CT reconstruction of the petrosals of the sirenian from Chambi and <i>Prorastomus</i>.

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