Nectogalini, ANDERSON, 1879

Pažitková, Barbora & Horáček, Ivan, 2024, Shrews Of Tribe Nectogalini (Mammalia, Eulipotyphla, Soricidae) In The Fossil Record Of The Czech Republic And Slovakia, Fossil Imprint 80 (2), pp. 190-228 : 206

Mid-European Nectogalini vs. Asiatic clades

Pl. 7

In addition to the above performed comparisons, we analysed the phenotype relations between the studied mid-European taxa and a set of items representing the extant Oriental clades, namely Soriculus nigrescens , Episoriculus macrurus , E. leucops , Chimarrogale platycephalus (TEMMINCK, 1842) , and Anourosorex sp. ( Anourosoricini ANDERSON, 1879 , formerly part of Neomyini MATSCHIE, 1909 ).

In contrast to the latter two genera, which exhibit distinct differences, the representatives of Soriculus and Episoriculus reveal obvious similarities in cranial and dental characters to the European Pliocene gibberodon , for which that species was included in these extant genera (e.g., Ellermann and Morrison-Scott 1951, Repenning 1967), until Hutterer (1994) demonstrated the differences validating the concept of an independent genus Asoriculus , proposed by Kretzoi (1962).

We examined the samples of these extant species using the biometric technique applied in other OTUs, and quantified the differences in form of Euclidean distances of 42 metric variables represented in the majority of the OTUs (unfortunately except for OTU V), normalized by filtering off their size differences, and further evaluated by PCA and cluster analyses.

The comparison of frequency distributions for basic dental dimensions in particular OTUs is summarized in Text-fig. 9. The results of multivariate analyses demonstrating similarity relations among particular OTUs are visualized in Text-figs. 10 and 11. They show close relations among the W-Palearctic clades (Asoriculus-Neomys) and distinct differences from both Episoriculus and Soriculus samples. The results thus strongly support the stand of Kretzoi (1962) and Hutterer (1994) against alternative synonymisation of Asoriculus , Soriculus and Episoriculus (e.g., Ellermann and Morrison-Scott 1951, Repenning 1967). The case of Macroneomys brachygnathus (Q 2/Q 3 border, 11 European sites) occupying the most distant position will be discussed elsewhere.

European radiation is characterized by successive enlarging of body size and arrangements of horizontal ramus (including strengthening of the distal position of coronoid process) in the sequence AsorQ1-NeomQ2, later followed by divergence to the morphotypes of Neomys milleri and Neomys fodiens during the Middle Pleistocene. Episoriculus macrurus BLANDFORD, 1888 is smaller in comparison with the extant European species, and there is occasional overlap with Neomys milleri . Its size is comparable to Asoriculus or Q 2 Neomys , while Episoriculus leucops HORSFIELD, 1855 is approximately of Neomys fodiens size (or exceeding it in some dimensions – e.g., pL, Cd1Cd2). Therefore, it exceeds all the fossil forms in terms of size, similarly to Soriculus nigrescens . Overall, even though we witnessed some overlap in particular measurements (esp. E. macrurus with Asoriculus ), they differ considerably in combinations of characters.

We noticed several characteristics that are shared by all examined Asian species: (i) the upper sigmoid notch is shallow and round, (ii) the coronoid process is robust, especially in Soriculus but with the exception of E. macrurus , (iii) the entoconid is long (especially in Soriculus ), but in Episoriculus it is not very significant, (iv) there are only three unicuspid teeth in the rostral part of the upper dentition (however, Soriculus carries a tiny residual Z4 on the palatal edge of the P, (v) the first two upper molars possess a peculiarly shaped hypocone with strengthened cingulum, which is notably distanced from protocone. Even though we do not have access to the upper dentition of Asoriculus , according to Reumer (1984), this is a trait clearly distinguishing Asoriculus from Episoriculus and Soriculus .