Figure 2.

Morphological characteristics of pikas

A: PCA of morphological characteristics showing five well-distinguished subgenera. B: Heatmap of 20 morphological characteristics. Values of each morphological characteristic are scaled. Redder colors indicate larger values, bluer colors indicate smaller values. C–F: Box plots of morphological characteristics EPL (eyepit length), EPB (eyepit breadth), EL (ear length), and ABL (auditory bulla length) between (Alienauroa and Ochotona) and (Conothoa, Lagotona, and Pika) groups. Both O. dauurica and O. curzoniae are highlighted in bright blue. G–I: Reconstructed ancestral states of morphological characteristics, including head and body length (HBL), EPL, and ABL along phylogenetic lineages of extant pikas.