Fig. 2From: Diet of Mesozoic toothed birds (Longipterygidae) inferredĀ from quantitative analysis of extant avian diet proxiesMeasurements taken to calculate mechanical advantage and functional indices in this study. All are mapped onto the outline of a skull of Falco peregrinus. Measurements are of anterior jaw-opening mechanical advantage AMA (A), posterior jaw-opening mechanical advantage PMA (B), jaw-opening mechanical advantage OMA (C), relative articular offset AO (D), relative maximum cranial height MCH (E), and relative average cranial height ACH (F). Outlevers are drawn in blue, inlevers in red, and skull length in green. Lines of action of m. adductor mandibulae (A, B) and attachment of m. depressor mandibulae (C) are indicated by a dashed pink line. The crosshatched region in F indicates an area measurement. Line drawing based on specimen CM S-14309Back to article page