Fossil penguins from the Horcon Formation.

A. Skeletal reconstruction of Eudyptes calauina sp. nov. showing the identified elements; and size comparison with the Macaroni penguin E. chrysolophus and the Yellow-eyed penguin Megadyptes antipodes (yellow silhouette). Referred specimens: left humerus (SGO-PV 21451) in (B) cranial, (C) distal and (D) caudal views; proximal fragment of left humerus (SGO-PV 21449) in (E) cranial, (F) proximal and (G) ventral views; (H) proximal fragment of right tibiotarsus (SGO-PV 21447) in cranial view; and (I) distal portion of right tibiotarsus (SGO-PV 21488) in cranial view. Tarsometatarsus of Humboldt penguin Spheniscus humboldti (J) and Northern Rockhopper penguin E. moseleyi (K). Holotype: right tarsometatarsus attributed to an adult (SGO-PV 21487) in (L) dorsal, (M) plantar, (N) medial, (O) lateral, (P) proximal and (Q) distal views. Paratype: right tarsometatarsus attributed to a subadult (SGO-PV 21444) in (R) dorsal, (S) plantar, (T) medial, (U) lateral, (V) proximal and (W) distal views. Spheniscidae indet.: (X) proximal fragment of right radius (SGO-PV 21450) in ventral view; (Y) right ulna (SGO-PV 21455) in ventral view; and (Z) right carpometacarpus (SGO-PV 21454) in ventral view. Silhouettes (green for E. calauina, blue for Spheniscidae indet.) based on complementary specimens attributed to the same species or living relatives. Abbreviations: ci, capital incisure; dt, dorsal tubercle; hts, humerotricipital sulcus; lc, lateral hypotarsal crest; le, lateral edge of the metatarsi IV; lf, lateral proximal vascular foramen; mf, medial proximal vascular foramen; pli, pit for ligament insertion; ptr, posterior trochlear ridge; sts, scapulotricipital sulcus; tf, tricipital fossa; tII, trochlea metatarsi II; tIII, trochlea metatarsi III; tIV, trochlea metatarsi IV; ts, transverse sulcus.