Tornoceratidae is a family of goniatitid

ammonoids Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

from the middle and upper

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

. The family is included in the suborder

Tornoceratina Tornoceratina is one of two suborders included in the Goniatitida, characterized by generally involute, subdiscoidal shells and by sutures in which the ventral ones are undivided. Sutural lobes increase in number during the course of life of th ...

and the superfamily

Tornoceratoidea Tornoceratoidea, also known as Tornocerataceae, is a superfamily of goniatitid ammonoids included in the suborder Tornoceratina. Tornoceratoidea, or Tornocerataceae, is essentially the Cheilocerataceae of Miller, Furnish, and Schindewolf (195 ...

. Tornoceratids are subdiscoidal goniatitids with biconvex growth lines and sutures that form 6 to 10 lobes, the ventral one undivided, the lateral ones originating as subdivisions of external and internal lateral saddle. They are derived from the

Anarcestida Agoniatitida, also known as the Anarcestida, is the ancestral order within the cephalopod subclass Ammonoidea originating from bactritoid nautiloids, that lived in what would become Africa, Asia, Australia, Europe, and North America during the ...

Taxonomy

Tornoceratidae as now understood is essentially the Tornoceratidae of Arthaber (1911) described in the American

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 ...

, Part L, revised to include three subfamilies, the Tornoceratinae, Aulatornoceratinae, and Falcitornoceratinae. Miller ''et al''. (1957) included the Tornoceratidae without subfamilies in the Cheilocerataceae, a superfaminily in the Goniatitida which also includes the Cheiloceratidae. Tornoceratinae is based on the genus ''Tornoceras'' described by

Alpheus Hyatt Alpheus Hyatt (April 5, 1838 – January 15, 1902) was an American zoologist and palaeontologist. Hyatt served as the founding president of the American Society of Naturalists from 1883 to 1884 and was the founding editor of the journal '' T ...

in 1884. Aulatornoceratinae and Falcitornoceratinae were established by Becker in 1993; Aulatornoceratinae based on ''

Aulatornoceras ''Aulatornoceras'' is a genus belonging to the subfamily Aulatornoceratinae, a member of the Goniatitida, an extinct order of shelled cephalopods included in the Ammonoidea Ammonoids are extinct, (typically) coiled-shelled cephalopods compri ...

'', named by Schindewolf in 1922; Falcitornoceratinae on '' Falcitornoceras'', named by House and Price in 1985. The Tornoceratinae form the root stock of the tornoceratids and are derived from

. Tornoceratinae in turn gave rise to Aulatornoceratinae and Falcitornoceratinae. The Tornoceratinae includes ''Tornoceras'', ''Epitornoceras'', ''Lobotornoceras'', ''Protornoceras'', and ''Tornia'', described in the Treatise (L 1957), along with ''Crassotornoceras'', ''Linguatornoceras'', ''Domanikoceras'', ''Simcheiloceras'', and ''Oxytornoceras'' which were added later. ''Aulatornoceras'', type for the Aulatornoceratinae was previously considered a subgenus of ''Tornoceras'' and is known from the Upper Devonian of North America and Europe. ''Aulatornoceras'' gave rise to ''Truyolsoceras'' and ''Polonoceras'', which gave rise to ''Armatites'', ''Kirsoceras'', and ''Pernoceras'', which gave rise to ''Pseudoclymenia'' making up the Aulotornoceratidae. Genera making up the Falcitornoceratinae form an evolutionary series, ''Phoenixites'', ''Falcitornoceras'', ''Gundolficeras'', ''Exotornoceras'', leading up to ''Posttornoceras'', type genus of the

Posttornoceratidae The Posttornoceratidae are Late Devonian Goniatitida, goniatites (Ammonoidea) included in the superfamily Tornoceratoidea. The family, Posttornoceratidae, named by Bogoslovsky in 1962, is based on the genus ''Posttornoceras'', named by Wedekind i ...

Descendants

The Tornoceratidae probably gave rise to the Cheiloceratidae (Miller et al. 1964, fig 12, L27) but though which genus is unspecified (Saunders et al. 2004). The Tornoceratidae may also have given rise, though ''Tornoceras'' to the

Clymeniida Clymeniida is an order of ammonoid cephalopods from the Upper Devonian characterized by having an unusual dorsal siphuncle. They measured about in diameter and are most common in Europe, North Africa, and South China but are known from North ...

References

*Miller, Furnish, and Shindewolf (1957) Paleozoic Ammonoidea; in the Treatise on Invertebrate Paleontology, Part L, Mollusca 4 Ammonoidea; GSA and University of Kansas press. *Saunders, Work, and Nikoleava 1999, Evolution of Complexity in Paleozoic Ammonoid Sutures, Supplementary Material. Science magazine on-lin

*Tornoceratidae i
Goniat OnlineTornoceratidae
Paleobiology Database. {{Taxonbar, from=Q7826140 Tornoceratidae, Goniatitida families Tornoceratoidea Middle Devonian first appearances Late Devonian animals Late Devonian extinctions