Fig 1.
Terminology used for the mylagaulid molars.
(A), Upper molar; (B), Lower molar.
Fig 2.
Upper and lower teeth of Irtyshogaulus minor gen. et sp. nov.
(A), V 20328, left M1 (holotype); (B), V 20329.1, left M1; (C)-(E), V 20329.2–4, right M1s; (F), V 20329.5, left M2; (G)-(H), V 20329.6–7, right M2s; (I), V 20329.8, left M3; (J)-(L), V 20329.9–11, right M3s; (M)-(N), V 20329.12–13, right m1s; (O), V 20329.14, left m2; (P), V 20329.15, right m2; Scale bar, 1 mm.
Table 1.
Measurements for Irtyshogaulus minor gen. et sp. nov.
Fig 3.
Upper and lower teeth of Irtyshogaulus major gen. et sp. nov.
(A), V 20809, right M1 (holotype); (B)-(C), V 20810.1–2, left M3s; (D), V 20810.3, right M3; (E), V 20810.4, left p4 (broken); (F), V 20810.5, right m1; (G), V 20810.6, right m2; (H), V 20810.7, left m3; (I), V 20810.8, right m3; Scale bar, 1 mm.
Table 2.
Measurements for Irtyshogaulus major gen. et sp. nov.
Fig 4.
Phylogeny and distribution of mylagaulid and aplodontine rodents.
Strict consensus is from 58 most-parsimonious trees. Each tree has a Best Score of 1585, a Consistency Index of 0.1684 and a Retention Index of 0.6659. (A), Summarized phylogeny of Aplodontoidea, showing the phylogenetic positions of Mylagaulidae and Aplodontinae; (B), Phylogeny of Mylagaulidae and Aplodontinae. Branch lengths indicate the number of character changes, but have no temporal meaning. The paleobiogeographic distribution of mylagaulids and aplodontines was reconstructed by using parsimony criterion in Mesquite v3.03: black for North America, red for Asia, and blue for equal parsimony. Dashed square brackets on the right show the previously published classifications, and solid line brackets show the classification scheme used in this paper.