Article
Extended Data Fig. 6 | Skull size in HPG-15-3 compared to other birds. The
skull of HPG-15-3 is small compared to those of extant birds (total of n = 21 3
extant bird species sampled), here illustrated through a box plot of log 10 -
transformed postnasal skull length (as a proxy for the braincase), measured
from the craniofacial hinge to the caudal end of the cranium. Each box plot
illustrates the median (thick line) the 1st and 3rd quartiles (the hinges), and the
distance from the upper and lower hinge to the largest and smallest value no
further than 1.5× the interquartile range (the whiskers). HPG-15-3 is smaller than
swifts (n = 12), passerines (n = 23) and hummingbirds (n = 22)—and may even be
smaller than the smallest hummingbird, M. helenae.