Shaanxinus meifengensis, Lin & Lopardo & Haase & Uhl, 2019

Lin, Shou-Wang, Lopardo, Lara, Haase, Martin & Uhl, Gabriele, 2019, Taxonomic revision of the dwarf spider genus Shaanxinus Tanasevitch, 2006 (Araneae, Linyphiidae, Erigoninae), with new species from Taiwan and Vietnam, Organisms Diversity & Evolution (New York, N. Y.) 19 (2), pp. 211-276 : 268

Paraphyly of S. hehuanensis and its basal position on the mtDNA trees

The nesting of S. meifengensis sp. n. within S. hehuanensis sp. n. represents a plausible incidence of incomplete lineage sorting which resulted from rapid species radiation ( Funk and Omland 2003). The higher genetic variation in 16S and COI in S. hehuanensis sp. n. and its paraphyly with respect to S. meifengensis sp. n. may be a result of peripatric speciation. The high intraspecific genetic variation of S. hehuanensis sp. n. shown in trees in Figs. 41 , 42 , and 43 indicates a longer population history of this species compared to other congeners.

Since Taiwan was connected to the East Asian continent during the last glacial period, and the sea level rose and formed the Taiwan Strait about 13,000 to 11,000 years ago ( Voris 2000), many endemic animal and plant species represent descendants of relic species of the past fauna shared between continental East Asia and Taiwan. S. meifengensis sp. n. and S. hehuanensis sp. n. are genetically distant to other Taiwanese Shaanxinus species and occur at the highest altitudes among their congeners, which might indicate a retained ancestral state of adaptation to colder climate during glacial periods.

Figures

Fig. 41 Tree topology from the Bayesian analysis of the 16S dataset. Numbers below nodes indicate posterior probabilities. Nodes with posterior probability lower than 50% are collapsed. Lower left: Box plot showing p-distances for the 16S dataset between sequences of

Fig. 42 Tree topology from the Bayesian analysis of the COI dataset. Numbers below nodes indicate posterior probabilities. Nodes with posterior probability lower than 50% are collapsed. Lower left: Box plot showing p-distances for the COI dataset between sequences of