Aculifera

Aculifera (older name: Amphineura) is a clade of molluscs incorporating those groups that have no conch or shell, that is, the Polyplacophora, Caudofoveata and Solenogastres.^[1] It is a sister group to the Conchifera. Monophyly of Aculifera is supported by fossil, anatomical and molecular studies.^[2]

Aculifera Temporal range: Cambrian Stage 4–Recent PreꞒ Ꞓ O S D C P T J K Pg N
A polyplacophoran (chiton)
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Clade:	Aculifera Hatschek, 1891
Classes
†Mattheviidae Polyplacophora Aplacophora

The oldest known aculiferan is Qaleruaqia, which was found in the Aftenstjernesø Formation in Greenland, which dates back to the Cambrian Stage 4.^[3]