Temnospondyls , like all amphibians , reproduced in aquatic environments . Most temnospondyls probably reproduced through external fertilization . Like most living frogs , female temnospondyls would have laid masses of eggs in water while males released sperm to fertilize them . Several fossils were described from the Early Permian of Texas in 1998 that may be egg masses of dissorophoid temnospondyls . They were the first known fossils of amphibian eggs . The fossils consist of small disks with thin membranes that are probably vitelline membranes and halo @-@ like areas surrounding them that are most likely mucous coatings . They are attached to plant fossils , suggesting that these temnospondyls laid eggs on aquatic plants much like modern frogs . The mucous membranes show that the eggs were laid by amphibians , not fish ( their eggs lack mucous ) , but the type of amphibian that laid them cannot be known because no body fossils are preserved with the eggs . The eggs are thought to be from dissorophoids because they are likely to be close relatives of modern amphibians , and probably had similar reproductive strategies . They are also the most common amphibians from the deposit in which the eggs were found .