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In this study, five blind mole rat specimens of the Nannospalax sp. were collected from two different localities in Muş Province, Eastern Anatolia, Türkiye. Cytogenetic analyses of these specimens revealed that the diploid chromosome number, the fundamental chromosome number, and the number of autosomal arms were 2n = 52, NF = 84 and NFa = 80, respectively. The X chromosome was medium-sized and submetacentric, while the Y chromosome was small and acrocentric. Active nucleolus organizer regions (NORs) were observed on the telomeric regions of three bi-armed autosomal pairs in all examined specimens. This study presents new karyological data regarding the blind mole rat with 2n = 52 chromosomes distributed in the Eastern Anatolia region from Türkiye.

Subterranean rodents spend most of their lives in underground burrow systems, and most studies to date on their morphological, behavioral, and physiological, adaptations have been based on their whole-life existence in subterranean ecotopes. However, a few studies have reported that some subterranean rodents exhibit aboveground activity under particular circumstances, and the results of these studies help zoologists to better understand the adaptations of subterranean rodents coping both with belowground and aboveground environments. These studies, however, do not include direct observations of the aboveground activity of these rodents. Moreover, studies into the factors that influence the movement of these subterranean rodents outside of their burrow systems are relatively scarce. Here, we report the aboveground activity pattern of plateau zokor (Myospalax fontanieri) based on videos and photographs captured by infrared cameras combined with radiotracking technology in the eastern Qilian Mountains, northwest China. In addition, the potential factors that influence the aboveground activity of plateau zokor, including temperature, humidity, food, dispersal, and mating, were studied in 2015 and 2016. We found that, of the 16 zokors with radiocollars, five females moved aboveground during the day and night in June and July 2015, with the frequency of their aboveground activity being higher during the day than that at night. Temperature, humidity, mating, and dispersal, had no effects on aboveground plateau zokor movement. However, results of a binary logistic regression indicated that the crude fat contents of aboveground and belowground plants were positively and negatively correlated with the aboveground activity of these zokors, respectively. We infer that plateau zokor move on the ground to forage for plants with higher fat content and that changes in available nutrients might serve as potential cues that affect the surface activity of plateau zokor.

Zokors (Myospalacinae) continue to be the center of systematics discussions. Phylogenetic schemes based on molecular data do not always agree with each other, nor can phylogenetic schemes based on paleontological material be complete due to the only-partial description of West Siberian zokors. This paper tries to fill this gap and presents a description of the West Siberian lineage from the late early Pleistocene to the present, together with an analysis of molar development in other zokor lineages. We describe two new species and one subspecies (Myospalax myospalax krukoveri n. ssp., Myospalax convexus n. sp., Prosiphneus razdoleanensis n. sp.) ancestral to the extant Myospalax myospalax Laxmann, 1769. We also reveal differences in the ontogeny of molars of modern species that were not previously detailed. These differences, together with paleontological data, indicate that in the West Siberian lineage, peramorphosis occurred in the structure of the chewing surface (with the exception of the lower m1), whereas in all other zokor lineages, there was pedomorphosis. On the basis of these results, we suggest a new view on the systematics of Myospalacinae. UUID: http://zoobank.org/b06d6c99-1648-454b-9b95-4d869bfe8bdc

It is supposed that the subterranean lifestyle in mammals is reflected in ear morphology and tuning of hearing to low frequencies. We studied two root-rat species to see if their ear morphology reflects the difference in the amount of their surface activity. Whereas the more subterranean Tachyoryctes splendens possesses shorter pinnae as expected, it has smaller bullae compared to the more epigeic Tachyoryctes macrocephalus. The ratio between the eardrum and the stapedial footplate area and the ratio between the mallear and the incudal lever were lower in T. splendens (19.3 ± 0.3 and 1.9 ± 0.0, respectively) than in T. macrocephalus (21.8 ± 0.6 and 2.1 ± 0.1), probably reflecting the latter’s higher surface activity. The cochlea in both species has 3.5 coils, yet the basilar membrane is longer in the smaller T. splendens (13.0 ± 0.5 versus 11.4 ± 0.7 mm), which indicates its wider hearing range and/or higher sensitivity (to some frequencies). In both root-rat species, the highest density of outer hair cells (OHC) was in the apical part of the cochlea, while the highest density of inner hair cells (IHC) was in its middle part. This OHC density pattern corresponds with good low-frequency hearing, whereas the IHC pattern suggests sensitivity to higher frequencies.

In this study, we aimed to develop a species-level phylogeny for the Nannospalax genus, identify cryptic species that are difficult to differentiate using standard methods, and further evaluate the relationships across chromosomal forms of several species. 16S rRNA gene sequences from 81 Turkish regions were evaluated and statistical analyzes were conducted. Results are as follows; (i) Nannospalax cilicicus was found to be monophyletic and sister in relation to Nannospalax xanthodon ; (ii) We suggested for the first time that the Central-Anatolian populations should be classified under the species name Nannospalax cilicicus (stat. n.); (iii) the unidentified 2 n  = 52 cytotypes from Bolu and Nannospalax leucodon cytotypes were reciprocally monophyletic, these data support the notion that the 2 n = 52 cytotypes from Bolu belong to an unidentified taxon; (iv) study also offered evidence for the monophyly of N. tuncelicus for the first time; (v) Nannospalax xanthodon (2 n = 36, 38, and 40) and Nannospalax nehringi composed several species-specific clades, which form polytomy structure, so relationships between these species are still unclear.

Probasin protein was originally identified as a basic protein present in rat prostate epithelium. So far, its physiological role, its origin, and its presence in other species including humans remain largely elusive. With the ever-growing number of genome assemblies, thus far, probasin genes (Pbsn/PBSN) have only been predicted in a subset of rodent genomes. In this study, we addressed the phylogeny of probasin genes and found them to be exclusively present in members of the superfamily Muroidea. It first emerged in the so-called pseudoautosomal region, a subtelomeric gene cluster of both mammalian sex chromosomes. During evolution of the Muroidea lineages, probasin recombined to the X-specific region of the X-chromosome in mice and hamster species. This event likely saved the gene from events that other pseudoautosomal genes suffered, namely displaying an increase in G and C nucleotide composition or accumulation of repetitive elements. We observed changes to its coding region, e.g., sequence insertions in exon 6, which challenge the current understanding of rodent phylogeny, in particular regarding the evolutionary history of tribe formation within the subfamily Murinae. Analyzing the evolution of probasin genes in Muroidea allows fostering understanding of phylogenetic relationships in one of the largest groups of mammalian species.

Burrowing mammals are important ecosystem engineers, especially in open ecosystems where they create patches that differ from the surrounding matrix in their structure or ecosystem functions. We evaluated the fine-scale effects of a subterranean ecosystem engineer, the Lesser blind mole rat on the vegetation composition of sandy dry grasslands in Hungary. In this model system we tested whether the characteristics of the patch (mound size) and the matrix (total vegetation cover in the undisturbed grassland) influence the structural and functional contrasts between the mounds and the undisturbed grasslands. We sampled the vegetation of 80 mounds and 80 undisturbed grassland plots in four sites, where we recorded the total vegetation cover, and the occurrence and cover of each vascular plant species. We used two proxies to characterise the patches (mounds) and the matrix (undisturbed grassland): we measured the perimeter of the mounds and estimated the total vegetation cover of the undisturbed grasslands. First, we compared the vegetation characteristics of the mounds and the surrounding grasslands with general linear models. Second, we characterised the contrasts between the mounds and the undisturbed grassland by relative response indices (RRIs) of the vegetation characteristics studied in the first step. Species composition of the vegetation of the mounds and undisturbed grasslands was well separated in three out of the four study sites. Mounds were characterised by lower vegetation cover, lower cover of perennial graminoids, and higher diversity, and evenness compared to undisturbed grasslands. The contrast in vegetation cover between mounds and undisturbed grasslands increased with decreasing patch size. Increasing vegetation cover in the matrix grasslands increased the contrasts between the mounds and undisturbed grasslands in terms of total cover, perennial graminoid cover, diversity, and evenness. Our results suggest that mole rat mounds provide improved establishment conditions for subordinate species, because they are larger than other types of natural gaps and are characterised by less intense belowground competition. The ecosystem engineering effect, ., the contrast between the patches and the matrix was the largest in the more closed grasslands.

Published studies and ten new unpublished records included herein reveal that approximately 174 species of endoparasites (helminths and protozoans) are known from 65 of 163 species of rodents that occupy the subterranean ecotope globally. Of those, 94 endoparasite species were originally described from these rodents. A total of 282 host-parasite associations are summarized from four major zoogeographic regions including Ethiopian, Palearctic/Oriental, Nearctic, and Neotropical. Thirty-four parasite records from the literature have been identified to only the level of the genus. In this summary, ten new records have been added, and the most current taxonomic status of each parasite species is noted. Interestingly, there are no data on endoparasites from more than 68% of described subterranean rodents, which indicates that discovery and documentation are at an early stage and must continue.

Rodents show a wide range of anatomical, physiological, and behavioral adaptations to life underground. Cranial and postcranial bone morphologies are deeply impacted by the modes of digging, which can involve either incisors or claws. However, the morphological variation of these elements still needs to be accurately quantified to assess the degree of specializations of the fossorial rodent families in regards to their respective evolution. Here, we focus on the morpho-functional characteristics of the masticatory apparatus in two families of subterranean rodents, the Spalacidae and Bathyergidae. We quantify skull shape in five spalacid genera using geometric morphometric methods, as well as biomechanical estimates for adductor muscles, which are compared with data previously published on bathyergids. We show that skull shape of spalacids has a greater disparity and lower biomechanical estimates than bathyergids, in which the fossorial activity, notably chisel-tooth digging, more significantly impacted the evolution of the skull. Among spalacids, Spalax shows the most extreme specializations to life underground and displays the highest number of morphological convergences with chisel-tooth digging bathyergids, especially regarding its cranial shape and high biomechanical estimate for the temporalis muscle. Fewer morphological convergences were observed between other spalacids and bathyergids. Different evolutionary histories can potentially explain discrepancies observed between the two families, the first bathyergid morphological adaptations to fossorial life being much older than those of spalacids.

This paper reports the fossil zokors (Myospalacinae) collected from the lower Pliocene (~4.4 Ma) of Zanda Basin, southwestern Tibet, which is the first record in the hinterland of Tibetan Plateau within the Himalayan Range. Materials include 29 isolated molars belonging to Prosiphneus eriksoni (Schlosser, 1924) by having characters including large size, highly fused roots, upper molars of orthomegodont type, m1 anterior cap small and centrally located, and first pair of m1 reentrants on opposing sides, high crowns, and high value of dentine tract parameters. Based on the cladistics analysis, all seven species of Prosiphneus and P. eriksoni of Zanda form a monophyletic clade. P. eriksoni from Zanda, on the other hand, is nearly the terminal taxon of this clade. The appearance of P. eriksoni in Zanda represents a significant dispersal in the early Pliocene from its center of origin in north China and Mongolian Plateau, possibly via the Hol Xil-Qiangtang hinterland in northern Tibet. The fast evolving zokors are highly adapted to open terrains at a time when regional climates had become increasingly drier in the desert zones north of Tibetan Plateau during the late Miocene to Pliocene. The occurrence of this zokor in Tibet thus suggests a rather open steppe environment. Based on fossils of large mammals, we have formulated an \"out of Tibet\" hypothesis that suggests earlier and more primitive large mammals from the Pliocene of Tibet giving rise to the Ice Age megafauna. However, fossil records for large mammals are still too poor to evaluate whether they have evolved from lineages endemic to the Tibetan Plateau or were immigrants from outside. The superior record of small mammals is in a better position to address this question. With relatively dense age intervals and numerous localities in much of northern Asia, fossil zokors provide the first example of an \"into Tibet\" scenario--earlier and more primitive taxa originated from outside of the Tibetan Plateau and the later the lineage became extinct in southwestern Tibet.