Errata for Rankin et al. 2020, Palaeontologica Electronica
Rankin, Aime H., Emry, Robert J., and Asher, Robert J. 2020. Anatomical sciuromorphy in "protrogomorph" rodents. Palaeontologica
Electronica, 23(2):a25.

In Figure 4, the numbers for two landmarks (17 and 19) were mistakenly switched on the image of a skull of Arvicola amphibius (now corrected on our revised Fig. 4).

In Figures 9 and 10, we have corrected two mistakes. First, the wireframes on the outside of the axes were reversed; these are now correctly shown on our revised Figures 9 and 10. Second, the symbol for Dasyprocta was incorrectly shown as a triangle on Figures 9 and 10. This has been corrected to a star, reflecting this taxon's anatomical hystricomorphy (as indicated with a red arrow). This changes the boundaries of the masseter types slightly. It does not affect which masseter types overlap with the fossil specimens in PC3 vs PC4 (Figure 10), but does affect Ischyromys douglassi in PC1 vs PC2 (Figure 9). Previously, I. douglassi fell within the myomorphous, hystricomorphous and sciuromorphous boundaries, but now, it overlaps with just the latter two, requiring a sentence in the Results section to be changed to the following: "Ischyromys douglassi (USNM 617532) is centrally placed and nested within the overlap between the hystricomorphous and sciuromorphous species" (p. 17, line 3). In the Discussion section, one sentence should be changed to the following: "When considering the first two principal components in our study (Figure 9), Ischyromys douglassi overlaps with the sciuromorphous and hystricomorphous clusters, but not the protrogomorphous cluster (as defined by extant rodents only)" (p. 21, line 13).

revised Fig. 4
revised Fig. 9
revised Fig. 10

Our overall conclusion regarding the morphometric analysis, as stated in our abstract, remains unchanged:
"A geometric morphometric analysis of cranial landmarks suggests that I. typus resembles extant, anatomically protrogomorphous rodents, whereas USNM 617532 falls within the range of non-protrogomorphous rodents."