Trisecphora is a genus of extinct predatory ocenebrinid murexes indigenous to the Miocene coastline of what is now Maryland, North Carolina, and Virginia from the Aquitanian epoch until their extinction near the end of the Serravallian epoch.
The word was originally used by Vitruvius to signify the projecture of a member or moulding of a column, and here refers to the distinctive "T-shaped" ribs that project from the shell.
Trisecphora is one of three daughter genera of the Oligocene to Miocene ecphora Ecphorosycon, the other two being Siphoecphora, and Chesathais.
Trisecphora and its sister genera diverged from Ecphorosycon during a speciation event during the Aquitanian epoch in the Chesapeake Bay.
Trisecphora, itself, would go extinct during the middle of the Serravallian when a warming event killed the last species of that genus and of Chesathais off, as well as extirpating Planecphora (which would survive until the Pliocene in Floridian coral reefs).