Eotripteroceras
Eotripteroceras is a smooth-shelled orthocerid from the middle Ordovician of the state of New York.
The shell of Eotripteroceras is a depressed orthocone with the underside flatter than the upper. The siphuncle is below the center -as viewed in horizontal orientation- and is cylindrical in form. Both siphuncle and chambers are empty.