Nothoceratidae

From Palaeos.org

Nothoceratidae conprise Silurian - Upper Devonian oncocerids of various form, mostly all with contracted or visored apertures and venrtral siphuncles with concave segments that contain actinosiphonate depostis.. Shells include endogastric and exogasric brevicones, planispiral nautilicones, and trochoidal torticones. Derivation is from the Oncoceratidae, probably from Oonoceras through Perimecoceras. No descendant group is known.

A tentative phylogeny, showing included genera, follows.

<==Nothoceratidae [Bolloceratidae, Cranoceratidae,
 Cyrtoceratidae] 
  |-Perimecoceras Foerste, 1926, U Sil
  |-Lorieroceras Foerste, 1926, L Dev
  |-Nothoceras Barrande, 1856, M Dev 
  |-Blakeoceras Foerste, 1926, Sil- M Dev
  | `-Conostichoceras Foeste, 1926, M Dev
  |-Paraconradoceras Foerste, 1926 M Dev
  | |-Megaphragmoceras Flower, 1938  M Dev
  | `-Bolloceras Foerste 1926, M-U Dev. 
  |-Turnoceras Foerste, 1926, M Dev
    `-Cyrthocerites d'Archiac & DeVerneuil 1842.  

References

Sweet, W. C. 1964. Nautiloidea – Oncocerida. In Treatise on Invertebrate Paleontology pt. K. Mollusca 3. Cephalopoda – General Features – Endoceratoidea – Actinoceratoidea – Nautiloidea – Bactritoidea (R. C. Moore, ed.) pp. K277-K319. The Geological Society of America and the University of Kansas Press.

Credits

Christopher 00:44, 6 April 2010 (UTC)
John M 27 May 2012