Parafossarulus crassitesta
Encyclopedia
Parafossarulus crassitesta is an extinct species
of freshwater snail
with gill
s and an operculum
, an aquatic
prosobranch gastropod mollusk in the family
Bithyniidae
.
Glöer (2002) reassigned two European extinct species of Parafossarulus as a subgenus of the genus Bithynia
, but genus Parafossarulus is generally accepted for Asian species.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of freshwater snail
Freshwater snail
A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....
with gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
s and an operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...
, an aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
prosobranch gastropod mollusk in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Bithyniidae
Bithyniidae
Bithyniidae is a family of small freshwater snails with an operculum, aquatic gastropod molluscs in the clade Littorinimorpha.Their minute shell is often colored. They are characterized by a calcareous operculum, a lobe on the upper surface of the neck. The ctenidium, the respiratory gill-comb, is...
.
Glöer (2002) reassigned two European extinct species of Parafossarulus as a subgenus of the genus Bithynia
Bithynia (genus)
Bithynia is a genus of small freshwater snails with an operculum, aquatic prosobranch gastropod mollusks in the family Bithyniidae.The diploid chromosome number of Bithynia sp...
, but genus Parafossarulus is generally accepted for Asian species.