Tricladida is an order of the Turbellaria

Turbellaria

The Turbellaria are one of the traditional sub-divisions of the phylum Platyhelminthes , and include all the sub-groups that are not exclusively parasitic. There are about 4,500 species, which range from to in length...

, a group of free-living flatworms.

Tricladida (Lang, 1884) is characterized by triply branched intestine and anteriorly situated ovaries, next to the brain. Today it is split into three suborders, according to their phylogenetic relationships: Maricola, Cavernicola and Continenticola

Continenticola

Continenticola conforms a clade that includes the land planarians and the freshwater triclads .-Phylogeny:Phylogenetic tree after Carranza et al. 1998:...

. Formerly, the Tricladida was split according to habitats: Maricola, which is marine; Paludicola, which inhabits freshwater; and Terricola

Terricola

The Family Geoplanidae, common name Land planarians is an understudied but important group of flatworms that belong to the soil ecosystem....

, which is land-dwelling .

Phylogeny and taxonomy

Phylogenetic tree after Carranza et al. (1998):
Linnaean

Linnaean

Linnaean can refer to:*Carolus Linnaeus*Linnaean taxonomy*Linnaean enterprise*Linnean...

 ranks after Sluys et al., 2009:

• Order Tricladida
  • Suborder Maricola
    • Superfamily Cercyroidea
      • Family Centrovarioplanidea
      • Family Cercyridae
      • Family Meixnerididae
    • Superfamily Bdellouroidea
      • Family Uteriporidae
      • Family Bdellouridae
    • Superfamily Procerodoidea
      • Family Procerodidae
  • Suborder Cavernicola
    Cavernicola
    Cavernicola is a genus of assassin bugs in the family Reduviidae. They are endemic to the wild ecotopes of Panama and northern South America. Cavernicola species, as well as many other Reduviidae insects, are considered vectors of Trypanosoma cruzi, a known cause of Chagas disease.C...
    
    
    • Family Dimarcusidae
  • Suborder Continenticola
    Continenticola
    Continenticola conforms a clade that includes the land planarians and the freshwater triclads .-Phylogeny:Phylogenetic tree after Carranza et al. 1998:...
    
    
    • Superfamily Planarioidea
      • Family Planariidae
        Planariidae
        Planariidae is a family of Tricladida that inhabits the freshwater.The type genus is Planaria Müller, 1776.-Genera:Twelve genera of Planariidae are known:*Albiplanaria*Atrioplanaria*Crenobia*Galeocephala*Hymanella...
        
        
      • Family Dendrocoelidae
        Dendrocoelidae
        Dendrocoelidae is a family of freshwater tricladida flatworms.The largest triclad known belongs to this family, it's up to 40 cm in length and inhabits the Lake Baikal.Dendrocoelidae is the sister group of Planariidae.-Genera:...
        
        
      • Family Kenkiidae
    • Superfamily Geoplanoidea
      • Family Dugesiidae
        Dugesiidae
        Dugesiidae is a family of freshwater Tricladida distributed worldwide . According to molecular analyses, Dugesiidae is the sister group of land planarians.-Genera:Eleven Dugesiidae genera are known:* Bopsula* Cura* Dugesia...
        
        
      • Family Geoplanidae

External links

• land planarians on the UF
  University of Florida
  The University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
  
   / IFAS
  Institute of Food and Agricultural Sciences
  The University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information...
  
  Featured Creatures Web site