• Corpus ID: 62885928

Connecting ring structure and its significance for classification of the orthoceratid cephalopods

@article{Mutvei2002ConnectingRS,
  title={Connecting ring structure and its significance for classification of the orthoceratid cephalopods},
  author={Harry Mutvei},
  journal={Acta Palaeontologica Polonica},
  year={2002},
  volume={47}
}
  • H. Mutvei
  • Published 2002
  • Geology
  • Acta Palaeontologica Polonica
The connecting ring in orthoceratids is composed of two calcified layers: an outer spherulitic-prismatic and an inner calcified-perforate. The spherulitic-prismatic layer is a direct continuation of that layer in the septal neck, whereas the calcified-perforate layer is a structurally modified continuation of the nacreous layer of the septal neck. The latter layer is traversed by numerous pores which are oriented either transversally to the siphuncular surface, or have a somewhat irregularly… 

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Abstract The calciosiphonate type of the connecting ring was probably present in the oldest known nautiloid cephalopods, plectronocerids, from the Late Cambrian. This type also occurs in the

Siphuncular structure in Silurian discosorid and ascocerid nautiloids (Cephalopoda) from Gotland, Sweden: implications for interpretation of mode of life and phylogeny

The connecting ring structure is studied in the discosorids Phragmoceras and Trimeroceras, as well as in the ascocerid Choanoceras. These taxa have the Nautilus type of connecting rings, composed of

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Abstract:  The siphuncular structure is described in two Silurian taxa, Boionautilus tyrannus and Cumingsoceras complanatus, currently placed in the Tarpycerida. Tarphycerids have the Nautilus type

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Each septum of the phragmocone in the Jurassic belemnitid Magateuthis is composed of a thick, lamello-fibrillar, nacreous layer and a thin, chitinous layer, here termed the additional chitinous

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The connecting ring in the Recent Nautilus is composed of two layers: a fibrous, organic inner layer, and a porous, spherulitic-prismatic outer layer. The organic layer is an uncalcified continuation

LATE CAMBRIAN PLECTRONOCERID NAUTILOIDS AND THEIR ROLE IN CEPHALOPOD EVOLUTION

Abstract:  Numerous plectronocerid nautiloids appear in the Upper Cambrian of China. We have restudied their siphuncular structure, first described some 20 years ago. The siphuncle is characterized

Characterization of two new superorders Nautilosiphonata and Calciosiphonata and a new order Cyrtocerinida of the subclass Nautiloidea; siphuncular structure in the Ordovician nautiloid Bathmoceras (Cephalopoda)

The structure of the siphuncular ridges in Bathmoceras is compared with that of the actinosiphonate lamellae in the Silurian oncocerid nautiloid Octamerella.

The size of the siphuncle in cephalopod evolution

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Characterization of nautiloid orders Ellesmerocerida, Oncocerida, Tarphycerida, Discosorida and Ascocerida: new superorder Multiceratoidea

On the basis of the presence of multiple muscle scars and the Nautilus type of connecting ring, the ellesmerocerids, oncocerIDS, discosorids and ascocerid orders are included in the new superorder Multiceratoidea, still unclear whether tarphycerids also belong to this superorder.

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