Invavita

Invavita piratica is an extinct, parasitic species of tongue worm, provisionally assigned to the order Cephalobaenida, from Herefordshire Lagerstätte, Ludlow-aged England. It possessed a head, a worm-like body, and two pairs of limbs.
The 425-million-year-old Silurian fossil holotype specimen was found still attached to its fossilised host, a specimen of the ostracod Nymphatelina gravida, at an undisclosed location in England. It is now in Oxford [University Museum of Natural History]. It was first described in the journal Current Biology in 2015.

Etymology

The generic name is a New Latin compound word combining "invasor" and "avitus," and roughly translates as "ancient intruder." The specific name refers to piracy; both names referring directly to the organism's obvious parasitic lifestyle.