 Very little is known of the soft tissue of temnospondyls . A block of sandstone , described in 2007 from the Early Carboniferous Mauch Chunk Formation of Pennsylvania , included impressions of the bodies of three temnospondyls . These impressions show , when alive , they had smooth skin , robust limbs with webbed feet , and a ridge of skin on their undersides . Trackways referable to small temnospondyls have also been found in Carboniferous and Permian rocks . The trackways , called batrachichni , are usually found in strata deposited around freshwater environments , suggesting the animals had some ties to the water . 
 Very little is known of the soft tissue of temnospondyls . A block of sandstone , described in 2007 from the Early Carboniferous Mauch Chunk Formation of Pennsylvania , included impressions of the bodies of three temnospondyls . These impressions show , when alive , they had smooth skin , robust limbs with webbed feet , and a ridge of skin on their undersides . Trackways referable to small temnospondyls <a href='been_done' title='1'><mark>have</mark></a> also been found in Carboniferous and Permian rocks . The trackways , called batrachichni , are usually found in strata deposited around freshwater environments , suggesting the animals had some ties to the water . 
Very little is known of the soft tissue of temnospondyls . A block of sandstone , described in 2007 from the Early Carboniferous Mauch Chunk Formation of Pennsylvania , included impressions of the bodies of three temnospondyls . These impressions show , when alive , they had smooth skin , robust limbs witt webbed feet , and a ridge of skin on their undersides . Trackways referable to small temnospondyls done also been found in Carboniferous and Permian rocks . da trackways , called batrachichni , are usually found in strata deposited around freshwater environments , suggesting the animals had some ties to tdawater .