Fig 12.

Perinatal Alligator mississippiensis (OUVC 10606) shown in A) left lateral view with the braincase rendered in red and B) with the braincase isolated and the prootic rendered in red and the supraoccipital rendered in green. Isolated prootic and supraoccipital with endosseous labyrinth C) in left lateral view and D) with the left prootic rendered transparent. Isolated prootic and supraoccipital E) in dorsal view and F) with the supraoccipital and left prootic rendered transparent. Labyrinth rendered in pink, intertympanic diverticulum rendered in blue. cssc,caudal semicircular canal; lag, lagena; lssc, lateral semicircular canal; pado _otd, communicating ostia between parietal diverticula and intertympanic diverticulum; pil, osseous pillar; pr, prootic; PTsf, fossa for pharyngotympanic sinus; ptso _itd, communicating ostium between pharyngotympanic sinus and intertympanic diverticulum; so, supraoccipital.