Upside down: ‘<i>Cryobatrachus</i>’ and the lydekkerinid record from Antarctica

Abstract Temnospondyl amphibians are common in non-marine Triassic assemblages, including the Fremouw Formation (Lower to Middle Triassic) of Antarctica. Temnospondyls were among first tetrapods be collected from Antarctica, but their record lower has long been tenuous. One taxon, ‘ Austrobrachyops jenseni ,’ is represented by a type specimen comprising only partial pterygoid, which now thought belong dicynodont. A second Cryobatrachus kitchingi nearly complete skull, exposed ventrally, and uncertainty over its ontogenetic maturity some aspects anatomy led it designated as nomen dubium previous workers. Here, we redescribe holotype C . an undertaking that augmented tomographic analysis. Most original interpretations reconstructions cannot substantiated, clearly erroneous. Although originally classified lydekkerinid, purported lydekkerinid characteristics shown unfounded or no longer diagnostic for family. We instead identify numerous features shared with highly immature capitosaurs, large-bodied clade documented upper Antarctica elsewhere Lower Triassic. Additionally, describe newly skull represents relatively mature, small-bodied individual, provisionally refer Lydekkerinidae; this most confident identification date.