Anomochilus is a genus of snakes, it is the only genus in the monogeneric family Anomochilidae and has three species classified within it. Members of the genus are known as anomochilids, or by the common names dwarf pipesnake, lesser pipesnake, and giant blind snake.[2][3] Initially created as Anomalochilus in 1890 for the species A. weberi, the genus was renamed in 1901 because the original name was already in use for a genus of beetles. Dwarf pipesnakes are small and cylindrical, with short, conical tails and small, rounded heads that are continuous with the neck. They have blackish to purplish-brown uppersides and dark brown or black undersides, with orange-red bands around the tail and a variety of pale markings on the snout and belly. All three species of dwarf pipesnake are endemic to Sundaland, where they are found on the Malay Peninsula and the islands of Sumatra and Borneo.
Adapted to living underground, dwarf pipesnakes inhabit leaf litter in lowland and montane rainforests at elevations of 220–1,513 m (722–4,964 ft). They are poorly studied and little is known about their diets and reproductive habits. They probably feed on earthworms, snakes, and legless lizards, and uniquely within their superfamily, lay eggs to give birth. Two species of dwarf pipesnake, A. weberi and monticola, are classified as being Data Deficient by the IUCN, while the third species, A. leonardi, is classified as being of Least Concern.
The genus Anomochilus[a] was erected by the Dutch herpetologist Theodorus Willem van Lidth de Jeude in 1890 as Anomalochilus for the species Anomalochilus weberi, which he described on the basis of a female specimen from Sumatra.[5] In 1901, the naturalist Charles Berg renamed the genus to Anomochilus, as the name Anomalochilus was already in use for a genus of beetles.[4] A second species of the genus, A. leonardi, was described by the British herpetologist Malcolm Arthur Smith in 1940 from two specimens collected in Pahang, Malaysia.[6] The third species in the genus, A. monticola, was described by the Indian herpetologist Indraneil Das and colleagues in 2008, based on specimens collected from Mount Kinabalu on Borneo.[7]
Anomochilus was initially described in the family "Tortriciidae",[b] which was later synonymized with the family Cylindrophiidae. Subsequently, it was moved to Aniliidae, before being placed in Uropeltidae by the American herpetologist Samuel Booker McDowell Jr. in 1975.[9] In 1993, the American herpetologist David Cundall and colleagues split the Uropeltidae into three families, reinstating Cylindrophiidae and moving Anomochilus into its own monogeneric family, Anomochilidae.[10] Subsequent genetic studies have shown that Cylindrophiidae is likely paraphyletic (not containing all the descendants of a common ancestor) with respect to Anomochilidae,[11] and a 2022 study recommended placing Anomochilus back in the former family.[12]
Anomochilus contains three species of pipesnake. All three species are known to live on the island of Borneo, which is presumed to be the center of diversification for the genus.[12] The genus is closely related to the family Cylindrophiidae, which it is sometimes placed in, and these two form a clade most closely related to the Uropeltidae. The following cladogram shows phylogenetic relationships of Anomochiliidae with other families, based on the 2022 study:[12]