• Webster's Revised Unabridged Dictionary
    • n Opisthotic (Anat) The inferior and posterior of the three elements forming the periotic bone.
    • ***
Century Dictionary and Cyclopedia
    • opisthotic Posterior and otic; of or pertaining to the opisthotic: correlated with epiotic, proötic, and pterotic. See otic.
    • n opisthotic The postero-inferior petrosal bone; one of the otic elements, the posterior and inferior ossification of the periotic capsule, which contains the essential auditory apparatus, forming a part of the petrosal or petromastoid bone. See cuts under Crocodilia and Esox.
    • ***


Webster's Revised Unabridged Dictionary
Gr. 'o`pisqen behind + , , ear


In literature:

The posterior wall of the otic capsule we have designated opisthotic in the figure.
"A New Order of Fishlike Amphibia From the Pennsylvanian of Kansas" by Theodore H. Eaton
Parietal bones separated by the supra-occipital; prootic and exoccipital separated by the enlarged opisthotic.
"Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 6" by Various
Here the opisthotic bone appears in the occipital region, as in the adult Chelonian.
"Encyclopaedia Britannica, 11th Edition, Volume 3, Slice 7" by Various
Opisthotic-exoccipital spur well-developed; epiplastral callosity, when present, not covering entire surface.
"North American Recent Soft-shelled Turtles (Family Trionychidae)" by Robert G. Webb