A new turtle from the Early Cretaceous (Aptian) Jiufotang Formation of western Liaoning, China, Perochelys lamadongensis, gen. et sp. nov., represents the first species of soft-shelled turtle from the Jehol Biota. The new taxon is diagnosed by the combination of the following characters: nuchal bone about five times wider than long; preneural absent; reversal of the orientation in the neural series at neural V; neural series fully separates costal series; costal VIIIs reduced; plastral callosities poorly developed and poorly sculpted; postorbital bar narrow, around one-fourth of orbit diameter; jugal contacting squamosal; foramen jugulare posterius separated from fenestra postotica; neural spines weakly developed on anterior cervicals; and phalangeal formula for pes 2-3-3-4-?. High levels of homoplasy make the phylogenetic relationships of the new taxon difficult to assess, and the possibility therefore exists that Perochelys lamadongensis either represents a stem or a crown trionychid. This phylogenetic uncertainty confirms that the skeletal morphology of trionychids has remained virtually unchanged for the last 120 million years.
http://zoobank.org/urn:lsid:zoobank.org:pub:1FE50A16-5FE6-4DEE-B839-CE2A52038F55