Proteoceratidae

Isorthoceras, from 3d Fossils.

Belongs within: Michelinoceratida.

The Proteoceratidae were a Middle Ordovician to Middle Silurian family of orthocerid cephalopods.

Characters (from Sweet 1964): Smooth or annulated orthocones and exogastric cyrtoconeswith expanded cyrtochoanitic siphuncular segments in early stages and narrower, subcylindrical, orthochoanitic segments in later stages. Siphuncular deposits consist of annuli developing into parietal deposits by growth forward, backward, or in both directions from septal foramen. Cameral deposits usually well developed.

<==Proteoceratidae [Hammelloceratidae]
    |--Proteoceras Flower 1955 S64
    |    `--*P. perkinsi (Ruedemann 1906) [=Oonoceras perkinsi] S64
    |--Cyrtactinoceras Hyatt in Zittel 1900 [=Cyrtoactinoceras (l. c.)] S64
    |    `--*C. rebelle (Barrande 1866) [=Cyrtoceras rebelle] S64
    |--Isorthoceras Flower 1962 S64
    |    `--*I. sociale (Hall in Miller 1877) [=Orthoceras sociale] S64
    |--Metephippiorthoceras Zhuravleva 1957 S64
    |    `--*M. helenae Zhuravleva 1957 S64
    |--Monomuchites Wilson 1961 S64
    |    `--*M. costalis Wilson 1961 S64
    |--Stereospyroceras Flower 1955 S64
    |    `--*S. champlainense Flower 1955 S64
    |--Tofangoceras Kobayashi 1927 (see below for synonymy) S64
    |    `--*T. pauciannulatum Kobayashi 1927 S64
    |--Gorbyoceras Shimizu & Obata 1935 (see below for synonymy) S64
    |    |--*G. gorbyi (Miller 1894) [=Orthoceras gorbyi] S64
    |    `--G. duncanae S64
    `--Ephippiorthoceras Foerste 1924 S64
         |--*E. formosum (Billings 1857) [=Orthoceras formosum] S64
         |--E. baffinense Foerste 1928 P68
         |--E. compressum Foerste 1928 P68
         `--E. dowlingi P68

Gorbyoceras Shimizu & Obata 1935 [incl. Hammelloceras Shimizu & Obata 1935, Porteroceras Shimizu & Obata 1935] S64

Tofangoceras Kobayashi 1927 [incl. Kogenoceras Shimizu & Obata 1936, Pseudeskimoceras Shimizu & Obata 1936, Tofangocerina Kobayashi 1936, Toufangocerina (l. c.)] S64

*Type species of generic name indicated

REFERENCES

[P68] Purnell, L. R. 1968. Catalog of the Type Specimens of Invertebrate Fossils. Part I: Paleozoic Cephalopoda. United States National Museum Bulletin 262: 1-198.

[S64] Sweet, W. C. 1964. Nautiloidea – Orthocerida. In Treatise on Invertebrate Paleontology pt. K. Mollusca 3. Cephalopoda – General Features – Endoceratoidea – Actinoceratoidea – Nautiloidea – Bactritoidea (R. C. Moore, ed.) pp. K216-K261. The Geological Society of America and the University of Kansas Press.