Osteology Of The Middle Eocene Ceratomorph Hyrachyus Modestus (Mammalia, Perissodactyla) Author Bai, Bin Author Meng, Jin Author Wang, Yuan-Qing Author Wang, Hai-Bing Author Holbrook, Luke text Bulletin of the American Museum of Natural History 2017 2017-06-09 2017 413 1 68 http://www.bioone.org/doi/10.1206/0003-0090-413.1.1 journal article 10.1206/0003-0090-413.1.1 0003-0090 4612938

TABLE 1 Measurements of skulls and lower jaws of Hyrachyus modestus and Hyrachyus eximius (mm) L = length; D = distance.

	Hyrachyus modestus (AMNH FM 12664)	Hyrachyus eximius (Qiu and Wang, 2007)
Skull
a Approximate measurements.
1. Basilar L	208.3	?
2. Premaxilla-condyle, L	211.0	340
3. Vertex L	228.5a	335
4. Occipital condyle-postorbital process, L	98.2	140
5. Premaxilla-postorbital process, L	128.3	200
6. P1-condyle, L	180.3	268
7. Postglenoid process-condyle, D	38.8	36
8. Nasal notch, L	21.1	46
9. Orbit-nasal notch, D	71.3	96
10. Width at condyles	38.6	?
11. Width at posttympanic process	56.6	?
12. Width at zygomatic arch	83.0a	177
13. Occiput height	60.5	66
14. Condyle, height×width	21.85×10.16	?
15. Paracondylar-posttympanic process, L	18.8	18
16. I1–M3, L	123.7	199.2
17. Diastema I1–P1	41.0	62.6
18. P1–M3, L	84.3	109.8
Ratio (%)
12:1	40	?
12:2	39.4	52.2
4:5	76.6	70
7:6	21.5	13.4
17:18	48.6	57
Mandibles
1. Total L	190.1	296
2. p1-angular process, L	150.9	240
3. p1-m3 L	83.9	111.4
4. Height at p2	30.4	37.1
5. Height at m1	36.1	44
6. Coronoid process, height	93.5	160
7. Condylar process, height	76.7	126
Ratio (%)
3:1	44.1	37.6
5:1	19.0	14.9
6:1	49.2	54
7:1	40.4	42.6
1. Maximum length	160.0	215
2. Maximum width	105.0	130
3. Width at distal end	35.1	?
4. Minimum width at neck	23.0	36
5. Glenoid cavity, length	28.3	35
Ratio (%)
2:1	65.6	60.5
4:3	65.4	?
5:4	123.1	97.2