Right petrosal Type A (Protolambda) after Wible (1990) showing reconstruction of vasculature. Abbreviations: ac aqueductus cochleae; adm arteria diploetica magna; cev capsuloparietal emissary vein; cp crista parotica; ctpp caudal tympanic process of petrosal; er epitympanic recess; fc fenestra cochleae; fi fossa incudis; fs facial sulcus; fv fenestra vestibuli; hF, hiatus Fallopii; If, lateral flange of petrosal; lhv lateral head vein; It, lateral trough of petrosal; me mastoid exposure; mp mastoid process; pc prootic canal; pcv vein ofprootic canal; pff primary facial foramen; pp paroccipital process; pr promontorium; ri ramus inferior of stapedial artery; rs ramus superior of stapedial artery; rtpp rostral tympanic process of petrosal; sa stapedial artery; sev sphenoparietal emissary vein; sf stapedius fossa; sff secondary facial foramen; sips sulcus for inferior petrosal sinus; spd sulcus for perilymphatic duct; vdm vena diploetica magna.

 
 
  Part of: Williamson TE, Brusatte SL, Wilson GP (2014) The origin and early evolution of metatherian mammals: the Cretaceous record. ZooKeys 465: 1-76. https://doi.org/10.3897/zookeys.465.8178