**FIGURE 1.** Geographic distribution of the localities from western Mediterranean (circles), Balkans (stars), and western Anatolian (squares) basins. Dashed contours depicting the areas with Vallesian localities sampled. 1. Vallès-Penedès Basin (Santiga, Can Llobateres, Can Poncic); 2. Teruel Basin (Concud, El Arquillo); 3. Cabriel Basin (Venta del Moro); 4. Axios Valley (Pentalophos, Ravin de la Pluie, Ravin des Zouaves-5 and Dytiko sites); 5. Thessaly (Perivolaki); 6. Mesta Valley (Hadjidimovo); 7. Chalkidiki Peninsula (Nikiti-1 and Nikiti-2); 8. Biga Peninsula (Gülpınar); 9. Muğla Yatağan Basin (Şerefköy-2); 10. Samos Island (Mytilinii-A, Mytilinii-B).

**FIGURE 2.** Bivariate plot showing the mean and the standard error of the mean for the complexity (Asfc) and anisotropy (epLsar) variables. The symbol type (circle/square) represents the region, the filling of the symbol differentiates between hipparionin size types, and the color if they are from Vallesian (grey) or Turolian (black) assemblages. Extant wild *Equus africanus asinus *(A) and *Equus quagga burchelli *(B) are included for comparison.

**FIGURE 3.** Bar charts with the mean and the standard error of the mean of the four DMT parameters for each hipparionin group. Small-sized forms shown in light grey, larger ones in dark grey. **A:** Asfc. **B:** epLsar.** C:** HAsfc. **D:** Tfv

**FIGURE 4.** Mean values and confidence intervals (2× standard error of the mean) of the microwear Principal Component 1 for each hipparionin group. Dashed lines used for small-sized groups and continuous for large-sized. Grey color represents Vallesian hipparionins and black color the Turolian hipparionins.