Hildoceras

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Hildoceras
Temporal range: Toarcian [1]
Fosil Hildoceras.jpg
Hildoceras sp.
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Family: Hildoceratidae
Subfamily: Hildoceratinae
Genus: Hildoceras
Hyatt, 1876
Species
  • See text
Recreation of Hildoceras Hildoceras NT.jpg
Recreation of Hildoceras
Hildoceras species from the Toarcian Bifrons Zone of the Gerecse Mts, Hungary. Collection Eotvos University, Dep. Palaeontology, Budapest. Hildoceras-fajok a Gerecse hegysegbol.tif
Hildoceras species from the Toarcian Bifrons Zone of the Gerecse Mts, Hungary. Collection Eötvös University, Dep. Palaeontology, Budapest.

Hildoceras is a genus of ammonite from the Jurassic [1] period in the family Hildoceratidae. The shells are characterized by a narrow discoidal evolute shape, keeled venter, concave ribs along the outer flanks, and a shallow spiral groove running along smooth inner flanks. Whorls slightly overlap, cross sections are compressed. The ventral keel is bordered on either side by a shallow groove. The genus was named by Alpheus Hyatt after Saint Hilda in 1876.

Contents

Hildoceras sp morphological and external structural characteristics Hildoceras spp.jpg
Hildoceras sp morphological and external structural characteristics

Distribution

Jurassic of Bulgaria, France, Germany, Hungary, Italy, Japan, Luxembourg, Serbia and Montenegro, Spain, the United Kingdom and Iran. [2] [3]

Species

Related Research Articles

The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 184.2 Ma and 174.7 ±0.8 Ma. It follows the Pliensbachian and is followed by the Aalenian.

<i>Stephanoceras</i> Genus of molluscs (fossil)

Stephanoceras is an extinct genus of Stephanoceratoid ammonite which lived during the Bajocian. It is the type genus of the family Stephanoceratidae.

<i>Arietites</i> Genus of molluscs (fossil)

Arietites is a genus of massive, giant evolute, psiloceratacean ammonites in the family Arietitidae in which whorls are subquadrate and transversely ribbed and low keels in triplicate, separated by a pair of longitudinal grooves, run along the venter. Fossils are known world wide from the lower Sinemurian stage of the Lower Jurassic. Safari Ltd made an Arietites bucklandi figurine in 2014.

<i>Arnioceras</i> Genus of molluscs (fossil)

Arnioceras is an extinct genus of large, evolute, discoidal ammonite from the Lower Jurassic. The shell is normally coiled so that all whorls are exposed. Sides bear strong sharp ribs that are straight until reaching the ventrolateral edge where they swing forward and fade. The rim (venter) is keeled and free of grooves.

Berniceras is an extinct ammonite genus from the order Ammonitida that lived during the early Oxfordian stage of the Late Jurassic. Berniceras is included in the ammonite family, Oppeliidae.

Otoites is the type genus of the ammonite family Otoitidae that live during the Middle Jurassic.

Oecoptychius is an extinct genus of fossil ammonite cephalopods. The species lived during the Middle Jurassic.

<i>Normannites</i>

Normannites is a strongly ribbed evolute Middle Jurassic genus of ammonite included in the stephanoceratoid family Stephanoceratidae.

Haplopleuroceras is a Middle Jurassic ammonite and likely member of the Hildoceratacean family Sonniniidae with which it shares the same sort of ribbing.

<i>Psiloceras</i> Genus of molluscs (fossil)

Psiloceras is an extinct genus of ammonite. Psiloceras is among the earliest known Jurassic ammonites, and the appearance of the earliest Psiloceras species form the definition for the base of the Jurassic. Unlike most earlier ammonites, which had complex shell shapes and ornamentation, Psiloceras had a smooth shell.

<i>Distichoceras</i> Extinct family of molluscs

Distichoceras is a member of the Haploceratacean family, Oppeliidae, and type genus for the subfamily Distichoceratinae, found in upper Middle and lower Upper Jurassic sediments in Europe, Algeria, India, and Madagascar. The shell is essentially evolute and compressed with the outer flanks converging on a narrow, keeled venter; inner flanks which may be feebly ribbed, are separated from outer by a shallow spiral groove or band. Ribs on outer flanks end on or are looped to tall clavi that line the venter, standing above the keel.

<i>Hecticoceras</i> Genus of molluscs (fossil)

Hecticoceras is an ammonite genus belonging to the haploceratoid family Oppeliidae, that lived during the Middle and Late Jurassic, from the Callovian. Hecticoceras may be seen as a series of some nine subgenera, beginning with the lower Callovian H. (Hecticoceras) and H. (Hecticoceratoides) and ending with the lower Oxfordian H. (Pseudobrightia) and H. (Eochetoceras). Hecticocerassensu lato and Prohecticoceras from the underlying Bathonian form the oppeliid subfamily, Hecticoceratinae.

<i>Calliphylloceras</i> Genus of ammonites

Calliphylloceras is an ammonite belonging to the Phylloceratidae.

<i>Lytoceras</i> Genus of molluscs (fossil)

Lytoceras is an ammonite genus that was extant during most of the Jurassic and Cretaceous periods, and is the type genus for the family Lytoceratidae. These cephalopods were fast-moving nektonic carnivores.

<i>Hildoceras bifrons</i> Extinct species of ammonite

Hildoceras bifrons is an extinct species of ammonite in the family Hildoceratidae. It dates from about 175 million years ago in the Early Jurassic when it was both widespread and common. Fossils have been found in North Africa and Europe, including several regions of England.

<i>Harpoceras</i> Genus of molluscs (fossil)

Harpoceras is an extinct genus of ammonite belonging to the family Hildoceratidae. These cephalopods existed in the Jurassic period, during the Toarcian age from the Falciferum zone to the Commune subzone of the Bifrons zone. They were fast-moving nektonic carnivores.

Ochetoceras is a genus of ammonites, belonging to the Oppeliidae, that lived during the Late Jurassic from the early Oxfordian to the early Tithonian, and type for the subfamily Ochetoceratinae.

<i>Hammatoceras</i> Genus of molluscs (fossil)

Hammatoceras is a genus of ammonites belonging to the family Hammatoceratidae which lived during the Toarcian stage of the Early/Lower Jurassic between about 184 and 175 million year ago.

<i>Cleviceras</i> Genus of molluscs (fossil)

Cleviceras is an extinct genus of cephalopod belonging to the family Hildoceratidae. These cephalopods existed in the Jurassic period, during Toarcian and possibly even uppermost Pliensbachian age. Sometimes, it is considered to be a synonym of Eleganticeras.

Parahildaites is genus of ammonites that lived during the lower Toarcian stage of early Jurassic, during Bifrons zone. It differs from Hildaites and Hildoceras by having smooth shell after reaching 4 cm in diameter. There is no spiral groove and on early whorls, there can be sigmoidal ribs or striae. Strong keel is bordered by flat areas or slight sulci. Its fossils were found in Saudi Arabia and Madagascar.

References

Notes
  1. 1 2 Sepkoski, Jack (2002). "Sepkoski's Online Genus Database" . Retrieved 2014-05-28.
  2. "Paleobiology Database - Hildoceras" . Retrieved 17 December 2021.[ permanent dead link ]
  3. Seyed-Emami, Kazem, et al. "Toarcian and Aalenian (Jurassic) ammonites from the Shemshak Formation of the Jajarm area (eastern Alborz, Iran)." Paläontologische Zeitschrift 79.3 (2005): 349-369.
Bibliography