''Mcqueenoceras'' is an extinct genus of early

endocerid Endocerida is an extinct nautiloid order, a group of cephalopods from the Lower Paleozoic with cone-like deposits in their siphuncle. Endocerida was a diverse group of cephalopods that lived from the Early Ordovician possibly to the Late Silurian ...

, a

nautiloid Nautiloids are a group of marine cephalopods (Mollusca) which originated in the Late Cambrian and are represented today by the living ''Nautilus'' and '' Allonautilus''. Fossil nautiloids are diverse and speciose, with over 2,500 recorded specie ...

from the

Floian The Floian is the second stage of the Ordovician Period. It succeeds the Tremadocian with which it forms the Lower Ordovician epoch. It precedes the Dapingian Stage of the Middle Ordovician. The Floian extended from to million years ago. The ...

epoch of the late early

Ordovician period The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. Th ...

. It was similar in overall form to '' Clitendoceras'', from which it may have been derived. ''Mcqueenoceras'', like ''Clitendoceras'', has ventral siphuncle but the endocones are thicker on the ventral side and thinner on the dorsal. Also the sutures in ''Mcqueenoceras'' retreat rearward, forming lobes as they cross the venter. The type species is ''Mcqueenoceras jeffersonense'', named by E.O. Ulrich and A.F. Foerste in 1935, and it is known from

Missouri Missouri is a state in the Midwestern region of the United States. Ranking 21st in land area, it is bordered by eight states (tied for the most with Tennessee): Iowa to the north, Illinois, Kentucky and Tennessee to the east, Arkansas t ...

and New York. In 1956, Rousseau H. Flower named two other species, ''M. cariniferum'' and ''M. ventrale'', both known from

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...

References

*Flower, R. H. 1964; Memoir 12, The Nautiloid Order Ellesmeroceratida (Cephalopoda), pp 126, 147, 148. NMBM&MR, Socorro N.M. *Teichert, C, 1964, ''Mcqueenoceras'', p 166 in Proterocameroceratidae, pp 166–170 in the

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and co ...

, Vol K. GSA and Univ Kansas Press. {{Taxonbar, from=Q6802821 Nautiloids Prehistoric nautiloid genera Ordovician cephalopods of North America