBCM.EH2014.032.0001.001) and to two much larger plotopterids compared to cormorants, darters, and penguins. All other families of wing-propelled birds have larger values on both axes. Extinct examples are marked by a ‘+’ symbol.

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