Crusafontina sp. 2

Zazhigin, Vladimir S. & Voyta, Leonid L., 2022, New Neogene anourosoricin shrews from northern Asia, Palaeontologia Electronica (a 29) 25 (3), pp. 1-36 : 17-18

Crusafontina sp. 2

Figure 6D

Material. Isolated left P4 (GIN 951/1003 (1040)) from the Selety 1A locality (Appendix 2: 6).

Description. The small P4 has a strongly undulated and sculptured crown outline between the parastyle and hypocone with a distinguished anterior notch, moderate protrusion of the protocone anteriorly and strong protrusion of the hypocone lingually; the parastyle forms a pointed anterior outline. The parastyle also modestly shifted anteriorly from the paracone base and is separated from it by a groove. The postcrista is relatively short, and tooth seems shortened in general. The hypocone is inflated and seems more massive than the protocone. The hypoconal flange is relatively long and moderately narrow with an angulated posterior outline; the posterior emargination is deep and shifted lingually. The short ectocingulum is present ( Figure 6D ).

Measurements. BL(P4) = 2.18; W(P4) = 2.06; LL(P4) = 1.76; PE(P4) = 1.41.

Remarks. The studied P4 from the Selety 1A locality is distinctly larger than that from C. exculta (BL = 1.97–2.08 mm, see van Dam, 2010: 750) and C. minima (BL = 1.84–1.96 mm, see Bown, 1980: 114) and smaller than that from C. kormosi (BL = 2.34–2.77 mm, see Mészáros, 1999a: 9) and especially C. vandeweerdi (BL mean = 2.72 mm, see van Dam, 2004: 750). This P4 is slightly larger than the P4 of C. endemica from European localities (BL = 1.97–2.16 mm, see van Dam, 2004: 750). Initially, we determined the tooth from Selety 1A as belonging to C. endemica because it quite precisely fits the crown features and outline of P4 of C. endemica from the Spanish Can Llobateres 1 locality ( van Dam, 2004: figure 2:16, but see point 3: 749). However, C. endemica is not known in the fossil record later than the end of the Vallesian. Therefore, either C. endemica survived in Asia to the beginning of the late Turolian, or we have a tooth of an unknown species of Crusafontina . On the other hand, based on the tooth size, outline shape and stratigraphic range, P4 from Selety 1A best matches the New World species C. magna (BL = 2.12–2.34 mm; W = 2.15–2.37 mm, see Bown, 1980). Morphologically, P4 from Selety 1A is similar to the tooth of C. magna in the distinct anterior projection of the parastyle (with the slight lingual shift from the paracone axis); in the well-developed long notch between the parastyle and protocone and shorter notch between the protocone and huge cone-like hypocone; and in the narrow and posteriorly protruded hypoconal flange with clear cingulum along the border and relatively deep posterior emargination. The poor quality of the Hutchinson and Bown images ( Bown, 1980: figure 3A) does not allow us to judge clear similarity in the small crown features. In summary, at present, we determined the tooth from Selety 1A as Crusafontina sp. 2 due to the absence of any tooth material for more detailed comparisons with type materials of C. magna . In addition, the similarity between P4 from Selety 1A and New World species does not contradict the data on the existence of the Beringian terrestrial bridge during the late Miocene ( Wen et al., 2016; Jiang et al., 2019), when C. magna could enter Asia from the New World (or vice versa), as Reumer (1999: 393) proposed for Blarinini members.

Stratigraphic and geographic range. At present, the distribution of this form includes only the Kazakh locality, Selety 1A, late Miocene Kedey Formation (Turolian, MN 12/13).

Figures

FIGURE 6. Teeth and bones of Paranourosorex seletiensis Storch and Zazhigin, 1996 (A, B), Crusafontina sp. 1, (C), Crusafontina sp. 2 (D) and Paranourosorex intermedius sp. nov. (E). A, GIN 951/1000 (holotype) from SLT/1A, left hemimandible fragment (cut image) with m1 and m2 in occlusal view (A2, magnified m2); B, GIN 951/1001 (paratype) from SLT/1A, left P4 in occlusal view; C, GIN 640/1004 from PVL/1A, left M1 in occlusal view; D, GIN 951/1003 SLT/ 1A, left P4 in occlusal view; E, GIN 948/1051 (holotype) from NST/1A, right dentary fragment with m1 and m2 (E1, occlusal view; E2, lateral view E3, medial view;). Scale bars equal 1 mm.