Baltoceratidae

Ventral, dorsal and septal views of Murrayoceras murrayi. Figures from Furnish & Glenister (1964).

Belongs within: Cephalopoda.

The Lower to Middle Ordovician Baltoceratidae were a family of relatively large orthoconic early cephalopods.

Characters (from Furnish & Glenister 1964): Smooth, longiconic orthocones with moderately large marginal siphuncle, orthochoanitic septal necks and thin homogenous connecting rings.

<==Baltoceratidae [Cochlioceratidae]
    |--Bactroceras Holm 1898 FG64
    |    `--*B. avus Holm 1898 FG64
    |--Murrayoceras Foerste 1926 FG64
    |    `--*M. murrayi (Billings 1857) [=Orthoceras murrayi] FG64
    |--Ogygoceras Ulrich, Foerste et al. 1944 FG64
    |    `--*O. gracile Ulrich, Foerste et al. 1944 FG64
    |--Cochlioceras Eichwald 1860 [incl. Baltoceras Holm 1897, Protobaltoceras Troedsson 1937] FG64
    |    |--*C. avus (Eichwald 1857) [=Orthoceras avus] FG64
    |    `--C. burchardii FG64 [=Baltoceras burchardi S64]
    `--Pachendoceras Ulrich & Foerste 1936 FG64
         |--*P. huzzahense (Ulrich & Foerste in Bridge 1931) [=Cameroceras huzzahense] FG64
         |--P. confertum Ulrich, Foerste et al. 1944 P68
         |--P. newportense Ulrich, Foerste et al. 1944 P68
         `--P. tardum Ulrich, Foerste et al. 1944 P68

*Type species of generic name indicated

REFERENCES

[FG64] Furnish, W. M., & B. F. Glenister. 1964. Nautiloidea - Ellesmerocerida. In Treatise on Invertebrate Paleontology pt. K. Mollusca 3. Cephalopoda – General Features – Endoceratoidea – Actinoceratoidea – Nautiloidea – Bactritoidea (R. C. Moore, ed.) pp. K129-K159. The Geological Society of America and the University of Kansas Press.

[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.