Medlicottiinae
Encyclopedia
The Medlicottiinae a subfamily of the Medlicottiidae
, a family of ammonoid cephalopods included in the Prolecanitida
, characterized by having discoidal to thinly lenticular shells with a retuse (grooved) venter and sutures with bifid auxiliary lobes.
The Medlicottiinae includes, by general consensus the following five genera: Artinskia, Eumedlicottia, Medlicottia, Neogeoceras, and Syrdenites. Of these only Artinskia and Medlicottia, included in the Medlicottinae in the Treatise (Miller, Furnish, and Schindewolf, 1957) remain. Episageceras, Propinacoceras, and Sicanites, then included, have become type genera respectively for the Episageceratinae
, Propinacoceratinae, and Sicanitinae.
Artinskia is the ancestral form, thought to be derived from Uddenoceras (Uddenitinae
), which gave rise to the type genus Medlicottiia. Medilicottia then gave rise to Eumedlicottia and Neogeoceras. The derivation of Syrdenites is uncertain.
Medlicottiidae
Medlicottiidae is a family of ammonoid cephalopods belonging to the Prolecanitida, known from the Upper Carboniferous to the Early Triassic.-Characteristics:...
, a family of ammonoid cephalopods included in the Prolecanitida
Prolecanitida
The Prolecanitida are 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...
, characterized by having discoidal to thinly lenticular shells with a retuse (grooved) venter and sutures with bifid auxiliary lobes.
The Medlicottiinae includes, by general consensus the following five genera: Artinskia, Eumedlicottia, Medlicottia, Neogeoceras, and Syrdenites. Of these only Artinskia and Medlicottia, included in the Medlicottinae in the Treatise (Miller, Furnish, and Schindewolf, 1957) remain. Episageceras, Propinacoceras, and Sicanites, then included, have become type genera respectively for the Episageceratinae
Episageceratinae
Episageceratinae is a subfamily of the Medlicottiidae, a family of prolecanitid ammonites. The Episageceratinae, proposed by Ruzhencev, 1956, is based on the genus Episageceras previously included in the subfamily Medlicottiinae and lived during Late Permian and Early Triassic times.So far only...
, Propinacoceratinae, and Sicanitinae.
Artinskia is the ancestral form, thought to be derived from Uddenoceras (Uddenitinae
Uddenitinae
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 transistional between the ancestral Pronoritidae and the more more traditional...
), which gave rise to the type genus Medlicottiia. Medilicottia then gave rise to Eumedlicottia and Neogeoceras. The derivation of Syrdenites is uncertain.
References
- Miller, Furnish, and Schindewolf, 1957. Paleozoic Ammonoidea (Prolecanitina); Treatise on Invertebrate Paleontology, Part L,(Ammonoidea). Geol Soc of America and Univ Kansas Press.