A revision of the trionychid turtle Procyclanorbis sardus Portis, 1901 from the late Miocene of Sardinia (Italy)

Procyclanorbis sardus Portis, 1901 is the first fossil trionychid turtle described from Sardinia. This lateMiocene taxon was originally considered to have affinities with the African and southern Asian cyclanor-bines. We here redescribe in detail the holotype specimen of this species, which has suffered severedegradation since its original publication. A comparison between the original state of the fossil and itscurrent state of preservation is provided. On the basis of its anatomy, affinities of Procyclanorbis sarduswith cyclanorbines are discarded and this taxon is demonstrated to be an indeterminate pan-trionychine.The distribution of fossil trionychids in the Mediterranean Islands is also discussed.