Hildoceratoidea

Hildoceratoidea
Temporal range: Early—Middle Jurassic, Pliensbachian–Bajocian
Harpoceras exaratum
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: †Ammonoidea
Order: †Ammonitida
Suborder: †Ammonitina
Superfamily: †Hildoceratoidea
Hyatt, 1867
Families

Hildoceratoidea, formerly Hildoceratacaea, is a superfamily of compressed or planulate ammonites, some tending to develop acute outer rims; generally with arcuate or sigmoidal ribs. Aptichus were found in place are double-valved.

Hildoceratoidea is an upper Lower to lower Middle Jurassic group belonging to the Ammonitina that unites the Hildoceratidae, Hammatoceratidae, Graphoceratidae, and Sonniniidae. In some taxonomies the name Phymatoceratidae is substituted for the Hammatoceratidae

Hildoceratidae, which is the ancestral family, is derived from the Acanthopleuroceratinae, a subfamily in the Eoderoceratoidean family, Polyorphitidae. The Stephanoceratoidea, Perisphinctoidea, and Haploceratoidea have their source in the Hammatoceratidae which is derived from the Hildoceratidae.

Approximate timeline of Hildoceratoidea families with their evolutionary relationships.

References

  1. ↑ "Paleobiology Database - Hildoceratoidea". Retrieved 2017-10-19.
  2. ↑ Kovács, Z.; Géczy, B. (2008). "Upper Toarcian – Middle Aalenian (Jurassic) Erycitinae SPATH (Ammonitina) from the Gerecse Mts, Hungary" (PDF). 125th Anniversary of the Department of Palaeontology at Budapest University – A Jubilee Volume Hantkeniana. 6: 57–108. Archived from the original (PDF) on 2011-07-16. Retrieved 2010-11-25.
  3. 1 2 3 Arkell et al., Treatise on Invertebrate Paleontology, Part L Ammonoidea, (1956)
  4. ↑ Taxonomicon (Hildocerataceae)|