The Permian and Triassic history of the ostracod genus Liuzhinia

The ostracod genus Liuzhinia has been reported from Permian and Triassic marine deposits mainly from the Tethyan area but its classification and history remain obscure. Here we report on the discovery of a rare steinkern of Liuzhinia antalyaensis from the Early Triassic of South China bearing the first known adductor muscle scars, allowing for first insights into its supra-generic classification. We demonstrate that Liuzhinia does not belong to Bairdiidae and propose that the observed muscle scars could illustrate ancestral characters of Paracyprididae or Bythocyprididae. We summarize the diversity of Liuzhinia through time, including the newly described Liuzhinia phetchabunensis Forel & Chitnarin sp. nov. from the Middle Permian of central Thailand, and discuss its geographical distribution and environmental preferences over its stratigraphical range.