**Appendix A**

#### **Figure A1.**

*Six-factor principal component analysis of fossil horse trackways plotted against modern horse trackways: step symmetry (SS); interior straddle/hoof width (IS/HW); stride length/height (SL/HT); ipsilateral step distance/ stride length (ISD/SL); diagonal step distance/stride length (DSD/SL); and diagonal/ipsilateral step distance (DSD/ISD). Trackways SC-1, OS-3, OS-4, OS-5, HSA-12, HSA-13, HSA-14, and WB-1 parameters indicative of galloping gaits; HSA-9, HSA-10, and HSA-11 parameters indicate of trotting gaits; trackways LAET-A, LAET-B, and LAET-C parameters indicative of racking gait (or running walk); and trackway DR-1 suggestive of walk.*



#### **Table A1.**

*Height/skeletal element ratios (multipliers) for fossil horses (after [7]).*

*New Studies on the Gaits Displayed by Miocene, Pliocene, and Pleistocene Fossil Horse… DOI: http://dx.doi.org/10.5772/intechopen.112157*


#### **Table A2.**

*Average linear stride ratios for various gaits (data from [25, 34]; original data, 2022).*


*morphometric parameters of modern Hippotigrine species (useful for estimating height of related fossil species).*

*Key*  *New Studies on the Gaits Displayed by Miocene, Pliocene, and Pleistocene Fossil Horse… DOI: http://dx.doi.org/10.5772/intechopen.112157*


*AM = American Museum of Natural History, New York, USA; NHMUK = British Museum of Natural History, London, UK; PH = Academy of Natural Sciences, Philadelphia, USA; SAM-EL = South African Museum, Cape Town, Republic of South Africa—Elandsfontein Section.*

#### **Table A4.**

*Height/skeletal element ratios (multipliers) for fossil zebras.*
