BARBOUROFELIDAE TO

Morlo, Michael, Peigné, Stéphane & Nagel, Doris, 2004, A new species of Prosansanosmilus: implications for the systematic relationships of the family Barbourofelidae new rank (Carnivora, Mammalia), Zoological Journal of the Linnean Society 140 (1), pp. 43-61 : 56-57

RELATIONSHIPS OF BARBOUROFELIDAE TO FELIDAE

Reasons for excluding the Barbourofelidae from the Nimravidae have been provided by previous authors ( Neff, 1983; Morales et al., 2001). The differences between Barbourofelidae and Felidae are less obvious. Following Tedford (1978), the barbourofelids have been excluded from the Felidae mainly due to their peculiar auditory structure. Their assignment has, however, recently been reaffirmed ( Morales et al., 2001). As a result, we address the anatomical characters involved in this relationship in greater detail.

While Sansanosmilus and Barbourofelis are easy to distinguish from Felidae by dental anatomy, the earliest barbourofelids ( Prosansanosmilus , Afrosmilus , Ginsburgsmilus ) are similar to Felidae in this respect, as shown by the cladistic analysis. Some dental characters shared by Barbourofelidae and Felidae (e.g. the presence of accessory cusps on the premolars) are, however, also present in early aeluroids such as Stenoplesictis , Stenogale or Viretictis ( Hunt, 1998a; de Bonis, Peigné & Hugueney, 1999; Peigné & de Bonis, 1999). These may therefore be common aeluroid characters rather than evidence for the placement of barbourofelids within Felidae . An upper carnassial with a parastyle and a posteriorly located protocone are common to Barbourofelidae and Felidae , although not exclusive to these two families. Other dental apomorphies of the Barbourofelidae are not present in Felidae and show an early trend towards a different adaptation, in particular, the markedly transversely compressed upper canines with crenulations and vertical grooves; the absence of P1/, P/1 and M/2; a lower carnassial with a tall protoconid, and an extremely small talonid which is markedly more reduced than the metaconid.

Although dental characters are consistent with the hypothesis that Barbourofelidae may be included in Felidae , fundamental differences in the mandible, such as the angular chin or the curved mandibular body, and, in particular, the auditory region provide strong support for not doing so. The basicranial anatomy of the Barbourofelidae is documented in S. palmidens (MN 6, ~13.5 Myr) and Barbourofelis . It differs not only from that of the first true felid Proailurus , but also from that of other early aeluroids such as Stenoplesictis . In barbourofelids, the external auditory meatus is wider than the auditory notch. The fusion of the elements making up the bulla has obviously proceeded further in barbourofelids, since it is not possible to distinguish the contribution of each element. The presence of a horizontal proseptum in the anteromedial corner of the bulla is unique among Carnivora and can be regarded as an autapomorphy of the Barbourofelidae .

Two other skull characters, both symplesiomorphies with respect to Nimravidae s.s. (see above), may distinguish the Barbourofelidae from the Felidae , although they remain to be confirmed in early barbourofelids: the shortening of the palate and the posteriorly converging lateral walls of the nasopharynx.

Due to the lack of basicrania, dental evidence alone places the plesiomorphic genera Prosansanosmilus , Ginsburgsmilus , Afrosmilus and Syrtosmilus in the Barbourofelidae . The similarity to the dentition of early felids, as demonstrated by, for example, the previous assignment of Afrosmilus to Felidae (Schmidt- Kittler, 1987) or the misinterpretation of P. eggeri as Pseudaelurus , is supported by the cladistic analysis. As a result, dental evidence alone would allow inclusion of Barbourofelidae as a subfamily in Felidae , as has been done by Morales et al. (2001), but doing so clearly falsifies the hypothesis that Barbourofelidae are included in Nimravidae s.l. The other anatomical differences, especially the unique basicranial morphology of barbourofelids, however, warrant the distinction of a separate family Barbourofelidae , sister group to Felidae and separate from Nimravidae s.s.