The extant native carnivores of Madagascar form a monophyletic group and together comprise the family Eupleridae (there are also three carnivore species that have been introduced to Madagascar by humans: the domestic dog, the Wildcat (introduced in the 19th century and not uncommon in natural forest habitats), and the Small Indian Civet (generally found in heavily degraded and open edges or at the forest edge). Goodman (2009) recognized 8 euplerid species in seven genera and notes that there is at least one more form that is likely to be recognized as a distinct species.
The euplerids have caused considerable taxonomic confusion over the years as a result of what is now believed to be striking convergent evolution between this highly isolated lineage in Madagascar (currently separated from the mainland by around 400 km of open water) and the evolution of the carnivore lineage in other parts of the world. This convergence in features resulted in various members of the Madagascar carnivore lineage resembling cats (family Felidae), civets (family Viverridae), or mongooses (family Herpestidae) from "off-island" as they adapted to fill similar ecological niches (similar striking examples can be seen in the similarities between various species in the Australian marsupial lineage and "ecological equivalents" evolving elsewhere). The recent molecular phylogenetic data indicating that all the Madagascar carnivores have a single carnivore ancestor rather than representing multiple mainland lineages implies a scenario requiring just one ancient colonization rather than three. Unfortunately, there are no known shared derived morphological characters (i.e., "synapomorphies")uniting this group, which would support the monophyly indicated by the molecular data. The sister group to the Eupleridae is the Herpestidae; sister to (Eupleridae + Herpestidae) is Hyaenidae (Agnarsson et al. 2010; Eizirik et al. 2010).
Goodman (2009) reviewed the history of the taxonomic treatment of Madagascar's native carnivores.The largest and best known living euplerid, the Fosa (Cryptoprocta ferox), is nearly the size of a small Puma and was at one time believed to be a felid (at other times it was placed in its own family or considered to be a viverrid or herpestid). The Spotted Fanaloka (Fossa fossana) and Falanouc (Eupleres goudotii) were believed to be viverrids and the Ring-tailed Vontsira (Galidia elegans), Broad-striped Vontsira (Galidictis fasciata), Grandidier's Vontsira (Galidictis grandidieri), Brown-tailed Vontsira (Salanoia concolor), and Narrow-striped Boky (Mungotictis decemlineata) were all believed to be herpestids. Today, species in the first three genera above are included in the subfamily Euplerinae whereas the mongoose-like species in the latter four genera are placed in the subfamily Galidiinae. By the middle of the 19th century, six of the eight euplerids had been described. The Narrow-striped Boky was described in 1867 and Grandidier's Vontsira in 1986 (this latter species has a conservation status of Endangered, with a range of less than 500 km2 that is essentially a single location in extreme southwestern Madagascar). The Giant Fosa (Cryptoprocta spelea) is known only from subfossil remains and apparently went extinct within the past few thousand years.
The basic biology of some euplerids, such as the vontsiras, remains almost unknown. Conservation assessments are difficult for most euplerids due to a dearth of information, but the enormous loss of forest habitat in Madagascar during the latter half of the 20th century surely had a negative impact impact on all euplerid species, although some more than others. In addition to threats from habitat loss, most (possibly all) euplerids are consumed as bushmeat. They are all generally viewed by local people as vermin and blamed for preying on domestic animals, especially fowl, although much of this predation can actually be attributed to the introduced Small Indian Civet.