Thoracica is a superorder of crustacean

Crustacean

Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

s which contains the most familiar species of barnacle

Barnacle

A barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...

s found on rocky coast

Coast

A coastline or seashore is the area where land meets the sea or ocean. A precise line that can be called a coastline cannot be determined due to the dynamic nature of tides. The term "coastal zone" can be used instead, which is a spatial zone where interaction of the sea and land processes occurs...

s, such as Semibalanus balanoides

Semibalanus balanoides

Semibalanus balanoides is a common and widespread boreo-arctic species of acorn barnacle. It is common on rocks and other substrates in the intertidal zone of north-western Europe and both coasts of North America.-Description:...

and Chthamalus stellatus

Chthamalus stellatus

Chthamalus stellatus, common name Poli's stellate barnacle, is a species of acorn barnacle common on rocky shores in South West England, Ireland, and Southern Europe. It is named after Giuseppe Saverio Poli.-Description:...

. They have six well-developed limbs, and may be either stalked or sessile. The carapace is heavily calcified. The group includes free-living and commensal species.

Classification

This article follows Martin and Davis in placing Thoracica as a superorder of Cirripedia and in the following classification of thoracicans down to the level of families:

Superorder Thoracica Darwin, 1854

• Order Pedunculata Lamarck, 1818
  • Suborder Heteralepadomorpha Newman, 1987
    • Anelasmatidae Gruvel, 1905
    • Heteralepadidae Nilsson-Cantell, 1921
    • Koleolepadidae Hiro, 1933
    • Malacolepadidae Hiro, 1937
    • Microlepadidae Zevina, 1980
    • Rhizolepadidae Zevina, 1980
  • Suborder Iblomorpha Newman, 1987
    • Iblidae Leach, 1825
  • Suborder Lepadomorpha Pilsbry, 1916
    • Lepadidae
      Lepadidae
      Lepadidae is a family of goose barnacles, erected by Charles Darwin in 1852. It contains the three genera Lepas, Conchoderma and Dosima....
      
       Darwin, 1852
    • Oxynaspididae Gruvel, 1905
    • Poecilasmatidae Annandale, 1909
  • Suborder Scalpellomorpha Newman, 1987
    • Calanticidae Zevina, 1978
    • Lithotryidae Gruvel, 1905
    • Pollicipedidae
      Pollicipedidae
      Pollicipedidae is a family of goose barnacles....
      
       Leach, 1817
    • Scalpellidae Pilsbry, 1907
• Order Sessilia
  Sessilia
  Sessilia is an order of barnacles, comprising the barnacles without stalks, or acorn barnacles. They form a monophyletic group and are probably derived from stalked barnacles. The order is divided into three suborders. Brachylepadomorpha contains a single family, Neobrachylepadidae, while...
  
   Lamarck, 1818

• • Suborder Brachylepadomorpha Withers, 1923
    • Neobrachylepadidae Newman & Yamaguchi, 1995
  • Suborder Verrucomorpha Pilsbry, 1916
    • Neoverrucidae Newman, 1989
    • Verrucidae Darwin, 1854
  • Suborder Balanomorpha
    Balanomorpha
    Balanomorpha is a suborder of barnacles, containing familiar acorn barnacles of the seashore. It contains the following families:*Archaeobalanidae Newman & Ross, 1976*Balanidae Leach, 1817*Bathylasmatidae Newman & Ross, 1971*Catophragmidae Utinomi, 1968...
    
     Pilsbry, 1916
    • Superfamily Chionelasmatoidea Buckeridge, 1983
      • Chionelasmatidae Buckeridge, 1983
    • Superfamily Pachylasmatoidea Utinomi, 1968
      • Pachylasmatidae Utinomi, 1968
    • Superfamily Chthamaloidea Darwin, 1854
      • Catophragmidae Utinomi, 1968
      • Chthamalidae
        Chthamalidae
        Chthamalidae is a family of barnacles of the order Sessilia, containing the following genera:*Chinochthamalus Foster, 1980*Chthamalus Ranzani, 1817*Euraphia Conrad, 1837*Nesochthamalus Foster & Newman, 1987...
        
         Darwin, 1854
    • Superfamily Coronuloidea Leach, 1817
      • Chelonibiidae Pilsbry, 1916
      • Coronulidae Leach, 1817
      • Platylepadidae Newman & Ross, 1976
    • Superfamily Tetraclitoidea Gruvel, 1903
      • Bathylasmatidae Newman & Ross, 1971
      • Tetraclitidae Gruvel, 1903
    • Superfamily Balanoidea Leach, 1817
      • Archaeobalanidae
        Archaeobalanidae
        Archaeobalanidae is a family of barnacles of the order Sessilia.-Taxonomy:*Subfamily Acastinae**Genus Acasta Leach, 1817**Genus Conopea Say, 1822*Subfamily Archaeobalaninae**Genus Chirona Gray, 1835**Genus Solidobalanus...
        
         Newman & Ross, 1976
      • Balanidae
        Balanidae
        Balanidae is a family of barnacles of the order Sessilia.- Genera :* †Alessandriella Carriol, 2001* Amphibalanus Pitombo, 2004* Arossia Newman, 1982* Austromegabalanus Newman, 1979* Balanus Da Costa, 1778* †Concavus Newman, 1982...
        
         Leach, 1817
      • Pyrgomatidae Gray, 1825