Westonoceratidae

Tuyloceras percurvatum, from Teichert (1964).

Belongs within: Discosorida.

The Middle Ordovician to Middle Devonian westonoceratid lineage included the paraphyletic Westonoceratidae and its descendant families Lowoceratidae and Discosoridae.

Characters (from Teichert 1964): Conchs mostly compressed exogastric cyrtocones (endogastric in Discosoridae, slender in Lowoceratidae); siphuncles moderate-sized; apertures constricted or open. Connecting rings thin to moderately thick; bullettes inflated in early forms, less so in adult Lowoceratidae and Discosoridae; parietal deposits in interior of siphuncle, forming endocones in later forms. Cameral deposits may be present.

<==Westonoceratidae
    |  i. s.: Broeggeroceras Sweet 1958 T64
    |           `--*B. contractum Sweet 1958 T64
    |--Antiphragmoceras Foerste 1925 T64
    |    `--*A. ulrichi Foerste 1925 T64
    `--+--Simardoceras Flower 1957 T64
       |    `--*S. simardense Flower 1957 T64
       |--Sinclairoceras Flower 1952 T64
       |    `--*S. haha Flower 1952 T64
       `--+--Teichertoceras Foerste 1933 T64
          |    `--*T. husseyi Foerste 1933 T64
          `--+--+--Lavaloceras Flower 1952 T64
             |  |    `--*L. geniculatum Flower 1952 T64
             |  `--Winnipegoceras Foerste 1928 T64
             |       |--*W. laticurvatum (Whiteaves 1895) [=Cyrtoceras laticurvatum] T64
             |       |--W. humei Miller, Youngquist & Collinson 1954 P68
             |       |--W. royi Miller, Youngquist & Collinson 1954 P68
             |       `--W. sinclairi T64
             |--Westonoceras Foerste 1924 [=Westenoceras Foerste 1924; incl. Thuleoceras Troedsson 1926] T64
             |    |--*W. manitobense (Whiteaves 1890) [=Cyrtoceras manitobense] T64
             |    |--W. breviposticum P68
             |    |--W. cornulum P68
             |    |--W. deckeri Foerste 1935 P68
             |    |--W. iowense Foerste & Teichert 1930 P68
             |    |--W. ortoni P68
             |    |--W. rallsense Foerste & Teichert 1930 P68
             |    |--W. thompsoni Miller, Youngquist & Collinson 1954 P68
             |    |--W. washburni Miller, Youngquist & Collinson 1954 P68
             |    `--W. wilsonae Miller, Youngquist & Collinson 1954 P68
             `--+--Reedsoceras Foerste 1929 [=Conradoceras Foerste 1928 non Foerste 1926] T64
                |    `--*R. macrostomum (Hall 1847) [=Cyrtoceras macrostomum] T64
                |--Hecatoceras Teichert & Glenister 1952 T64
                |    `--*H. longinquum Teichert & Glenister 1952 T64
                |--Faberoceras Flower 1946 T64
                |    |--*F. multicinctum Flower 1946 T64
                |    `--F. saffordi Foerste in Flower 1946 P68
                |--Greenlandoceras Shimizu & Obata 1935 (see below for synonymy) T64
                |    |--*G. lineatum (Troedsson 1926) [=Sactoceras lineatum, *Sactocerina lineata] T64
                |    `--G. striatum T64
                |--+--Clarkesvillia Flower 1946 T64
                |  |    `--*C. halei Flower 1946 T64
                |  `--Glyptodendron Claypole 1878 T64
                |       |--*G. eatonense Claypole 1878 [=Cyrtoceras (Glyptodendron) eatonense] T64
                |       `--G. subcompressum T64
                `--+--Lowoceratidae T64
                   |    |--Lowoceras Foerste & Savage 1927 T64
                   |    |    `--*L. southamptonense Foerste & Savage 1927 T64
                   |    `--Tuyloceras Foerste & Savage 1927 T64
                   |         `--*T. percurvatum Foerste & Savage 1927 T64
                   `--Discosoridae T64
                        |--Endodiscosorus Teichert 1931 T64
                        |    `--*E. foerstei Teichert 1931 T64
                        |--Kayoceras Foerste 1934 T64
                        |    `--*K. biconoideum (Thomas 1915) [=Discosorus biconoideus] T64
                        |--Alpenoceras Foerste 1927 (see below for synonymy) T64
                        |    |--*A. ulrichi Foerste 1927 T64
                        |    `--A. eifelense T64
                        `--+--Stokesoceras Foerste 1924 T64
                           |    |--*S. romingeri Foerste 1924 T64
                           |    `--S. engadinense T64
                           `--Discosorus Hall 1852 T64
                                |--*D. conoideus Hall 1852 T64
                                |--D. austini Foerste 1934 P68
                                |--D. ehlersi T64
                                |--D. lyonsense Foerste 1934 P68
                                `--D. perexpansum Foerste 1934 P68

Alpenoceras Foerste 1927 [incl. Endostokesoceras Schindewolf 1944, Neodiscosorus Schindewolf 1944] T64

Greenlandoceras Shimizu & Obata 1935 [=Sactocerina Kobayashi 1936, incl. Striatoceras Shimizu & Obata 1935; Greenlandoceratidae, Striatoceratidae] T64

*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.

[T64] Teichert, C. 1964. Nautiloidea – Discosorida. In Treatise on Invertebrate Paleontology pt. K. Mollusca 3. Cephalopoda – General Features – Endoceratoidea – Actinoceratoidea – Nautiloidea – Bactritoidea (R. C. Moore, ed.) pp. K320-K342. The Geological Society of America and the University of Kansas Press.