Neocycloceras
Encyclopedia
Neocycloceras is an extinct nautiloid genus included in the Pseudorthocerida that lived during the Late Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...

 and Mississippian (early Carboniferous
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"...

). Neoclycloceras is characterized by a slender, generally circular shell with slightly oblique,sinuous surficial annulations. Its 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 have dorsal and ventral saddles and lateral lobes and become more oblique with age. Saddles point forward, lobes to the rear. Dorsal saddles are broad and low but the ventral ones are high and conspicuous. 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 between the center and venter and is nummuloidal, composed of rounded expanded segments, the inside of which contains a continuous laminar lining that is thickest in the middle of the segments and thinnest at the septal necks. Neocycloceras has been found in Pennsylvania in North America and in Morocco in north Africa.

See also

  • Nautiloid
    Nautiloid
    Nautiloids are a large and diverse group of marine cephalopods belonging to the subclass Nautiloidea that began in the Late Cambrian and are represented today by the living Nautilus. Nautiloids flourished during the early Paleozoic era, where they constituted the main predatory animals, and...

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