Holcodiscus

Holcodiscus is an extinct ammonite genus placed in the family Holcodiscidae. Species in this genus were fast-moving nektonic carnivores.^[2] The type species of the genus is Ammonites caillaudianus.^[2]

Holcodiscus Temporal range: Cretaceous[1][2] 130.0–84.9 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Fossil shell of Holcodiscus fallax from Alpes-de-Haute-Provence, on display at Galerie de paléontologie et d'anatomie comparée in Paris
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	†Ammonoidea
Order:	†Ammonitida
Family:	†Holcodiscidae
Genus:	†Holcodiscus Uhlig, 1882

Description

Circular to rectangular whorl section; fine, low, straight or flexuous simple or branched ribs, periodically truncated by thin, high, enlarged ribs bearing lateral and ventrolateral tubercles; inner whorls tending to have depressed whorl section and to resemble Olcostephanus.^[3]

Species

Source:^[2]

• Holcodiscus caillaudianus d'Orbigny 1850
• Holcodiscus camelinus d'Orbigny 1850
• Holcodiscus hauthali Paulcke 1907
• Holcodiscus tenuistriatus Paulcke 1907

Distribution

Fossils of species within this genus have been found in the Cretaceous sediments of Austria, Bulgaria, Chile, Colombia, Czech Republic, Slovakia, France, Italy, Morocco, Spain and Russia.^[2]

Gallery

• 
  Holcodiscus mediocostatus Tzankov, 1935, Barremian, Razgrad, Cr1 1716 (Coll. V. Tzankov) at the Sofia University Museum of Paleontology and Historical Geology