They are related to the kingfishers, bee-eaters and rollers. They most resemble the latter group, and are sometimes considered a sub-family of the true rollers. They share the generally crow-like size and build of that group, and also hunt large insects and reptiles. They are more terrestrial than the Coracidae species, and this is reflected in their longer legs and shorter, more rounded wings.
They lack the highly colourful appearance of the true rollers, and are duller in appearance. They are much more elusive and shy than their relatives, and are normally difficult to find in the Madagascan forests. Often the hooting breeding call is all that betrays their presence.
These birds nest as solitary pairs in holes in the ground which they excavate themselves, unlike the true rollers, which rarely nest in ground holes and even then do not dig their own nests.
There are five species in three genera:
- Short-legged Ground-Roller, Brachypteracias leptosomus
- Scaly Ground-Roller, Brachypteracias squamigera
- Pitta-like Ground-Roller, Atelornis pittoides
- Rufous-headed Ground-Roller, Atelornis crossleyi
- Long-tailed Ground-Roller, Uratelornis chimaera