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 Pennsylvanian may refer to: * A person or thing from Pennsylvania * Pennsylvanian (geology) The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, on the International Commission on Stratigraphy, ICS geologic timesc ...

Carb The California Air Resources Board (CARB or ARB) is an agency of the government of California that aims to reduce air pollution. Established in 1967 when then-governor Ronald Reagan signed the Mulford-Carrell Act, combining the Bureau of Air S ...

) and Lower

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

, are transitional between the ancestral Pronoritidae and the more traditional medlicottiids.

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 trifurcated 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 intermediate 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.

Generic phylogeny

''Prouddenties'' has its origin in the (Pronoritidae), probably in ''Uralopronorites'' from the Upper

Mississippian Mississippian may refer to: * Mississippian (geology), a subperiod of the Carboniferous period in the geologic timescale, roughly 360 to 325 million years ago * Mississippian cultures, a network of precontact cultures across the midwest and Easte ...

, and giving rise to ''Uddenites'' and ''Daixites''. ''Uddenites'' in turn gave rise to ''Uddenoceras'' and ''Neouddenties''. ''Daixites'' left no known descendants.

References

* Miller, Furnish, and Schindewolf, 1957. Paleozoic Ammonoidea (Prolecantina);

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...

, Part L, (Ammonoidea). Geol Soc of America and Univ Kansas Press. p. L72-L73.
Uddenitinae-Paleobio db
* Sunders, et al., 1999. Evolution of Complexity in Paleozoic Ammonoid Sutures. Supplementary material. List of ammonites Prolecanitida Permian ammonites Ammonites of North America Prehistoric animal subfamilies Pennsylvanian first appearances Cisuralian extinctions {{Prolecanitida-stub