Oldest temnospondyl
The oldest fossil of a temnospondyl that's referred to a particular genus is Balanerpeton woodi, from the Mississippean of Scotland (Milner & Sequeira, 1994). Balanerpeton is within the temnospondyl family Dendrerpetidae, which includes the slightly younger Dendrerpeton and Dendrysekos from the Joggins Fossil Cliffs in Nova Scotia. Werneburg et al. (2019) recently reported some fragmentary temnospondyl bits from the same time interval in Germany. This material could only be tentatively identified as a possible dvinosaur.