Belongs within: Acanthoceratoidea.
The Forbesiceratidae are a Cretaceous (Upper Albian to Cenomanian) lineage of very involute, compressed ammonites (Wright et al. 1996).
Characters (from Wright et al. 1996): Very involute, compressed, and high-whorled, with flat or slightly convex sides; venter narrow and fastigiate or flat or sulcate, with 0, 1, 2, or 3 keels; smooth or with fine ribs; midlateral tubercles rarely present; ventrolateral tubercles commonly present. Suture with long, narrow elements; saddles tending to be phylloid, lobes to be bifid; with adventive lobe in first lateral saddle.
<==Forbesiceratidae [Forbesiceratinae]WCH96 |--Paradolphia Casey 1965WCH96 | `--*P. prisca Casey 1965WCH96 `--Forbesiceras Kossmat 1897 (see below for synonymy)KK08 |--*F. largilliertianum (d’Orbigny 1841) (see below for synonymy)KK08 |--F. baylissi Wright & Kennedy 1984KK08 |--F. beaumontianum (d’Orbigny 1841) [=Ammonites beaumontianus]KK08 |--F. bicarinatum Szász 1976KK08 |--F. brundrettei (Young 1958)KK08 |--F. chevillei (Pictet & Renevier 1866) (see below for synonymy)KK08 |--F. conlini Stephenson 1953KK08 |--F. douvillei (Collignon 1929) [=Pulchellia (Neopulchellia) douvillei]KK08 |--F. flicki Pervinquière 1907KK08 |--F. furnishi Collignon 1964KK08 |--F. gignouxi (Collignon 1929) [=Pulchellia (*Neopulchellia) gignouxi]KK08 |--F. mikasaense Matsumoto 1986KK08 |--F. obtectum (Sharpe 1853)KK08 |--F. pseudobtectum Collignon 1964KK08 |--F. subobtectum (Stoliczka 1864) [=Ammonites subobtectus]KK08 |--F. tenuipunctatum Collignon 1964KK08 `--F. varicostatum Zaborski 1990KK08
Forbesiceras Kossmat 1897 [=Cenomanites Haug 1898, Discoceras Kossmat 1895 nec Barrande 1867 nec Hyatt 1867; incl. Neopulchellia Collignon 1929]KK08
Forbesiceras chevillei (Pictet & Renevier 1866) [=Ammonites chevillei; incl. F. almerae (Mallada 1891), F. clarki Collignon 1964, F. nodosum Crick 1907, F. sculptum Crick 1907]KK08
*Forbesiceras largilliertianum (d’Orbigny 1841) [=Ammonites largilliertianus, *Cenomanites largilliertianus, *Discoceras largilliertianum]KK08
*Type species of generic name indicated
References
[KK08] Kennedy, W. J., & H. C. Klinger. 2008. Cretaceous faunas from Zululand and Natal, South Africa. The ammonite family Forbesiceratidae Wright, 1952. African Natural History 4: 117–130.
[WCH96] Wright, C. W., J. H. Calloman & M. K. Howarth. 1996. Treatise on Invertebrate Paleontology pt L. Mollusca 4, revised vol. 4. Cretaceous Ammonoidea. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).