''Costigymnites'' is an extinct genus of cephalopods belonging to the

Ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

subclass that lived in lower

Anisian In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from million years ago until million years ago. The Anisian Age succeeds the Olenekian Age (part of the Lower Triassic Ep ...

(

Bithynian Bithynia (; Koine Greek: , ''Bithynía'') was an ancient region, kingdom and Roman province in the northwest of Asia Minor (present-day Turkey), adjoining the Sea of Marmara, the Bosporus, and the Black Sea. It bordered Mysia to the southwest, Pa ...

, Ismidicus zone) in what is now

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

. The only known species is ''C. asiaticus'', which is known from 2 incomplete specimens.KRYSTYN, Leopold; TATZREITER, Franz. Middle Triassic ammonoids from Aghdarband (NE-Iran) and their paleobiogeographical significance. Abhandlungen der Geologischen Bundesanstalt, 1991, 38: 139-163.

References

Gymnitidae Ceratitida genera Middle Triassic ammonites Ammonites of Asia {{Ceratitida-stub