FIGURE 6. Saurorhamphus sp. from Sierra Madre Formation. 1, IHNFG 2983, from El Espinal quarry. 2 and 3, IHNFG 2660, part and conterpart of the head of the same specimen from El Chango quarry. 4, IHNFG 2667 specimen from El Espinal quarry. 5, impression of a scale of IHNFG 2983, from the rectangle marked in 1. Abbreviations: af, anal fin; df, dorsal fin; dfr 1, dorsal fin ray 1; lls, lateral line scales; mds, mid-dorsal scute; pop, preopercle; pvf, pelvic fin. Scale bars equal 50 mm.