Table 4. Summary statistics for each trait of compared species in clade 4.

Trait	Levene’s test		Regression model
	Statistic	assignment	Type	F-test/Chi-square test
Adjusted mensural traits were tested for normality and did not require transformation. Subsequently, data were subjected to Levene’s equality of variance tests and assigned to linear modeling (equal variances) or generalized least squares modeling (unequal variances). Meristic traits were under-dispersed and assessed using glm models with quasi-Poisson error distributions. Variance test probabilities of linear models (F-tests) and generalized linear models (Chi-square tests) are provided. See Methods for abbreviations. –: Not available. NS: Not significant.
Mensural traits
TrunkL	0.012	Unequal	gls	0.016
ED	0.162	Equal	lm	<0.001
HL	<0.001	Unequal	gls	<0.001
HW	0.002	Unequal	gls	<0.001
NarEye	0.073	Equal	lm	<0.073
SnEye	0.049	Unequal	gls	<0.001
SnW	0.226	Equal	lm	<0.001
Meristic traits
DS	–	–	glm	<0.001
VS	–	–	glm	<0.001
CN	–	–	glm	0.056
IS	–	–	glm	NS
SL	–	–	glm	<0.001
IL	–	–	glm	<0.001
SL1T	–	–	glm	<0.001
SL1F	–	–	glm	<0.001
CloacS	–	–	glm	NS
Chin	–	–	glm	<0.001