CT reconstruction of the petrosals of the sirenian from Chambi and Prorastomus.

ABC: CBI-1-542. DEF: Prorastomus (BMNH 44897). AD: ventral view, BC: ventrolateral view, CF: dorsal view. Scale bar = 5mm. Broken areas are in grey on drawings. Prorastomus was mirrored for the purpose of comparison. Ac.ant.: foramen acusticum anterius; A.crib.med.: area cribrosa media; Ac.post.: foramen acusticum posterius; Acq.vest.: acqueductus vestibuli; Alisph.art.: alisphenoid articulation facet; Ant.crus: attachment area for the anterior crus of the tympanic; Can.coc.: canaliculus cochleae; Com.sup.fac.: commissura suprafacialis; Fac.f.: facial foramen; Fac.s.: facial sulcus; Fal.notch: fallopian notch; F.coc.: fenestra cochleae; Fos.ten.tymp.: fossa tensor tympani; F.vest.: fenestra vestibuli; Hiat.fal.: hiatus fallopi; Pars.coc.: pars cochlearis; Pars.mast.: pars mastoidea; Post.crus: attachment area for the posterior crus of the tympanic; Psdtymp.f.: pseudotympanic foramen; Rec.ept.: recessus epitympanicus; Sept.meta.: Septum metacochleae; S.fac.f.: secondary facial foramen; Sing.f.: singular foramen; Sin.pet.inf.: sinus petrosus inferius; Sin.pet.sup.: sinus petrosus superius; Stap.mu.fos.: stapedial muscle fossa; Teg.tymp.: tegmen tympani; Teg.proc. : tegmen process; Tract.spir.f.: tractus spiralis foraminosus; Tymp.hyal.pr.: tympanohyal process; Utr.f.: utricular foramen.