''Huronia'' is an

actinocerid The Actinocerida are an order of generally straight, medium to large cephalopods that lived during the early and middle Paleozoic, distinguished by a siphuncle composed of expanded segments that extend into the adjacent chambers, in which deposit ...

genus included in the Huroniidae along with ''Discoactinoceras'' and ''Huroniella'',(Teichert 1964). ''Huronia'' is characterized by long siphuncle segments with the free part of the connecting rings only slightly inflated and by a narrow central canal and strongly curved radial canals located in the anterior part of each

siphuncle The siphuncle is a strand of biological tissue, tissue passing longitudinally through the mollusc shell, shell of a cephalopod mollusc. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the li ...

segment

Ancestry

Teichert, (1964) indicated ''Huronia'' as being derived from the upper Middle

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...

''Discoactinoceras'', whose ancestry lay in the direction of ''Polydesmia'', once considered the prototypical actinocerid. Flower, (1968) on the other hand, showed that ''Huronia'' is derived from ''

Actinoceras ''Actinoceras'' is the principal and root genus of the Actinoceratidae, a major family in the Actinocerida, that lived during the Middle and Late Ordovician. It is an extinct genus of nautiloid cephalopod that thrived in the warm waters of the Un ...

'' and split off from ''

Lambeoceras ''Lambeoceras'' is a genus of large actinocerids with a convexly lenticular cross section from the Upper Ordovician of North America and the sole representative of the family Lambeoceratidae. Morphological description ''Lambeoceras'' is of med ...

'' during Red River time, near the start of the Late Ordovician, precluding the inclusion of ''Discoactinoceras''

Distribution

''Huronia'' is known from the Upper Ordovician and

Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

of North America and Greenland. ''H. arctica'' and ''H occidentalis''(?) are associated with the Cape Calhoun fauna in Greenland.(Flower 1957) ''H paulodolata'' and ''H munuens'' come from the Middle Silurian of Michigan (Teichert 1964) ''H sepata'' is found in the Shamattawa limestone of Hudson Bay (Flower 1957)

References

* Flower R.H. 1957, Studies of the Actinocerida. Memoir 2, New Mexico Bureau of Mines and Mineral Resources, Socorro NM. * Flower R.H. 1968, The First Great Expansion of the Actinocerids. Part I Memoir 19, New Mexico Bureau of Mines and Mineral Resources, Socorro NM. * Teichert, C. 1964, Actinoceroidea (K190) in the

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...

, vol K, Nautiloidea. Curt Teichert and R.C. Moore Eds. University of Kansas Press and the GSA. {{Taxonbar, from=Q5946981 Actinocerida Late Ordovician first appearances Silurian extinctions Paleozoic life of Manitoba Paleozoic life of Nunavut