was named by Marsh (1877)
[Marsh's original type includes distal and proximal fragments of a right tarsometatarsal probably belonging to separate individuals; the distal end was selected as the lectotype by Martin and Tate 1976 (p. 37)
see also Shufeldt 1915]. Its type specimen is YPM 1465, a limb element (distal end of right tarsometatarsus), and it is a 3D body fossil. Its type locality is Baptornis advenus type locality
, which is in a Coniacian offshore chalk in the Niobrara Formation of Kansas.