Fig. 6.

Osteology. Lateral (a) and ventral (b) view of the right os quadratum of Geospiza fortis, and lateral (c) and ventral (d) view of the right os quadratum of Padda oryzivora. Note that the processus orbitalis is somewhat more robust in G. fortis, but that the ossa quadrata of these species are overall very similar. cond.caud., condylus caudalis; cond.lat., condylus lateralis; cond.med., condylus medialis; cond.proot.qd., condylus prooticus quadrati; cond.pter., condylus pterygoidei; cond.qd.jug., condylus quadrati jugalis; cond.sq.qd., condylus squamosus quadrati; corp.qd., corpus quadrati; proc.mand.qd., processus mandibularis quadrati; proc.orb.qd., processus orbitalis quadrati; proc.ot.qd., processus oticus quadrati; sp.ps.temp., spina pseudotemporalis; tub.add.mand., tuberculum adductor mandibulae.