Rhabdiferoceras is an extinct orthocerid

Orthocerida

Orthocerida is an order of extinct nautiloid cephalopods also known as the Michelinocerda that lived from the Early Ordovician possibly to the Late Triassic . A fossil found in the Caucasus suggests they may even have survived until the Early Cretaceous...

 genus belonging to the Baltoceratidae

Baltoceratidae

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 .-Taxonomy:Baltoceratidae was...

 that lived in what would be North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 during the Cassinian

Cassinian

The Cassinian is the latest age of the Canadian Epoch when thought of temporally and the uppermost stage of the Canadian Series when thought of stratigraphically...

 Stage at the end of the Early Ordovician

Ordovician

The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...

, existing for approximately two million years from about 474 -472 mya.

Taxonomy

Rhabdiferoceras was named by Flower (1964). Its type is Rhabdiferoceras annuliferum. It was assigned to Baltoceratidae

Baltoceratidae

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 .-Taxonomy:Baltoceratidae was...

by Flower (1964) and Hook and Flower (1977).

Morphology

Rhabdiferoceras is a rod-bearing baltoceratid with undulations on the dorsal side of the ventral siphuncular rod that correspond to the segments of the siphuncle. Septal necks are very short, connecting rings are layered and are slightly expanded and gently convex from the outside. The genotype, Rhadiferoceras annuliferum Flower is known only from sectioning a limestone block, presumed to be of Cassinian age from the Pogonip Group from the northern end of the Ely Springs Range, Nevada.. The siphuncle is rather large, in proportion, and slightly removed from the venter, considered a baltoceratid aspect.

We can only guess at what the animal may have been like or as to its habits. As an orthocerid it may have had 8 or 10 long arms or tentacles projecting from its head, as found in modern squid

Squid

Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...

s, belemnites, and indicated for Upper Ordovician Orthonybyoceras and Silurian Michelinoceras

Michelinoceras

Michelinoceras is the oldest known genus of the Michelinocerida, more commonly known as the Orthocerida, characterized by long, slender, nearly cylindrical orthocones with a circular cross section, long camerae, very long body chambers, and a central or near central tubular siphuncle free of...

.