FIGURE 4. P3s of H. niobrarensis from Valentine Railway Quarries (arranged in order of increasing wear stage, from left to right). Scale bar equals 1 mm. Occlusal view above, anterior view below. 4.1, UNSM 122519. 4.2, UNSM 122523. 4.3, UNSM 122544. 4.4, UNSM 122500 (anterior view not available). 4.5, UNSM 122517.