Anarcestina

The Ancarcestina is a suborder of primitive ammonoids that lived during the Devonian, named by Miller & Furnish, 1954, with ventral retrochoanitic siphuncles (septal necks point to the rear, toward the apex) and goniatic sutures that vary in the number of lobes. The more primitive have 3 or 4 lobes, the more advanced have auxiliary and/or advantitious lobes in addition.

The Anarcestina is included in the Agonititida, sometimes referred to as the Anarcestida, along with the Agoniatitina, Gephuroceratina, and Pharciceratina, and includes the Anarcestaceae and Prolobitaceae.