Palemys bowerbankii was a relatively large side-necked bothremydid turtle, with an elongated oval shell that could exceed 45 cm in length. Bothremydids were an old pleurodiran lineage with a long evolutionary history outside Europe; Palemys is important because it shows that one branch of that lineage persisted in Europe into the early Eocene rather than representing a newly arrived African immigrant.

Its shell construction indicates a strongly aquatic turtle. In the London Clay environment it probably inhabited coastal freshwater or brackish systems and could have entered estuaries, although its precise salinity tolerance cannot be demonstrated from the shell alone. Feeding evidence is absent; an opportunistic diet of aquatic invertebrates and other small food is a reasonable inference for a bothremydid of this size. The species is known chiefly from carapaces and plastra, including both juvenile and adult individuals.