**5.1 Sample availability**

The *Scaphohippus sumani* footprints came from a quarry and had to be preserved in molds before they were destroyed. The molds and portions of the original trackway are housed at the San Bernardino County Museum, Redlands, California: location SBCM 1-130-394, holotype SBCM L1816-3436 (though at last report they are listed as missing; see photos in **Figure 10A–D** above, however, of the molds displaying the trackway). A few of the *Equus lambei* footprints are housed at the Royal Alberta Museum, Edmonton, Alberta: specimens DhPg-8 3840-3843, while several trackways have been resubmerged at St. Mary's Reservoir, Alberta, Canada. The *Eurygnathohippus hasumense* footprints are still located underground at Site G in Laetoli, Tanzania (a cast made of a portion of the trackway can be found in the Olduvai Gorge Museum, Tanzania). A few of the footprints of *Cremohipparion matthewi* found at the Hoya de la Sima site are housed at the Museo Municipal of Jumilla, Spain, but the bulk of the trackways are now protected by a structure at the trackway site. The trackways located at the Sierra del Colmenar site near Elche, Spain and the Colle di Osoppo site near Osoppo, Italy are still located in the field.
