Osteological peculiarities of Bufo brongersmai (Anura: Bufonidae) and their possible relation to life in an arid environment. Zoological Studies 48(1): 108-119. The morphology of selected isolated skeletal elements of the northwestern African endemic toad Bufo brongersmai Hoogmoed 1972 is herein described and compared to those of other Bufo species inhabiting the same area and Europe. The osteological morphology of this species clearly differentiates it from others within the genus, and several diagnostic osteological characters are added to the specific diagnosis. In particular, the presence in adult individuals of a rather-large maxillary fontanella, which late in ontogeny is reduced to a few foramina, has not been observed in other species. These fontanellae, as well as the fenestrations on the sphenethmoid, together with other osteological traits, suggest a significant degree of hypo-ossification. This seems likely related to the rapid larval development that allows B. brongersmai to achieve higher reproductive fitness than other species in the highly ephemeral waters of the rocky, arid environment it inhabits. Other peculiar osteological traits could be related to the exploitation of small crevices to protect adults from overheating and desiccation.