Paraloxoceras
Encyclopedia
Paraloxoceras is a straight shelled, orthoconic, nautiloid cephalopod, now extinct, that lived during the Early Carboniferous
. Fossils have been found in Europe and central Asia; the type, P. konincki, named by Flower, came from Belgium.
The shell of Paraloxoceras is slightly depressed, with straight sutures. Septa are fairly close spaced. The siphuncle
is located about half way between the center and the venter with segments that are broadly expanded into the chambers. As typical for the subfamily, Paraloxoceras contains organic endosiphuncular deposits penetrated by a canal system similar to that found in actinocerids
but differs in the having a protoconch characteristic of the pseudorthocerids
. During grow of the animal the shell expands dorsally with the distance between the dorsum and siphuncle increasing while the separation between the venter and siphuncle remains at a more or less constant.
Related genera include Pseudactinoceras
, Macroloxoceras
, and Eusthenoceras
Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
. Fossils have been found in Europe and central Asia; the type, P. konincki, named by Flower, came from Belgium.
The shell of Paraloxoceras is slightly depressed, with straight sutures. Septa are fairly close spaced. The siphuncle
Siphuncle
The siphuncle is a strand of tissue passing longitudinally through the shell of a cephalopod mollusk. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the living nautiluses, cuttlefish, and Spirula...
is located about half way between the center and the venter with segments that are broadly expanded into the chambers. As typical for the subfamily, Paraloxoceras contains organic endosiphuncular deposits penetrated by a canal system similar to that found in actinocerids
Actinocerida
The Actinocerida comprise an order of generally straight, medium to large cephalopods that lived during the early and middle Paleozoic, distinguished by a siphuncle composed of expanded segments that extend into the adjacent chambers, in which deposits formed within contain a system of radial...
but differs in the having a protoconch characteristic of the pseudorthocerids
Pseudorthocerida
Pseudorthocerida are generally straight longiconic nautiloids with a subcentral to marginal cyrtochoanitic siphuncle composed of variably expanded segments which may contain internal deposits that may develop into a continuous parietal lining.. Cameral deposits are common and concentrated ventrally...
. During grow of the animal the shell expands dorsally with the distance between the dorsum and siphuncle increasing while the separation between the venter and siphuncle remains at a more or less constant.
Related genera include Pseudactinoceras
Pseudactinoceras
Pseudactinoceras is an extinct nautiloid cephalopod included in the order Pseudorthocerida and the namesake of the family Pseudactinoceratidae .-Description:...
, Macroloxoceras
Macroloxoceras
Macroloxoceras is a large pseuorthocerid from the upper Devonian of Central Colorado and Southern New Mexico with features resembling those found inactinocerids....
, and Eusthenoceras