Acernaspis

Acernaspis is an extinct genus of trilobite that is known from the Silurian. It contains two species, A. elliptifrons, and A. salmoensis. It is sometimes found preserved in burrows of various forms, sometimes in association with multiple moults, suggesting that it used tunnels as refuges whilst in its vulnerable moulting stage.^[1]

Acernaspis
Acernaspis orestes inside burrow,[1] Jupiter Formation, Anticosti Island, Quebec.
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Clade:	†Artiopoda
Class:	†Trilobita
Order:	†Phacopida
Family:	†Phacopidae
Genus:	†Acernaspis Campbell, 1967
Species
Acernaspis orestes Billings, 1860 type species = Phacops orestes, A. mimica, A. superciliexcelsis[2]
Synonyms
Eskaspis Murphycops