Yongjiacaris [SEP] parent taxon
, conglomerate, and rhyolite, while the Showchang Formation is dominantly sandstone and mudstone. The types of plants present in the C Member and the Showchang Formation (relatively abundant ferns and Bennettitales, rare members of the Ginkgoaceae) and characteristics of the plants, such as leaf form and cuticle thickness, indicate a relatively hot and dry climate. The two rock units have fossil assemblages including plants, charophytes, bivalves, ostracods, conchostracans, and insects.
While other genera from the family Palaemonidae are known from the Aptian age in
Yongjiacaris
Yongjiacaris zhejiangensis is an extinct species of shrimp, and the only species in the genus "Yongjiacaris". "Yongjiacaris" represents the second report of freshwater caridean shrimp from the Mesozoic.
The name of the genus "Yongjiacaris" refers to Yongjia County, in the Zhejiang Province of China, while the species name "Y. zhejiangensis" is derived from the province name. "Yonjiacaris" was formally described by Alessandro Garassino, Shen Yanbin, Frederick R. Schram, and Rod S. Taylor in 2002. It is described