Family of gastropods
Patellidae is a taxonomic family of true limpets, marine gastropod molluscs in the superfamily Patelloidea. 
The largest known limpet in the world is "Scutellastra mexicana" that can reach in length.
Taxonomy.
A cladogram showing phylogenic relations of Patellogastropoda based on molecular phylogeny research by Nakano &amp; Ozawa (2007):
Genera.
There are four extant genera in the family Patellidae:
There are two exclusively fossil genera:
Synonyms.
Synonyms include the following:
Human uses.
Some limpet species in this family are used as a food source in various countries.
A study of "Patella caerulea" found that this limpet reduced the cover of algae and barnacles on steel panels suspended in sea water in a commercial port, suggesting that the limpet could be used to inhibit fouling of ship hulls.
References.
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