Ellesmerocerida

Cladus: Eukaryota
Supergroup: Opisthokonta
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Spiralia
Cladus: Lophotrochozoa
Phylum: Mollusca
Classis: Cephalopoda
Subclassis: Nautiloidea
Ordo: †Ellesmerocerida
Genera: Acaroceras ...

References

* Chen, J-Y.; Zou, X-P.; Chen, T-E.; Qi, D-L. 1979: Late Cambrian Ellesmerocerida (Cephalopoda) of north China. Acta palaeontologica sinica, 18: 103-124. [In Chinese with English abstract]