An extinct creature that resembled a cross between an earthworm and a millipede is the oldest known segmented animal able to move under its own power
Source:
https://www.newscientist.com/article/2215291-540-million-year-old-worm-was-first-segmented-animal-that-could-move/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home