Table 4.
Summary of external, cranial, and mandibular measurements of 2 species of Ototylomys. For each species, specimens examined in this study are shown, including the holotype (MVZ 159512) of O. chiapensis. In addition, literature reports for O. phyllotis are included for comparison. Body mass is in grams; all other measurements are in millimeters. Where more than 1 specimen is reported, the mean value, if available, is followed by the range in parentheses. Cranial data from literature citations are rounded to the nearest 0.1 mm. Summary data from this study include adult specimens, and exclude measurements on broken or damaged body parts (Supplementary Data SD1), with sample size shown for each variable.
| Variable | Ototylomys phyllotis | Ototylomys chiapensis | ||
|---|---|---|---|---|
| Literature reports | This study | This study | Holotype | |
| Head and body length | (95–190)a (124–164)b |
152 (119–191) n = 40 |
172 (139–194) n = 18 |
187 |
| Total length | 309 (284–337)c (242–370)d |
296 (236–352) n = 30 |
319 (275–361) n = 11 |
361 |
| Tail | (100–190)a,e (109–174)b 156 (142–174)c (119–191)d |
143 (115–176) n = 30 |
153 (135–174) n = 11 |
174 |
| Hind foot | (23–30)b 27 (26–28)c (21–33)d (26–29)e |
28 (24–35) n = 40 |
32 (30–34) n = 18 |
32 |
| Ear | (21–26)b (24–25)e |
23 (18–28) n = 40 |
25 (20–27) n = 18 |
26 |
| Body mass | 63f (34–84)b (80–120)e |
72 (39–125.2) n = 16 |
103 (55–165) n = 16 |
110 |
| Condylobasal length | 36.7 (31.1–39.5) n = 34 |
38.7 (32.8–41.8) n = 19 |
41.5 | |
| Greatest length of skull | 40.5 (39.0–41.8)c,d | 38.6 (32.2–42.3) n = 39 |
41.5 (36.4–44.4) n = 17 |
43.8 |
| Breadth of braincase | 14.7 (13.2–16.1) n = 41 |
16.0 (15.2–16.8) n = 19 |
16.1 | |
| Least interorbital breadth | 6.2 (5.9–6.8)c | 6.0 (6 5–6.7) n = 41 |
7.1 (6.6–7.7) n = 19 |
7.2 |
| Mastoidal breadth | 14.8 (14.3–15.5)c | 14 (11.4–15.4) n = 41 |
14.7 (13.3–15.9) n = 19 |
15.6 |
| Breadth of rostrum | 6.2 (5.8–6.8)c | 5.3 (4.18–6.8) n = 41 |
6.0 (4.9–6.7) n = 19 |
6.5 |
| Length of nasal suture | 13.6 (9.6–15.6) n = 39 |
14.4 (12.2–16.4) n = 17 |
15.8 | |
| Zygomatic breadth | 19.5 (18.5–20.4)c,d | 18.8 (14.9–21.1) n = 41 |
19.6 (16.7–22) n = 19 |
20.6 |
| Length of incisive foramen | 7.5 (6.9–8.1)c,d | 6.9 (5.8–8.1) n = 41 |
6.9 (5.8–7.9) n = 19 |
7.5 |
| Height of braincase | 8.1 (6.9–8.9) n = 41 |
8.9 (8.4–9.4) n = 19 |
8.7 | |
| Coronal length of maxillary tooth row | 6.9 (6.4–7.3)c,d | 6.6 (5.6–7.6) n = 41 |
7.2 (7.0–7.4) n = 19 |
7.2 |
| Palatal length | 19.8 (16.8–21.6) n = 33 |
21.2 (17.7–22.8) n = 19 |
22.5 | |
| Postpalatal length | 14.1 (11.5–16.3) n = 40 |
14.6 (12.1–16.3) n = 19 |
16.0 | |
| Tympanic bullar length | 6.5 (5.2–8.8) n = 41 |
6.1 (5.2–6.8) n = 19 |
6.5 | |
| Tympanic bullar width | 4.8 (3.7–5.8) n = 41 |
5.1 (3.8–6.1) n = 19 |
4.8 | |
| Mandibular length | 19.5 (16.2–21.4) n = 41 |
20.4 (17.5–22.7) n = 19 |
22.2 | |
aNowak 1999; bReid 2009; cLawlor 1969; dHall 1981; eArita 2014; fHelm 1975.