Enoplia

Enoplians are characterized by amphids shaped like ovals, stirrups, or pouches. Their bodies are smooth, without rings or lines. The esophagus is cylindrical and glandular.^[1]

Lorenzen described two orders, Enoplida and Trefusiida, in the 1980s based on morphology. With the advent of phylogenetic analysis, a reorganisation has been necessary, moving the Triplonchida here to create three orders and expanding it.^{[1][2] [3]}

The orders are distinguished mainly by habitat type.^[4][3]

• Enoplida Filipjev, 1929 – nematodes of marine and brackish water habitat, carnivorous or feed on diatoms and other algaes
• Triplonchida Cobb, 1920 – terrestrial nematodes, including some plant parasites
• Trefusiida Lorenzen, 1981

Enoplia is regarded as the earliest nematode branch, according to recent phylogenetic analysis.^[5] Enoplia is mentioned as a sister clade to Dorylaima and Chromadoria.^[5][6]