The Tarphycerida were the first of the coiled cephalopods, found in marine sediments from the Lower Ordovician (middle and upper Canad) to the Middle Devonian. Some, such as Aphetoceras and Estonioceras, are loosely coiled and gyroconic; others, such as Campbelloceras, Tarphyceras, and Trocholites, are tightly coiled, but evolute with all whorls showing. The body chamber of tarphycerids is typically long and tubular,[1] as much as half the length of the containing whorl in most, greater than in the Silurian Ophidioceratidae.
The Tarphycerida evolved from the elongated, compressed, exogastric Bassleroceratidae, probably Bassleroceras, around the end of the Gasconadian through forms like Aphetoceras. Close coiling developed rather quickly, and both gyroconic and evolute forms are found in the early middle Canadian.
Tarphycerids tend to uncoil in the late mature stage of their growth, indicating they settled into a benthic lifestyle as they became older. Younger, wholly coiled forms were probably more active, nektobenthic, certainly more maneuverable.
^Furnish and Glenister 1964; Nautiloidea - Tarphycerida; In the Treatise on Invertebrate Paleontology Vol K; Teichert and Moore, (eds) GSA and U of Kansas Press 1964
The Tarphycerida were the first of the coiled cephalopods, found in marine sediments from the Lower Ordovician (middle and upper Canad) to the Middle Devonian...
membership is somewhat variable between authors, but it usually includes Tarphycerida, Oncocerida, and Nautilida. All nautiloids have a large external shell...
Ellesmerocerida, Oncocerida, Discosorida, and Ascocerida. The order Tarphycerida was considered a potential member of the subclass, though their larger...
Oncocerida Order † Discosorida Order † Tarphycerida Order † Barrandeocerida A polyphyletic group now included in the Tarphycerida Order Nautilida Subclass † Bactritoidea...
Nautilida, Oncocerida, and Tarphycerida. The superorder has its roots in the Bassleroceratidae, the ancestral family of the Tarphycerida, sometimes included...
rings thicken in towardly as in both the Ellesmerocerida and primitive Tarphycerida. Bassleroceras is the type genus of the Bassleroceratidae which Furnish...
to the Tarphycerida, and to the family Estonioceratidae. It was found in Alaska. W.M Furnish & Brian F. Glenister, 1964. Nautiloidea-Tarphycerida. Treatise...
nautiloid cephalopods from the upper Caradocian of Estonia, assigned to the Tarphycerida. The type species is Vasalemmoceras tolerabile Stumbur, 1962. Jack Sepkoski...
intermediary between the ancestral Ellesmerocerida and the more advanced Tarphycerida and Oncocerida. The order, as originally defined, contains two families...
Aethoceras is a genus of Tarphycerida nautiloids included in the family Estonioceratidae for which the shell is a loosely coiled, gradually expanding dextral...
(Barrandeoceratid siphuncles are central - subcentral. Reassignment to the Tarphycerida from the Barrandeocerida is based on barrandeoceratid taxa being polyphyletic...
included in the Orthocerida rather than as originally perceived in the Tarphycerida. Rousseau H Flower, 1962. Notes on the Michelinoceratida. Memoir 10,...
lacks a cicatrix. The Lituitida, which were originally included in the Tarphycerida as the Lituitidae (Furnish and Glenister) have their beginnings in the...
inherited from their ellesmeroceratid ancestors, which were passed on to the Tarphycerida. Leonardoceras has a poorly preserved, narrow siphuncle, apparently with...
through Bassleroceras, by evolving and ever tightened curvature to the Tarphycerida and by a thinning of the connecting rings to the Graciloceratidae which...
included in the Tarphycerida as a number of derived families. Furnish and Glenister (1964) removed the Lituitidae to the Tarphycerida on the basis of...
Order Pseudorthocerida † Order Ascocerida † Order Endocerida † Order Tarphycerida † Order Oncocerida † Order Discosorida † Order Nautilida Order Orthocerida...
Furnish and Glenister (1964) placed Beekmanoceras in the Trocholitidae (Tarphycerida), interpreting the curvature to be ventral side convex, i.e. exogastastric...
Paleontology in the section on the Estonioceratidae, p K357-K359, included in the Chapter on the Tarphycerida by Furnish and Glenister starting with page K343....
Cummingsoceras is a genus of barrandeoceroids within the Tarphycerida, included in the family Uranoceratidae. Its shell is a rapidly expanding gyrocone...
shells, and fall into the orders Endocerida (with wide siphuncles) and Tarphycerida (with narrow siphuncles). By the mid Ordovician these orders are joined...
Global Information
