| Lesueurillidae | |
|---|---|
 | |
| Lesueurilla helix | |
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Superfamily: | |
| Family: | Lesueurillidae P. J. Wagner, 2002 [1] |
| Genera | |
see text. | |
Lesueurillidae is an extinct family of paleozoic molluscs (gastropods?) with anisostrophically coiled shells of uncertain position (Gastropoda?) (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).
The taxonomy of the Gastropoda by Bouchet & Rocroi, 2005 [2] categorizes Lesueurillidae in the superfamilia Euomphaloidea within the Paleozoic molluscs with anisostrophically coiled shells of uncertain position (Gastropoda?). This family has no subfamilies.
Genera in the family Lesueurillidae include [3]
Fossils of family Lesueurillidae has sharp peripheral band and a short notch formed from deep V-shaped sinus. [1] They are similar to Maclurites but they differ in early ontogenesis from them. [1]
Strepsodiscus is an extinct genus of very primitive fossil snail-like molluscs from the early part of the Late Cambrian of North America. The coiled, slightly asymmetrical shells are about 3 cm in height. It is not known whether these are shells of gastropods or monoplacophorans, which are more primitive mollusks.
The Bellerophontidae are an extinct family of specialized globose bellerophontids, Paleozoic and early Triassic mollusks of the class Gastropoda.
Latouchella is an extinct genus of marine invertebrate animal, that is considered to be a mollusk and which may be a sea snail, a gastropod. It is a helcionellid from the Tommotian epoch of what is now Siberia. Its tightly-coiled, spiral shell contains a number of low "walls" running up the front surface of the interior; these would have directed water currents within its shell. Between these walls are a series of furrows, parallel to the shell's aperture, giving casts of the internal structure the appearance of a railway line, with sleepers tying together paired rails that run towards the apex of the shell.
The Euomphalina comprise a major suborder of mainly Paleozoic archaeogastropods, shells of which are hyperstophic to depressed orthstrophic, commonly with an angulation at the outer upper whorl surface thought to be coincident with the exhalent channel; shell wall thick, outer layer calcitic, inner layers aragonitic but not nacreous; operculum calcareous and heavy. Their range is from the Upper Cambrian to the Triassic, and possibly as high as the Upper Cretaceous.
Helcionelloida is an extinct group of ancient molluscs. These are the oldest known conchiferan molluscs, that is, they had a mineralised shell. Some members of this class were mistaken for Monoplacophorans. The class was erected by Peel in 1991.
Coreospiridae is an extinct family of Paleozoic molluscs of uncertain position taxonomically. They might be snails (Gastropoda), Helcionelloida, or they might be Monoplacophora.
Euomphalidae is an extinct family of Paleozoic to early Mesozoic marine molluscs which may be gastropods with anisostrophically coiled shells . The shells show a selenizone.
Bucanellidae is an extinct family of Paleozoic molluscs of uncertain position, belonging either to Gastropoda (snails) or Monoplacophora. The family lived from the upper Cambrian to middle Permian and the shells are characterized by a relatively small median sinus in the upper margin of the aperture, and collabral (transverse) or spiral (longitudinal) threads covering the shell. The shells are planispirally coiled rather than trochospirally with a spire as is the case with most shelled gastropods.
Tropidodiscidae is an extinct family of Paleozoic fossil molluscs with isostrophically coiled shells. They are of uncertain position taxonomically, in other words it is not known whether they were s.
Tremanotidae is an extinct family of Paleozoic fossil molluscs with isostrophically coiled shells. They occupy an uncertain position taxonomically: it is not known whether they were (gastropods or monoplacophorans.
Bucaniidae is an extinct family of Paleozoic molluscs of uncertain position possibly being either gastropods or monoplacophorans in the superfamily Bellerophontoidea. The family lived from the Lower Ordovician to the Devonian and have shells in which the apertural margins tend to flare. Most genera have a slit and selenizone, others some modification of this feature.
Euphemitidae is an extinct family of Paleozoic fossil molluscs of uncertain position. They have isostrophically coiled shells and may be either Gastropoda sea (snail)s, or Monoplacophora.
Pterothecidae is an extinct family of Paleozoic molluscs of uncertain position, either Gastropoda or Monoplacophora, with isostrophically coiled shells.
Sinuitidae is an extinct family of Paleozoic molluscs of uncertain position. They had isostrophically coiled shells.
Macluritidae is an extinct family of relatively large, Lower Ordovician to Devonian, macluritacean gastropods(?), hypserstrophically coiled, that is dextral while appearing sinsitral, of which the genus Maclurites is arch-typical. The base of their shells is flat or gently protruding while the upper side is generally concave.
Omphalotrochidae is an extinct taxonomic family of Paleozoic molluscs (gastropods?) with anisostrophically coiled shells of uncertain position (Gastropoda?).
Omphalocirridae is an extinct family of Paleozoic molluscs (gastropods?) with anisostrophically coiled shells of uncertain position (Gastropoda?).
Helicotomidae is an extinct family of Paleozoic molluscs (gastropods?) with anisostrophically coiled shells of uncertain position (Gastropoda?).
Isospiridae is an extinct family of fossil sea snails, Paleozoic gastropod mollusks.
Euomphaloidea, originally Euomphalacea, is an extinct superfamily of marine molluscs that lived from the Early Ordovician to the Late Cretaceous, included in the Gastropoda but speculated as instead perhaps Monoplacophora.