Pseudohaloritidae is the larger of two families that form the goniatitid superfamily

Pseudohaloritoidea Pseudohaloritoidea, formerly Pseudohaloritaceae, is one of four superfamilies of the goniatitid suborder Tornoceratatina. Although attributed the Ruzhencev, 1957 (Ruzhencev named the Pseudohaloritidae, March 1957, eight months ahead of Miller a ...

, the other being the monogenerc Maximitidae. They are part of the vast array of shelled cephalopods known as

ammonoids Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttle ...

that are more closely related to

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...

belemnite Belemnitida (or the belemnite) is an extinct order of squid-like cephalopods that existed from the Late Triassic to Late Cretaceous. Unlike squid, belemnites had an internal skeleton that made up the cone. The parts are, from the arms-most to ...

octopus An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttle ...

es, and

cuttlefish Cuttlefish or cuttles are marine molluscs of the order Sepiida. They belong to the class Cephalopoda which also includes squid, octopuses, and nautiluses. Cuttlefish have a unique internal shell, the cuttlebone, which is used for control of ...

, than to the superficially similar ''

Nautilus The nautilus (, ) is a pelagic marine mollusc of the cephalopod family Nautilidae. The nautilus is the sole extant family of the superfamily Nautilaceae and of its smaller but near equal suborder, Nautilina. It comprises six living species in t ...

''.The Paleobiology Database
11/17/09 The Pseudohaloritide which now contains some 14 genera in three subfamilies is characterized by small, subdiscoidal to subglobular, involute shells, the surface of which may be smooth or with coarse longitudinal lirae and/or transverse ribs. The

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

is retrosiphonitic, a hold-over character from the

nautiloids 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 species. ...

, usually subcentral or situated within dorsal septal flexure but ventral-marginal in first and second whorls. Sutures have four pairs of lobes, the ventral one being rounded and spatulate, the interior three clustered and narrow. External lobes are either smooth are variably serrate.Miller, A.K. and W.M Furnish, 1957, Permian Ammonoids from Southern Arabia; Jour Paleontology V.31, N. 6, pp 1043-1051; Nov. 1957 The Pseudohaloritidae was established by Miller and Furnish (1957) for three related genera with similar sutures and aberrant siphuncles that are removed from the ventral margin. One, Maximites, has been put in a family of its own, the Maximitidae. The other two, Neoaganides and Pseudohalorites are retained in the Pseudohaloritidae, to which has been added about a dozen more genera, mostly from China. ''Maximites'' differs in having a bifid ventral lobe and a siphuncle that is ventral, but not marginal. It is also older, as early as the Middle Pennsylvanian (m U Carb) rather than from the Upper Pennsylvanian (uU Carb) when pseudohaloritids, as emended, make their first appearance.
Saunders et al. 1999 Maximites is thought to have given rise to the Neoaganides and thus to the Pseudohaloritidae, and in turn may have been derived from ''Imitoceras''. On the other hand, the suture indicates that ''Neoaganides'' may have developed directly from ''Imitoceras''. The ventral lobe of ''Neoaganides'' is like that of ''Imitoceras'', smooth and rounded, but the lateral lobes differ from those of both ''Imitoceras'' and ''Maximites'' in being pointed. The aberrant position of the siphuncle well away from the ventral margin and in some near the dorsum is characteristic of, although not unique to, this family. However no link is indicated between these Pennsylvanian and

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...

forms and the Upper

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...

Clymeniids with their well established dorso-marginal siphuncles.

References

Pseudohaloritoidea Goniatitida families {{Goniatitida-stub