Uddenitinae
Encyclopedia
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
(U Carb
) and Lower Permian
, are transistional between the ancestral Pronoritidae and the more more traditional medlicottiids
Prouddenites, named by Miller, 1930, which is found in the Pennsylvanian of the south-central United States and the Urals, has a discoidal shell with a flattened venter and a suture with an unequally trifid first lateral lobe. It is Intermedate between Pronorites and Uddenites.
Uddenites, named by Böse, 1919, known from the Upper Pennsylvanian of Texas and the Urals, has a discoidal shell with a retuse (grooved) venter. The ventral portion of the first lateral lobe is intermediate in depth.
Diaxites, Ruzhentsev 1941, has the characteristic discoidal form but the ventral lobe is quite wide, still trifid.
Diaxites is Upper Pennsylvanian and Lower Permian in age.
Neouddenites, Ruzhentsev 1961, is similar to Uddenites, but later, coming from the Lower Permian.
Uddenoceras, named by Miller and Furnish, 1954, from the Upper Pennsylvanian of Texas and the Urals has a discoidal shell like Uddenites, but the ventro-lateral portion of the suture forms a broad saddle.
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.
The Uddenitinae, proposed by Miller and Furnish, and known from the Pennsylvanian
Pennsylvanian
The Pennsylvanian is, in the ICS geologic timescale, the younger of two subperiods of the Carboniferous Period. It lasted from roughly . As with most other geochronologic units, the rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain...
(U Carb
Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
) and Lower Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
, are transistional between the ancestral Pronoritidae and the more more traditional medlicottiids
Medlicottiidae
Medlicottiidae is a family of ammonoid cephalopods belonging to the Prolecanitida, known from the Upper Carboniferous to the Early Triassic.-Characteristics:...
Morphology
Genera of the Uddenitinae have narrow discoidal shells with narrow flat or sometimes grooved venters. Sutures are goniatitic to ceratitic with rounded saddles and slightly pointed to digitate lobes which form a declining series going toward the umbilicus. The ventral lobe is commonly long and narrow, and trifucated with sharp, simple prongs.Genera
The Uddenitinae includes Prouddenites, (ancestral form), Uddenites,(type genus), Daixites, Neouddenites, , and Uddenoceras.Prouddenites, named by Miller, 1930, which is found in the Pennsylvanian of the south-central United States and the Urals, has a discoidal shell with a flattened venter and a suture with an unequally trifid first lateral lobe. It is Intermedate between Pronorites and Uddenites.
Uddenites, named by Böse, 1919, known from the Upper Pennsylvanian of Texas and the Urals, has a discoidal shell with a retuse (grooved) venter. The ventral portion of the first lateral lobe is intermediate in depth.
Diaxites, Ruzhentsev 1941, has the characteristic discoidal form but the ventral lobe is quite wide, still trifid.
Diaxites is Upper Pennsylvanian and Lower Permian in age.
Neouddenites, Ruzhentsev 1961, is similar to Uddenites, but later, coming from the Lower Permian.
Uddenoceras, named by Miller and Furnish, 1954, from the Upper Pennsylvanian of Texas and the Urals has a discoidal shell like Uddenites, but the ventro-lateral portion of the suture forms a broad saddle.