Mollusca		Nautiloidea
CYRTOSOMA		Barrandeocerina

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Barrandeocerina

Cephalopoda
|--NAUTILOIDEA
|  |--TARPHYCERIDA
|  |  |--Tarphycerina  
|  |  `--BARRANDEOCERINA
|  `--ONCOCERIDA 
|     |--Oncoceratidae  
|     `--NAUTILIDA    
|        |--NAUTILIDA i.s.
|        `--NAUTILINA
`--Neocephalopoda
   |--Ammonoidea
   `--Coleoidea

Introduction

These nautiloids are very similar in form and structure to the tarphycerids, among which they are now generally included as a suborder. They may have developed from the family Tarphyceratidae. A number of Ordovician genera may be placed equally in the Tarphyceratida and Barrandeoceratida.  

Technical Diagnosis

Nautilicones with the siphuncle primitively tubular, connecting rings thin, homogeneous, siphuncle central or ventral.

Families and Genera

The following list is in no way definitive, up to date, or comprehensive. It is mostly from on Flower and Kummel, p.613. The dates are from The Fossil Record II

Family BARRANDEOCERATIDAE Foerste
Coiled nautiloids, dominantly compressed, siphuncle subcentral, secondarily ventral.
Middle Ordovician to Early Devonian (Darriwilian to Eifelian)
Ordovician: Barrandeoceras, Deitoceras(?), Centrocyrtoceras, Paquettoceras.
Ord.-Sil.: Bickmorites, (= Tyrreiloceras, Leuronotoceras, Goniotrochoceras).
Sil.: Gasconsoceras, Laureloceras.
Dev.: Haydenoceras.

Family PLECTOCERATIDAE Hyatt.
Costate shells, the siphuncle close to the venter in the adult. Possibly descended from the Barrandeoceratidae
Middle Ordovician to Middle Silurian (Darriwilian to Wenlock)
Plectoceras (= Metaplectoceras).

Family URANOCERATIDAE Hyatt.

Gerontically uncoiled forms derived from Bickmorites, the siphuncle tending to expand in the camerae, the surface becoming simple.
?Late Ordovician to Silurian. (?Hirnantian to ?Ludlow)
Jolietoceras, Uranoceras, Cumingsoceras (= Gigantoceras elrodi (White)).

Family LECHRITROCHOCERATIDAE Flower

Dextral costate trochoceroids, probably derived from Bickmorites (Barrandeoceratidae). Dzik 1984 considers the Lechritrochoceratids as ancestral to the Nautilids. Teichert 1988 considers this unlikely Lechritrochoceratids have costate, torticonic shells which would make them unlikely candidates for the planispiral early Nautilida.
Mid to Late Silurian (Wenlock to Pridoli)
Lechritrochoceras, Leurotrochoceras, Peismoceras, Systrophoceras, Catyrephoceras, Trochodictyoceras.

Family NEPHRITICERATIDAE

Trochoceroids, gyrocones, nautilicones and brevicones. Siphuncle becomes central and broadly expanded. Probably derived from Bickmorites (Barrandeoceratidae). Also known as Rhadinoceratidae Hyatt
Devonian (Emsian to Frasnian).
Sphyradoceras. Baeopleuroceras, Lyrioceras, Nephriticerina, Endoplanoceras, Heracloceras, Nephriticeras, Rhadinoceras, Hipparionoceras?

Family APSINOCERATIDAE Hyatt

Coiled shells, developing a broad flat venter, lateral lobes, a subcentral cyrtochoanitic siphuncle. This late Ordovician group is probably derived from the Barrandeoceratidae
Late Ordovician (Sandbian to Hirnantian).
Apsidoceras, Deckeroceras, Fremontoceras, Charactoceras, Charactocerina, Wilsonoceras.

Family LITUITIDAE Noetling.

Lituites lituus Montford
Middle Ordovician (Darriwilian), Baltic region
Length : 30 cm
image from Moore, Lalicker and Fischer, Invertebrate Fossils, p.357

Coiled shells, secondarily becoming straight, siphuncle subcentral, tubular, growth lines with ventral and a pair of lateral sinuses.
Early to Late Ordovician (?Floian to Hirnantian).
Lituites, Cyclolituites, Angelinoceras, Tyrioceras, Holmiceras, Aneistroceras, Rhynchorthoceras.

Family OPHIDIOCERATIDAE Hyatt
Small forms, shell almost entirely coiled, deep funnel sinus, probably very agile swimmers. Presumably descended from Lituitidae
Silurian (Wenlock to Ludlow)
Ophidioceras