Belongs within: Euarthropoda.
The Tantulocarida are a group of minute marine crustaceans ectoparasitic on other crustaceans: they have been recorded from copepods, cumaceans, isopods, ostracods and tanaids (Boxshall 1988). Other than paired antennules at one stage of the life cycle, tantulocaridans completely lack cephalic appendages (Martin & Davis 2001).
<==Tantulocarida | i. s.: Stygotantulus stockiMD01 |--DoryphallophoridaeMD01 |--OnceroxenidaeMD01 |--MicrodajusA99 [MicrodajidaeB88] | `--M. langiA99 |--Basipodella [Basipodellidae]B88 | |--B. atlanticaB88 | `--B. harpacticolaB88 `--DeoterthridaeB88 |--Austrotantulus Boxshall 1988B88 | `--*A. lincolni Boxshall 1988B88 `--DeoterthronB88 |--*D. dentatumB88 |--D. aselloticolaB88 |--D. harrisoniB88 `--D. megacephalaB88
*Type species of generic name indicated
References
[A99] Ax, P. 1999. Das System der Metazoa II. Ein Lehrbuch der phylogenetischen Systematik. Gustav Fisher Verlag: Stuttgart (translated: 2000. Multicellular Animals: The phylogenetic system of the Metazoa vol. 2. Springer).
[B88] Boxshall, G. A. 1988. A new genus of tantulocaridan (Crustacea: Tantulocarida) parasitic on a harpacticoid copepod from Tasmania. Bulletin of the British Museum (Natural History), Zoology series 54 (6): 271–274.
[MD01] Martin, J. W., & G. E. Davis. 2001. An updated classification of the Recent Crustacea. Natural History Museum Los Angeles County, Science Series 39: 1–124.