Average Frontation Angle for Five Species, by Family, Habitat, and Preferred Substrate
| Species | Family | Habitat | Preferred substrate | Frontation angle () |
|---|---|---|---|---|
| Vulpes lagopus | Canidae | open | terrestrial | 54.89 |
| Nyctereutes procyonoides | Canidae | closed | arboreal | 56.51 |
| Lynx lynx | Felidae | closed | terrestrial | 65.67 |
| Leptailurus serval | Felidae | open | terrestrial | 65.80 |
| Leopardus wiedii | Felidae | closed | arboreal | 67.61 |
By examining trait distributions across phylogenetic lineages, evolutionary biologists can determine whether trait similarities result from shared ancestry, leading to consistent presence of the trait among closely related species, or from convergent evolution under similar selective pressures, leading to the independent appearance of the trait in more distantly related species occupying similar ecological niches. Hypothesizing that orbit (eye socket) orientation in the families Canidae and Felidae (both within the order Carnivora) is primarily driven by the latter mechanism, a researcher measured frontation angles—the extent to which orbits face downward or upward—in felid and canid species occupying various habitats and preferring different substrates.