Kionoceras
Encyclopedia
Kionoceras is an extinct nautiloid cephalopod genus included in the orthocerid
family Kionoceratidae
with scattered worldwide distribution from the Middle Ordovician
to the Lower Permian
. Kionoceratids are orthocerids with prominent longitudinal ornamentation on their shells, sometimes augmented by secondary trasverse ornamenttion. Orthocerids are, of course, prehistoric nautiloides with generally straight and elongate shells, mostly with central or subcentral siphuncles. (Sweet 1964)
Kionoceras is characterized by long, slender to rapidly expanding, shells with prominent longitudinal ribs separated by concave interspaces and, often, less conspicuous longitudinal and transverse lirae and striae. The siphuncle is central or subcentral, generally orthochoanitic; empty in Silurian type-species and in most from the Ordovician, but with annulosiphonate deposits in some from the Silurian and later.
Kionoceras is found in North America, Europe, Asia, and Australia. The type-species Kionocers doricum comes from the Middle Silurian of Central Europe
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...
family Kionoceratidae
Kionoceratidae
Kionoceratidae is a family in the Orthocerida, proposed by Hyatt in 1900 for genera characterized by prominent ornamentation in the form of longitudinal ribs, ridges, or lirae, or combinations thereof, sometimes with similar transverse ornament or faint transverse annulations.When Kionoceratidae...
with scattered worldwide distribution from the Middle 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...
to the Lower Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
. Kionoceratids are orthocerids with prominent longitudinal ornamentation on their shells, sometimes augmented by secondary trasverse ornamenttion. Orthocerids are, of course, prehistoric nautiloides with generally straight and elongate shells, mostly with central or subcentral siphuncles. (Sweet 1964)
Kionoceras is characterized by long, slender to rapidly expanding, shells with prominent longitudinal ribs separated by concave interspaces and, often, less conspicuous longitudinal and transverse lirae and striae. The siphuncle is central or subcentral, generally orthochoanitic; empty in Silurian type-species and in most from the Ordovician, but with annulosiphonate deposits in some from the Silurian and later.
Kionoceras is found in North America, Europe, Asia, and Australia. The type-species Kionocers doricum comes from the Middle Silurian of Central Europe