A New Montane Species of Spiny Pocket Mouse (Rodentia: Heteromyidae: Heteromys) from Northwestern Costa Rica Author Anderson, Robert P. Author Timm, Robert M. text American Museum Novitates 2006 2006-03-16 3509 1 1 39 http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1206%2F0003-0082(2006)3509%5B1%3AANMSOS%5D2.0.CO%3B2 journal article 3674 10.1206/0003-0082(2006)3509[1:ANMSOS]2.0.CO;2 2f8c7065-6e4b-46b1-89af-809f51afdcf2 0003-0082 4735318

TABLE 1 Descriptive Statistics and Results of t -Tests Comparing Adults in Age Class 4 of Heteromys desmarestianus and H. nubicolens in Northwestern Costa Rica for External Measurements, Mass, Cranial Measurements, and Three Derived Ratios a

	H. desmarestianus	H. nubicolens
a Mean ± standard error, sample size, and observed range (minimum–maximum) are given for each species. Measurements with significant differences in two-tailed t -tests comparing means of the species are indicated (* 5 P # 0.05; ** 5 P # 0.01; *** 5 P # 0.001; **** 5 P # 0.0001; n.s. 5 P. 0.05). Note that whereas averages of most measurements are larger for H. nubicolens, averages for least interorbital constriction, interparietal length, and parietal breadth are larger in H. desmarestianus. Units are millimeters unless otherwise noted.
Total length****	292.2 ± 3.9, 46 (238–353)	322.2 ± 2.7, 41 (291–358)
Head-and-body length**	138.7 ± 1.9, 52 (96–169)	146.4 ± 1.5, 52 (104–183)
Tail length****	152.8 ± 2.6, 46 (128–210)	174.8 ± 1.7, 41 (150–197)
Tail/head-and-body ratio, × 100 (%; ***)	110.0 ± 1.8, 46 (90.8–146.9)	119.3 ± 1.9, 41 (95.6–179.8)
Hind foot length****	35.8 ± 0.3, 52 (32–40)	38.7 ± 0.2, 51 (35–42)
Ear length (n.s.)	17.9 ± 0.2, 51 (13–20)	17.8 ± 0.2, 51 (15–21)
Mass (grams)**	75.4 ± 2.7, 42 (37–110)	86.6 ± 2.4, 50 (60–136)
Occipitonasal length****	36.506 ± 0.109, 176 (32.71–40.09)	38.630 ± 0.177, 51 (35.72–41.02)
Zygomatic breadth****	16.519 ± 0.054, 134 (15.20–18.52)	17.533 ± 0.085, 42 (16.40–18.51)
Rostral length****	16.558 ± 0.062, 176 (14.51–18.67)	17.950 ± 0.110, 50 (15.82–19.36)
Nasal length****	15.283 ± 0.065, 175 (13.05–17.25)	16.079 ± 0.112, 51 (13.89–17.78)
Least interorbital constriction****	9.789 ± 0.036, 176 (8.39–11.11)	9.250 ± 0.067, 51 (8.20–10.40)
Squamosal breadth****	15.471 ± 0.032, 176 (14.40–16.59)	15.932 ± 0.059, 51 (15.19–17.74)
Maxillary toothrow length****	5.252 ± 0.017, 176 (4.63–5.99)	5.461 ± 0.035, 51 (4.97–5.92)
Interparietal width****	9.289 ± 0.042, 176 (8.02–10.75)	9.715 ± 0.066, 51 (8.24–10.84)
Interparietal length****	5.288 ± 0.033, 176 (4.23–6.49)	4.912 ± 0.071, 51 (3.82–6.11)
Parietal breadth****	14.286 ± 0.033, 176 (13.11–15.50)	13.795 ± 0.045, 51 (12.85–14.60)
Skull depth****	11.202 ± 0.023, 176 (10.43–11.99)	11.640 ± 0.032, 51 (11.00–12.09)
Least interorbital constriction/ occipitonasal length ratio, × 100 (%; ****) Parietal breadth/ occipitonasal length ratio, × 100 (%; ****)	26.824 ± 0.076, 176 (23.93–28.79) 39.164 ± 0.093, 176 (35.38–41.80)	23.944 ± 0.133, 51 (22.20–26.46) 35.742 ± 0.175, 51 (32.63–38.94)