Hyloxalus vertebralis

Hyloxalus vertebralis, also known by its vernacular name Boulenger's rocket frog, is a species of rocket frog native to the inter-Andean valleys and the foothills of the western Andes Mountains in central and southern Ecuador. The species is similar in coloration to H. subpunctatus, being walnut brown dorsally, mottled black and pale yellow laterally, and steel grey ventrally. H. vertebralis has not been observed in the wild since 1997 and is marked as critically endangered on the IUCN Red List.

Population decline
H. vertebralis was numerous in the region of Bosque Protector Mazán in the mid-to-late 1980s, particularly in 1986 and 1987. In subsequent years, the species' population rapidly declined. A survey conducted in 1995 was only able to identify one specimen; since 1997, no surviving individuals have been found.

While H. vertebralis was considered threatened by habitat loss prior to 1986, the IUCN attributed the rapid population decline to an outbreak of chytridiomycosis among the species. A 2004 assesement of the species estimated that at least 80% of the original population had been lost.