Some of the most poorly known snakes in the world, the three species of dwarf pipesnakes were discovered in 1890, 1940, and 2008. Collectively they are represented by fewer than twenty preserved museum specimens and photographic vouchers. Found in Sumatra, Borneo, and peninsular Malaysia, dwarf pipesnakes are small (< 40 cm), shiny, dark-colored snakes with bright yellow or white spots and a bold red band around their blunt tails. They have few specialized head scales, no chin groove, and mostly undifferentiated ventral scales. In addition, dwarf pipesnakes are unique in having lost their left lung entirely, a structure that is vestigial, but still present, in most other snakes. Dwarf pipesnakes have 3 teeth in each upper jaw, 5 in each lower jaw, and 0 on their pterygoid and palatine bones. They lay eggs and probably spend most of their time underground. Our understanding of their evolutionary history is limited because we have so few specimens and very little of their DNA has been sequenced. Several recent analyses have suggested that they are nested within another family, Cylindrophiidae ("Asian pipesnakes"), which they resemble morphologically in some respects and with which they might be merged in the near future.
A blog about snake natural history, ecology, and evolution