This is a nice sample of Cambrian Chinese Trilobite coming from Shandon City. Damesellidae is a family of odontopleurid trilobites found in Middle to Late Cambrian  strata, primarily in China. here a nice example on sale of this elusive trilobite.
 
Damesella paronai
middle Cambrian
Drepanuridae Paronai zone
Kushanian Age
Kushan formation
Laiwu City
Shandon City
CHINA