The morphological measurements will be performed only at Dutch participants at the VU University medical center.
Morphological measurements of this skull exceed the corresponding parameters not only for other ancient and modern bear skulls from Yakutia, but also the maximal sizes of the largest representatives of modern brown bear subspecies from Eurasia (U. a. beringianus, Amur River region, Russian Far East and U. a. piscator, Kamtchatka Peninsula 54 (Supplementary Table 1).
Although in most comparisons tarsus, gape length, gape width, and gape area were greater for non-evictor than evictor chicks (Fig. 2b e, Table 1), in contrast to mass data, these morphological measurements were highly variable between treatment groups, so that only two of the differences reached statistical significance (Table 1).
Prior to applying phylogenetic comparative methods, the phylogeny was preemptively pruned to include only the 49 taxa for which morphological measurements could be collected, as to not inadvertently influence (with missing data) the outcome of the analyses.
External morphological measurements were taken from all 48 individuals, while internal measurements were only available for the 31 morphotypes.
Only in the case of quantitative and continuous characters such as morphological measurements need they be replaced by other appropriate character transformations.
This type of analysis is only possible with a data set such as ours where correlation of multiple morphological measurements can be made without relying on classifications based on kinetoplast and nucleus number.
The newest models also provide morphological measurements for certain species, although limited to sperm head morphology.
Morphological measurements of museum specimens suggest that the three subspecies differ significantly in body size.
Our research primarily focuses on studying the extensive nest diversity exhibited by the family, by taking morphological measurements directly from nest specimens in museum collections.
