Blepharipodidae is a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

of sand crabs (

Hippoidea Hippoidea is a superfamily of decapod crustaceans known as sand crabs or mole crabs. Ecology Hippoids are adapted to burrowing into sandy beaches, a habit they share with raninid crabs, and the parallel evolution of the two groups is strikin ...

), comprising the two genera '' Blepharipoda'' and '' Lophomastix''. They are distinguished from the other families in the superfamily Hippoidea by the form of the

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

s, which are trichobranchiate (filamentous) in Blepharipodidae, but phyllobranchiate (lamellar) in

Albuneidae Albuneidae is a little-known family of specialized burrowing sand crabs. There are 50 extant species as well as nine fossil species that have been described. Fossil specimens have been described from the Cretaceous, Miocene The Miocene ( ) i ...

and

Hippidae Hippidae is a family of decapod crustaceans, currently known by the English name as either mole crab or sand crab, and by an earlier English name as sand bug. They are closely related to the family Albuneidae, with which they are usually joined ...

. Fossils belonging to the genus ''Lophomastix'' have been found in rocks dating back to the

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

References

{{Taxonbar, from=Q4926098 Hippoidea Decapod families