Khairkhaniidae is an extinct
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
of
Paleozoic
The Paleozoic ( , , ; or Palaeozoic) Era is the first of three Era (geology), geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic (the last era of the Proterozoic Eon) and ends 251.9 Ma a ...
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...
mollusc
Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...
s of uncertain position. They are thought to belong to either the
Gastropoda
Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, freshwater, and fro ...
or
Monoplacophora
Shell of Monoplacophora
Monoplacophora , meaning "bearing one plate", is a polyphyletic class of molluscs with a cap-like shell, inhabiting deep sea environments. Extant representatives were not recognized as such until 1952; previously they wer ...
.
They possess planispiral coiled shells with a columnar microstructure.
2005 taxonomy
The
taxonomy of the Gastropoda by Bouchet & Rocroi, 2005[Bouchet P. & Rocroi J.-P. (Ed.); Frýda J., Hausdorf B., Ponder W., Valdes A. & Warén A. 2005. ''Classification and nomenclator of gastropod families''. Malacologia: International Journal of Malacology, 47(1-2). ConchBooks: Hackenheim, Germany. . ISSN 0076-2997. 397 pp. http://www.vliz.be/Vmdcdata/imis2/ref.php?refid=78278] categorizes Khairkhaniidae within the
Paleozoic molluscs of uncertain systematic position. This family is unassigned to superfamily. This family has no subfamilies.
2006–2007 taxonomy
According to the P. Yu. Parkhaev, the Khairkhaniidae is the only family in the order Khairkhaniifomes within the subclass Divasibranchia.
* Class
Helcionelloida
Helcionelloida is an extinct group of ancient molluscs (phylum Mollusca). 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 ere ...
** Subclass Divasibranchia Minichev & Starobogatov, 1975
*** Order Khairkhaniifomes Parkhaev, 2001
**** Family Khairkhaniidae Missarzhevsky, 1989
Genera
Genera in the family Khairkhaniidae include:
* ''
Khairkhania'' Missarzhevsky, 1981 -
type genus
In biological taxonomy, the type genus (''genus typica'') is the genus which defines a biological family and the root of the family name.
Zoological nomenclature
According to the International Code of Zoological Nomenclature, "The name-bearin ...
of the family Khairkhaniidae
** ''
Khairkhania rotata'' Missarzhevsky, 1981
*
Barskovia
References
Helcionelloida
{{paleo-mollusc-stub