Siberionautilidae
Encyclopedia
Siberionautilidae is a family in the nautilid
superfamily Clydonautilaceae that contains only the genus Siberionautilus, which comes from the Upper Triassic (Carnian
) of Siberia, Russia.
The family, and genus, are characterized by an involute, globular shell covered by fine radial ribs, with flattened flanks that converge toward a rounded venter, distinct umbilicus with rounded shoulders, differentiated suture, and central siphuncle. The suture is goniatitic with the ventral or median saddle of the Clydonautilidae
, subdivided so as to have a deep finger-like median ventral lobe bracketed by finder-like secondary lobes and saddles, and on either side, a large claw-like asymmetric lateral lobe.
Like Gonionautilus
, Siberionautilus is derived from the Clydonautilidae, only the genus is unspecified. As with Gonionautilus and more advanced Clydonautilidae, Siberionautilus is one of a handful of nautilids that have goniatitic sutures as found in primitive ammonoids.
Nautilida
The Nautilida constitute a large and diverse order of generally coiled nautiloid cephalopods that began in the mid Paleozoic and continues to the present with a single family, the Nautilidae which includes two genera, Nautilus and Allonautilus, with six species...
superfamily Clydonautilaceae that contains only the genus Siberionautilus, which comes from the Upper Triassic (Carnian
Carnian
The Carnian is the lowermost stage of the Upper Triassic series . It lasted from about 228.7 till 216.5 million years ago . The Carnian is preceded by the Ladinian and is followed by the Norian...
) of Siberia, Russia.
The family, and genus, are characterized by an involute, globular shell covered by fine radial ribs, with flattened flanks that converge toward a rounded venter, distinct umbilicus with rounded shoulders, differentiated suture, and central siphuncle. The suture is goniatitic with the ventral or median saddle of the Clydonautilidae
Clydonautilidae
The Clydonautilidae are Middle and Upper Triassic nautiloid cephalopods, which are derivatives of the clydonautlicean family Liroceratidae, that have generally smooth, involute, globular to compressed shells, characterized by a suture with prominent lobes and saddles...
, subdivided so as to have a deep finger-like median ventral lobe bracketed by finder-like secondary lobes and saddles, and on either side, a large claw-like asymmetric lateral lobe.
Like Gonionautilus
Gonionautilidae
Gonionautilidae is a family in the nautilid superfamily Clydonautiliaceae that contains only the genus Gonionautilus, known from the Upper Triassic of Europe and North America....
, Siberionautilus is derived from the Clydonautilidae, only the genus is unspecified. As with Gonionautilus and more advanced Clydonautilidae, Siberionautilus is one of a handful of nautilids that have goniatitic sutures as found in primitive ammonoids.
References
- Bernhard Kummel, 1964. Nautiloidea -Nautilida; Treatise on Invertebrate Paleontology, Part K. Geol Soc of America and Univ of Kansas press, R.C. Moore (ed)