Three of the seven currently recognized bisexual polyploid anuran species have morphologically very similar diploid “cryptic species” counterparts. The North American diploidtetraploid cryptic species pair Hyla chrysoscelis and H. versicolor is analyzed and compared with diploid and tetraploid populations of the South American nominal species Odontophrynus americanus. It is postulated that, through an intermediate triploid stage, tetraploidy could arise independently in diploid species by way of suppressed maturation in oöcytes. Tetraploid populations arising sympatrically from diploid species may maintain their integrity bio-acoustically. Polyploidization in the Anura is an important evolutionary mechanism and may prove to be quite wide spread when species are carefully examined on a population level.