Baltoceratidae is an extinct family of orthoconic cephalopods belonging to the subclass Nautiloidea endemic to what would be Asia, Australia, Europe, North America, and South America during the Ordovician living from about 480–460 mya, existing for approximately 20 million years.

Further study of baltoceratid interiors, namely regarding the generally thin connecting rings and lack of siphuncular diaphragms, showed they are distinct from the typical ellesmerocerids and belong, as the ancestral group, to the Orthocerida where assigned by Kroger et al. (2007) [6] The Baltorceratidae are characterized by dominantly straight, slender, smooth shells[4] with a moderately large ventral siphuncle composed of orthochoanitic septal necks and thin connecting rings,[5] free of diaphragms and which in advanced forms becomes more central in position.

Septa are close spaced, resulting in short camerae and may form shallow ventral lobes.

Rod bearing forms gave rise to the Troedsonnellidae with early members, Buttsoceras and Tajaroceras found in the upper Cassinian.

[6] Furthermore, the Baltoceratidae are restricted to forms with a siphuncle that is tubular or slightly expanded within the chambers, excluding genera with a more ellesmeroceratid aspect in which connecting rings thicken inwardly, such as Amsleroceras, Cyptendoceras, and Rioceras .