Pseudobrevicoceras
Encyclopedia
Pseudobrevicoceras is an extinct nautilitoid
cephalopod genus in the order Oncocerida
. The familial position is undetermined.
Externally Pseudobrevicoceras resembles Brevicoceras
, an oncocerid in the Brevicoceratidae
, in having a curved, expanded, breviconic phragmocone
with straight, transverse suture
s.
Nautilitoidea
The Nautilitoidea is a superoder within the subclass Nautiloidea, comprizing the phylogenetically related Nautilida, Oncocerida, and Tarphycerida....
cephalopod genus in the order Oncocerida
Oncocerida
The Oncocerida comprise a diverse group of generally small nautiloid cephalopods known from the Middle Ordovician to the Mississippian ,in which the connecting rings are thin and siphuncle segments are variably expanded...
. The familial position is undetermined.
Externally Pseudobrevicoceras resembles Brevicoceras
Brevicoceras
Brevicoceras is an extinct prehistoric nautiloid genus from the order Oncocerida with wide distribution in the Middle Devonian in Eastern North America, Russia and Morocco...
, an oncocerid in the Brevicoceratidae
Brevicoceratidae
The Brevicoceratidae, named by Flower in 1941, is a family of oncocerids that contains genera characterized by exogastric gyrocones, brevicones, and torticones that tend to develop vestigial actinosiphonate deposits and subtriangular transverse sections...
, in having a curved, expanded, breviconic phragmocone
Phragmocone
The phragmocone is the chambered portion of the shell of a cephalopod. It is divided by septa into camerae.In most nautiloids and ammonoids, the phragmocone is a long, straight, curved, or coiled structure, in which the camarae are linked by a siphuncle which determines buoyancy by means of gas...
with straight, transverse suture
Suture
Surgical suture is a medical device used to hold body tissues together after an injury or surgery. It generally consists of a needle with an attached length of thread. A number of different shapes, sizes, and thread materials have been developed over its millennia of history.-History:Through many...
s.