The fossil taxon ''Priapulites'' from the Mazon Creek is the earliest-known crown-group priapulid, and is closely related to the
Priapulidae
Priapulidae is the canonical family of priapulid
Priapulida (priapulid worms, from Gr. πριάπος, ''priāpos'' 'Priapus' + Lat. ''-ul-'', diminutive), sometimes referred to as penis worms, is a phylum of unsegmented marine worms. The name ...
.
A detailed description was conducted by Simon Conway Morris
References
Priapulida
Prehistoric protostome genera
†Priapulites
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