Figure 1 in Diegoaelurus, a new machaeroidine (Oxyaenidae) from the Santiago Formation (late Uintan) of southern California and the relationships of Machaeroidinae, the oldest group of sabertooth mammals

Figure 1 Distribution of North American representatives of Machaeroidinae. Light blue and green indicate basins producing early and middle Eocene machaeroidines, respectively. Note that while the Bridger Basin has produced several specimens of early Eocene Machaeroides eothen, USNM 173514 and AMNH FM 12083 are earliest middle Eocene. Basin outlines adapted from Dickinson et al. (1988) and Tomiya et al. (2021). Full-size DOI: 10.7717/peerj.13032/fig-1