The Malaysian Rail-babbler (Eupetes macrocerus) is a strange rail-like pied inhabitant of the floor of primary forest in the Malay Peninsula and Sumatra (the nominate subspecies macrocerus), as well as Borneo (ssp. borneensis), distantly related to Australian crow-like birds. Its population has greatly decreased because much of the lowland primary forest has been cut, and secondary forests usually have too dense a bottom vegetation or do not offer enough shade to be favourable for the species. However, it is locally still common in logged forest or on hill-forest on slopes, and probably not in immediate danger of extinction.
Opinions on the correct taxonomic placement for the rail-babbler have differed. Until recently, it had been regarded as being related to a group which included the quail-thrushes and whipbirds, and placed in the family Cinclosomatidae (previously in Orthonychidae when the members of the Cinclosomatidae were regarded as belonging with the logrunners).
However, Serle (1952) had pointed out a number of similarities between this species and the two species of rockfowl (Picathartes): similar proportions, the position of the nostrils, the shape of the forehead, and that of the tail. Based on molecular studies, Jønsson et al (2007) argues that this is closer to the correct position for this species; the rail-babbler is most closely related to the rockjumpers, another early branch of the oscine passerines. As such, it is more correctly placed in a monotypic family, Eupetidae. This is one of only three bird families restricted to the Oriental zoogeographical region.