fossas, falanoucs, and bokibokys

Traditionally, the small endemic carnivores of Madagascar were variously placed with the viverrids (genets and kin) (Albignac 1972) or sometimes herpestids (mongooses) based on recognizable morphological traits. Members of the subfamily Galidiinae are very mongoose-like (sometimes called Malagasy mongooses) while the Euplerinae are genet-like (especially Fossa fossana, sometimes called the Malagasy civet). There were early indications this was not quite accurate, as when the fossa, Cryptoprocta ferox, showed molecular affinities to the Herpestidae, but had the auditory structure typical of viverrids (Veron and Catzeflis 1993). Genetic investigation eventually determined that all endemic Madagascan carnivores descended from a single introduction, and had a herpestid ancestor (Yoder et al. 2003). Biologists explain the similarities of some genera to viverrids as simply biological convergence (Gaubert et al. 2005).

We only have subfossils of the Family Eupleridae, as no pre-Holocene fossils have been discovered. So, phylogenetic analysis must rely on genetics of the known species. Only one extinct species is recognized, the giant fossa (Cryptoprocta spelea). This was a much larger fossa, one that possibly weighed up to twice what a modern adult fossa weighs (large males can get to about 8.5 kg). It likely preyed opportunistically on the larger, now extinct, subfossil lemurs, and appears to have been capable of preying on lemurs up to 80-85 kg. Evidence of predation by the giant fossa has been found in most of the extinct lemurs (Goodman et al. 2004; Meador et al. 2019). Interestingly, there are still stories of the fosabe (big fosa), and one biologist believes that he may have seen such an animal, “twice the size and much darker than the common fossa” (Nomenjanahary et al. 2019).

There are seven genera within the Eupleridae, and about nine living species (depending on author). The subfamily Galidiinae is monophyletic: “Galidia is the first to branch off, then Galidictis, and our results show that Salanoia is sister to Mungotictis” (Veron et al. 2017). Fossa and Eupleres form a sister clade to the Galidiinae, and that grouping forms a sister clade to Cryptoprocta (Nyakatura and Bininda-Emonds 2012; Zhou, Wang, and Ma 2017).