original_query: What is the difference in the size of the tympanic cavity between lorisoids and lemurs?
query: What is the difference in the size of the tympanic cavity between lorisoids and lemurs?
answer: In lemurs, the tympanic cavity is expanded, leaving the ectotympanic ring free within the auditory bulla. In lorisoids, the tympanic cavity is smaller, and the ectotympanic ring is attached to the edge of the auditory bulla.  Lorisoids also have two accessory air spaces in the tympanic cavity that are absent in lemurs.