Clydonautilidae

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Clydonautilidae
Temporal range: M -U Triassic
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Nautiloidea
Order: Nautilida
Superfamily: Clydonautiloidea
Family: Clydonautilidae
Hyatt, 1900

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. The family is known to contain five genera, These are:

Of these only Styrionautilus is known from the Middle Triassic. The other four are so far restricted to the Upper Triassic.

The five genera in the Clydonautilidae form a sequence of increasing sutural complexity, beginning with Styrionautilus and ending with Clydonautilus. Styrionautilis, which has the simplest suture of the five, has a broad ventral saddle with a flat bottom and a gently curved lateral lobe. Clydonauatilus at the opposite extreme has a secondary ventral saddle within the ventral lobe modifying the primary ventral saddle and a deep, asymmetric lateral lobe. Callaionautilus, Cosmonautilus, and Proclydonautulus fall in between.

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Medlicottiidae is a family of ammonoid cephalopods belonging to the Prolecanitida, known from the Upper Carboniferous (Pennsylvanian) to the Early Triassic.

Ussurites is an extinct ammonoid cephalopod genus belonging to the suborder Phylloceratina and is included in the family Ussuritidae. Its range is restricted to the early Middle Triassic, (Anisian)

Prolecanitida is an order of extinct ammonoid cephalopods with discoidal to thinly lenticular shells with goniatitic or ceratitic sutures and which retained the simple retrochoanitic siphuncle with backward extending septal necks. As typical for ammonoids the siphuncle is along the ventral margin. Prolecanitids form a relatively small and stable order within the Ammonoidea with 43 named genera and about 1250 species, but with a long-ranging lineage of about 108 m.y. stretching from the Lower Carboniferous to the Triassic. Although not as diverse as their goniatitid contemporaries, the Prolecanatida provided the stock from which all later Mesozoic ammonoids were derived.

The Clydonautiloidea are a superfamily within the nautiloid order Nautilida characterized by smooth, generally globular, shells with nearly straight sutures, in early forms, but developing highly differentiated sutures in some later forms. Where known, the siphuncle tends to be central to subcentral.

Trigonoceratoidea Extinct superfamily of nautiloids

The Trigonoceratoidea are a superfamily within the Nautilida that ranged from the Devonian to the Triassic, thought to have contained the source for the Nautilaceae in which Nautilus is found.

Syringonautilidae is a family of Nautiloidea from the middle to late Triassic. Syringonautilidae comprise the last of the Trigonoceratoidea and are the source for the Nautilaceae which continued the Nautiloidea through the Mesozoic and into the Cenozoic right down to the recent. Syringonautilidae is a strictly Triassic family, derived early in the Triassic from the Grypoceratidae.

Grypoceratidae Extinct family of molluscs

Grypoceratidae is the longest-lived family of the Trigonoceratoidea, or of the near equivalent Centroceratina; members of the Nautilida from the Upper Paleozoic and Triassic.

The Centroceratidae is the ancestral family of the Trigonoceratoidea and of the equivalent Centroceratina; extinct shelled cephalopods belonging to the order Nautilida

The Naedyceras group comprises three similar and closely related openly coiled, gyroconic, genera within oncocerid family, Brevicoceratidae: Naedyceras, Gonionaedyceras, and Gyronaedyceras.

Gonionautilidae is a family in the nautilid superfamily Clydonautiliaceae that contains only the genus Gonionautilus, known from the Upper Triassic (Norian) of Europe and North America.

Siberionautilidae is a family in the nautilid superfamily Clydonautiloidea that contains only the genus Siberionautilus, which comes from the Upper Triassic (Carnian) of Siberia, Russia.

Holconautilus is a genus of nautiloids from the family Tainoceratidae and order Nautilida, named by Mojsisovics, 1902, and known from Upper Triassic sediments in Europe and E Indies (Timor). Its shell, evolute, discoidal, with simple coarse lateral ribbing; whorl section, subrectagular with a broadly arched venter.

The Uddenitinae a subfamily of the Medlicottiidae, a family of ammonoid cephalopods included in the Prolecanitida. The Uddenitinae, proposed by Miller and Furnish, and known from the Pennsylvanian and Lower Permian, are transitional between the ancestral Pronoritidae and the more traditional medlicottiids

Sturia is a genus of ceratitid ammonoids from the Lower Triassic with an ammonitic suture.

Cosmonautilus is a genus of cephalopods included in the nautilid family Clydonautilidae. Its shell is involute, with only the outer whorl exposed. Early whorls are with nodes on ventral shoulder, which disappear on the later growth staged. Later whorls are smooth.

Clydonautilus is a genus of nautiloids and type for the Clydonautilidae that has been found in the Upper Triassic of Europe, India, and Timor. Its type is C. noricus.

Proclydonautilus is a genus of nautiloids belonging to the Clydonautilidae known from the Upper Triassic of North America, Europe, and India.

Styrionautilus is a genus of nautiloids and first of the Clydonautilidae with a range extending from the Middle Triassic, Anisian to the Upper Triassic, Norian. Its fossils found in North America (Nevada), Europe, and Timor.

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