Syncaris is a genus of shrimp, containing only two species: the endangered California freshwater shrimp, Syncaris pacifica, and the extinct Pasadena freshwater shrimp, Syncaris pasadenae.[1] This genus is one of only two genera of freshwater Atyid shrimp found in North America, with the other being the genus Palaemonias, which contains two endangered, cave-dwelling shrimp species.[2] The genus Syncaris may have arisen during the Mesozoic, with the family Atyidae likely being of Jurassic origin.