 <unk> , like all amphibians , reproduced in aquatic environments . Most <unk> probably reproduced through external fertilization . Like most living frogs , female <unk> 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 <unk> <unk> . They were the first known fossils of amphibian eggs . The fossils consist of small disks with thin membranes that are probably <unk> membranes and halo @-@ like areas surrounding them that are most likely mucous coatings . They are attached to plant fossils , suggesting that these <unk> 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 <unk> 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 . 
