Fig. 4 in New Miocene sulid birds from Peru and considerations on their Neogene fossil record in the Eastern Pacific Ocean

Fig. 4. Sulid bird Ramphastosula aguirrei sp. nov. from Poza Negra, Sacaco Sur (Peru), Pisco Formation, Late Miocene. A Holotype MUSM 665. Skull in lateral (A1), posterior (A2), dorsal (A3), and ventral (A4) views. Left quadrate in (A5) anterior and (A6) posterior views. B. Section of rostrum at its midlength showing differences in the outline of Ramphastosula and other sulids. C–E. Comparison of the ear region in ventral view in the Peruvian booby Sula variegata DPV AM P8 (C) from Isla Lobos de Afuera, Lambayaque (Peru), Recent; R. ramirezi MUSM 264 (D) from Poza Roja, Sacaco Sur (Peru), Messinian (Late Miocene); and R. aguirrei MUSM 665 (E) from Poza Negra, Sacaco Sur (Peru), Messinian (Late Miocene).