Enoplus meridionalis (Dujardin 1845; Steiner 1921) is one genus of extant nematode, a clade of worm that produces slime trails as it travels, is found everywhere on Earth, from mountains to deep seas. Sizes range from less than a millimeter to 1.25m. Typical size is <2.5mm. No head or notochord is present. Eversible teeth, similar to those in hagfish, are present. A post-anal tail produces adhesive. Compare to Myxine, the hagfish, below. More information here.

This is the outgroup taxon for the LRT.

Branchiostoma lanceolatus (originally Amphioxus lanceolatus Pallas 1774) is the extant lancelet, or headless fish. It probably originated in the Early Cambrian or earlier. This colonial, soft-bodied, tailess, headless, filter feeder burrows tail first, feeding on plankton that drifts by. Juveniles are more mobile, swimming to new feeding sites.

This is the outgroup taxon for the LRT.