Figure S1. Profiles of Equid crania. A: E. (Equus) caballus, MS 96872; B: Plesippus shoshonensis, LACM 210-17047; C: Allohippus vireti, QSV 240; Figure S2. Schematic occlusal view of an Equus cranium. 1: basilar length. 2: overall palatal lengh. 2-5: palatal length sensu stricto. 3: vomerine length. 4: post-vomerine length. 5. muzzle length. Measurements defined in Eisenmann 1986 [17]; Figure S3. Occlusal views of upper cheek teeth of E. cf. suessenbornensis. A: IQW S 1964/1182, left P3 or P4; B: IQW Süss. 7189, left P3 or P4; C: IQW Süss. 5617, left P4 or M1; D: IQW Süss. 7222, left P3 or P4; E: IQW Süss. 9230, left P3 or P4; F: IQW Süss. 6584, left P4 or M1; G: IQW Süss. 9264, right P3 or P4; H: IQW Süss. 9260, right P3 or P4; Figure S4. Occlusal views of lower cheek teeth of E. cf. suessenbornensis. A: IQW Süss. 6448, right P3 or P4; B: IQW Süss. 6222, left P3 or P4; C: IQW Süss. 6566, left P4 or M1; D: IQW Süss. 7204, left M1 or M2; Figures S5 to S14 collect the pictures and captions published by Reichenau [106] for ‘Hippotigris altidens’ and photographs and accession numbers of the teeth when they could be traced in the Institut von Quartär Paläontologie collections in Weimar; Figure S15. Occlusal views of upper cheek teeth of E. cf.  wuesti. All the accession numbers should be prefixed by IQW S; Figure S16. Occlusal views of lower cheek teeth of E. cf.  wuesti. All the accession numbers should be prefixed by IQW; Figure S17. Pictures and captions published by Reichenau [106] for Hippotigris marxi and photographs and accession numbers of the teeth when they could be traced in the Institut von Quartär Paläontologie collections in Weimar; Figure S18. Occlusal views of upper cheek teeth of E. marxi. All the accession numbers should be prefixed by IQW S. IQW S 3225 to S HA: Premolars. IQW S 228 to 7297: Molars; Figure S19. Occlusal views of lower cheek teeth of E. marxi. All the accession numbers should be prefixed by IQW S. IQW S 851 to 14461: Premolars. IQW S 886 to no number: Molars; Figure S20. Simpson's diagrams of Dmanisi slender metacarpals. 1: Maximal length. 3: Breadth at the middle of the diaphysis. 4: Depth of the diaphysis at the same level. 5: Proximal breadth. 6: Proximal depth. 10: Distal supra-articular breadth. 11: Distal articular breadth. 12: Depth of the sagittal crest. 13: Least depth of the medial condyle. 14: Greatest depth of the medial condyle; Figure S21. Simpson's diagrams of Dmanisi Dm70/34.3A4.45 and Dm8/151.1/A4.26 (probably juvenile)  metacarpals.1: Maximal length. 3: Breadth at the middle of the diaphysis. 4: Depth of the diaphysis at the same level. 5: Proximal breadth. 6: Proximal depth. 10: Distal supra-articular breadth. 11: Distal articular breadth. 12: Depth of the sagittal crest. 13: Least depth of the medial condyle. 14: Greatest depth of the medial condyle; Figure S22. Simpson's diagrams of Dmanisi metacarpals from Layers II, III, and Stratum B. 1: Maximal length. 3: Breadth at the middle of the diaphysis. 4: Depth of the diaphysis at the same level. 5: Proximal breadth. 6: Proximal depth. 10: Distal supra-articular breadth. 11: Distal articular breadth. 12: Depth of the sagittal crest. 13: Least depth of the medial condyle. 14: Greatest depth of the medial condyle; Figure S23. Simpson's diagrams of Dmanisi metatarsals from Layers IV-V, and Stratum A. 1: Maximal length. 3: Breadth at the middle of the diaphysis. 4: Depth of the diaphysis at the same level. 5: Proximal breadth. 6: Proximal depth. 10: Distal supra-articular breadth. 11: Distal articular breadth. 12: Depth of the sagittal crest. 13: Least depth of the medial condyle. 14: Greatest depth of the medial condyle; Table S1 Taxonomy Excel; Table S2 Typology E. hydruntinus; Table S3 Crania from Apollonia; Table S4 Typology Pseudhydruntines; Table S5 MC of pseudhydruntines; Table S6 Data and Scatter diagram of Dmanissi Strata A and B upper cheek teeth;  Table S7 CraLog Dmanissi; Table S8 Data and Scatter diagram of Dmanissi lower cheek teeth; Table S9 MC Dmanisi; Table S10 MT Dmanissi; Table S11 First phalanges Dmanisi Data