Toothless bufonids with poison shoulders and a spare ovary
Bufonidae true toads exceed thirty-five genera and 570-plus species, the only anuran family whose members are all called toads. Toothless and warty, they wear parotoid glands behind the eyes that leak alkaloid toxins when stressed, and most adults hide a Bidder’s organ that can become an ovary.
Origins likely sit in South America after Gondwana’s split, with molecular clocks arguing Late Cretaceous dates around 78–99 million years ago or, alternatively, early Paleocene starts. Native to every continent except Australia and Antarctica, they occupy deserts to rainforests. Most lay paired egg strings that become tadpoles; Nectophrynoides and a few others skip free larvae or use internal fertilization rare among frogs.
Edentulism evolved in frogs more than twenty times, yet every bufonid lacks teeth—a thoroughness matched mainly by many microhylids. Bidder’s organs appear in males or females of nearly all genera except Melanophryniscus and Truebella. Internal fertilization is confirmed in Altiphrynoides, Nimbaphrynoides, and some Nectophrynoides, a short list beside Ascaphus and a few Eleutherodactylus.
From cane-toad notoriety to harlequin frog glitter, the family’s chemical shoulders and plastic life histories show how a South American radiation became the world’s default “toad” morph without ever needing a bite.
Paired egg strings in ponds remain the default reproductive image, yet live-bearing African genera rewrite the script with internal fertilization and miniature toadlets. Parotoid milky secretions vary from mild irritants to heart-stopping bufotoxins depending on species and predator. Tooth loss across the whole family hints at feeding styles that need crushing jaws less than sticky tongues. Global hitchhiking cane toads later showed how a South American body plan could overrun continents humans opened. Phylogenies by Portik, Papenfuss, Chan, and others keep rearranging Southeast Asian genera, yet the toothless, poison-shoulder body plan stays the family’s unmistakable signature worldwide.
Source: True toad
