Stephanian (stage) in the context of "Antennipatus"

Antennipatus montceauensis is an extinct species of onychophoran, a group colloquially known as velvet worms, from the Montceau-les-Mines lagerstätte of what is now France. The animal is the sole member of its genus and notably the oldest confirmed onychophoran fossil. While known of since the 1980s, Antennipatus was described almost 4 decades later in 2016. Currently, the animal has three described specimens with varying levels of preservation. All of are 305 million years old and date to the Stephanian stage of the Late Carboniferous.

Anatomically, Antennipatus resembles modern velvet worms. The animal had rings of dermal papillae along most of its body, with those on the antennae alternating between wide and narrow bands. On its underside, Antennipatus had a putative ventral mouth that preserved what were likely lip papillae. The animal had stubby legs, and on one specimen, definite slime papillae.