Double ended arrows represent emergent confluences between diverticula and between the adjacent sinus systems. Ontogenetic stages are A. Day 0 (~30mm DSL), B. ~10 months (~50mm DSL), C. yearling to subadult (100–300mm DSL), and D. adult (>300mm DSL). ARd, articular diverticulum; BOd, basioccipital diverticulum; BSd, basisphenoid diverticulum; ETr, recessus epitubaricum; IFd, infundibular diverticulum; ITd, intertympanic diverticulum; MPs, median pharyngeal sinus; OTd, otoccipital diverticulum; PAd, parietal diverticulum; PRd, prootic diverticulum; PTd, pterygoid diverticulum; PTs, pharyngotympanic sinus; PTt, pharyngotympanic tube; QUd, quadrate diverticulum; Sph, siphonium; Tymp, tympanum.