Figure 1
From: An early Oligocene fossil demonstrates treeshrews are slowly evolving “living fossils”
Upper and lower dentition (in color) of Ptilocercus kylin sp. nov., compared with P. lowii (USNM 32409, in gray-scale).
(A) Crown view of the upper dentition. Fossils include the lingual half of a left M1 (IVPP V20689, reversed), the buccal half of a right M1 (IVPP V20690), a complete right M2 (IVPP V20691) and the buccal half of a left M3 (IVPP V20692, reversed). I1-2, C, P2-4 and M1-3 are shown for P. lowii. (B) Crown view of the lower dentition. Fossils include an isolated right lower canine (IVPP V20693), a right jaw fragment preserving p3-4 and the alveoli for i2-3, c and p2 (IVPP V20694), an isolated right m1 (IVPP V20695) and a right jaw fragment preserving m2-3 (IVPP V20696, holotype). The alignment of the fossils is based on a left lower jaw fragment retaining a small portion of the i2-3 alveoli, alveoli and roots of c and p2 and p3-m3 (IVPP V20699, Fig. 2 and Supplementary Information). The i1-3, c, p2-4 and m1-3 are shown for P. lowii. (C), Lingual view of the lower dentition of P. kylin. (D), Buccal view of the dentition of P. kylin. Scale bar equals 5 mm.
