December 20 , 2016:

New material from the Muschelkalk of Silesia, southern Poland, is described and attributed to Hemilopas mentzeli v. Meyer, 1851, a species previously considered a nomen dubium. It is here reinstated as a valid taxon on the basis of a newly presented neotype and specific diagnosis. A possible position of Hemilopas mentzeli in a phylogenetic tree of early diapsids, is discussed and its relationship with Saurosphargidae; a family of marine diapsids basal to Sauropterygia is hypothesized. A similar tooth morphology shared by different early diapsids is considered convergent.

Dawid Surmik (2016)
Hemilopas mentzeli, an enigmatic marine reptile from the Middle Triassic of Poland revisited.
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 282(2): 209-223
DOI: https://doi.org/10.1127/njgpa/2016/0614