Belongs within: Muridae.
Apodemus, the field mice, is a genus of small, soft-furred mice found in the temperate Palaearctic, where they are the most common small rodents in fields and broadleaf forests.
Apodemus (no Pliers)
Published 17 September 2007
The rodents are the most numerous of the traditional mammalian orders by a significant margin, making up about 40% of recent mammal species. Within that species diversity, over half belong to the Muroidea, the rats and mice. You thought a mouse was just a mouse and a rat was a slightly bigger mouse? Well, no. There are literally hundreds of species of mouse—about 1,300 to be more precise (if not necessarily accurate). And safe in the knowledge that the thought of so many rats is going to give some of you raving heebers, allow me to introduce the mouse genus Apodemus, the field mice.
Apodemus contains about twenty species distributed in broadleaf forests throughout the Palaearctic, and are the commonest rodents in said forests (Serizawa et al. 2000). Based on molecular clock studies, the genus has been estimated to have originated about eight million years ago, which is consistent with the presence of the fossil species Apodemus primaevus in Europe at the end of the Miocene (about seven million years ago—Michaux et al. 2002). Apodemus primaevus is believed to have been ancestral to the modern Balkan and Middle Eastern species A. mystacinus, a distinctive species that has been suggested to belong to its own genus, Karstomys. The majority of modern European Apodemus species were a later immigration, with their ancestor (A. dominans) arriving at the end of the Pliocene. Serizawa et al. (2000) also inferred that the various Asian species had split from each other earlier than the European species, and suggested that this may have reflected the different histories of broadleaf forest cover during the Pleistocene ice ages. Some broadleaf cover survived in Asia during the ice ages, allowing for the survival of wood mice over that time, while Europe became a broadleaf no-go zone.
Oh yes, and species of Apodemus possess supernumerary chromosomes, like the ones I mentioned for Leiopelma frogs. Interestingly, Zima et al. (2003) found that there was a relationship between number of B chromosomes and body size in male Apodemus flavicollis, suggesting that males with more B chromosomes had a selective advantage, probably in terms of their ability to survive winters. Some individuals may show variation in the number of B chromosomes in individual cells, but Kartavtseva (1999) found that such mosaic individuals dropped in abundance in autumn relative to individuals with constant chromosome numbers, suggesting that for some reason they were less hardy.
Systematics of Apodemus
<==Apodemus | i. s.: A. arianusIT07 | A. fulvipectusIT07 | A. hermonensisIT07 | A. jeanteti Michaux 1967P04 | A. miyakensis Imaizumi 1969I92 | A. wardiIT07 |--+--A. argenteusFS15 | `--+--A. speciosus Temminck 1845FS15, M76 | | |--A. s. speciosusMN91 | | `--A. s. ainuMN91 | `--+--+--A. agrarius (Pallas 1771)FS15, K92 | | `--A. chevrieriFS15 | `--+--A. peninsulae Thomas 1906FS15, K99 | | |--A. p. peninsulaeI92 | | `--A. p. giliacus (Thomas 1907)I92 | `--+--A. latronumFS15 | `--+--A. dracoFS15 | `--A. semotusFS15 `--+--A. gurkhaFS15 `--+--+--A. epimelasFS15 | `--A. mystacinusFS15 `--+--+--A. pallipesFS15 | `--A. uralensisFS15 `--+--A. witherbyiFS15 `--+--A. alpicolaFS15 `--+--+--A. hyrcanicusFS15 | `--A. sylvaticus (Linnaeus 1758)FS15, K92 | |--A. s. sylvaticusKK54 | |--A. s. dichrurus (Rafinesque-Schmaltz 1814)KK54 | |--A. s. islandicusBB-L86 | `--A. s. krkensisBP87 `--+--A. flavicollis (Melchior 1834)FS15, K92 `--+--A. ponticusFS15 `--A. rusigesFS15
*Type species of generic name indicated
[BB-L86] Bengtson, S.-A., G. Brinck-Lindroth, L. Lundqvist, A. Nilsson & S. Rundgren. 1986. Ectoparasites on small mammals in Iceland: origin and population characteristics of a species-poor insular community. Holarctic Ecology 9: 143–148.
[BP87] Burton, J. A., & B. Pearson. 1987. Collins Guide to the Rare Mammals of the World. Collins: London.
[FS15] Faurby, S., & J.-C. Svenning. 2015. A species-level phylogeny of all extant and late Quaternary extinct mammals using a novel heuristic-hierarchical Bayesian approach. Molecular Phylogenetics and Evolution 84: 14–26.
[IT07] Isaac, N. J. B., S. T. Turvey, B. Collen, C. Waterman & J. E. M. Baillie. 2007. Mammals on the EDGE: conservation priorities based on threat and phylogeny. PloS One 2 (3): e296.
[I92] Iwahashi, J. (ed.) 1992. Reddo Deeta Animaruzu: a pictorial of Japanese fauna facing extinction. JICC: Tokyo.
[K99] Kartavtseva, I. V. 1999. Seasonal observations on supernumerary chromosomes, mosaicism, and dynamics in two populations of the eastern-Asian wood mouse Apodemus peninsulae (Rodentia) from Primorskii Krai. Genetika 35 (7): 949–955 (transl. Russian Journal of Genetics 35 (7): 949–955).
[KK54] Klemmer, K., & H. E. Krampitz. 1954. Zur Kenntnis der Säugetierfauna Siziliens. Senckenbergiana Biologica 35 (3-4): 121–135.
[K92] Klompen, J. S. H. 1992. Phylogenetic relationships in the mite family Sarcoptidae (Acari: Astigmata). Miscellaneous Publications, Museum of Zoology, University of Michigan 180: i–vi, 1–154.
[M76] Masui, M. 1976. Nihon no Doobutsu. Kogakukan: Tokyo.
Michaux, J. R., P. Chevret, M.-G. Filippucci & M. Macholan. 2002. Phylogeny of the genus Apodemus with a special emphasis on the subgenus Sylvaemus using the nuclear IRBP gene and two mitochondrial markers: cytochrome b and 12S rRNA. Molecular Phylogenetics and Evolution 23 (2): 123–136.
[MN91] Miyamoto, K., M. Nakao, N. Sato & M. Mori. 1991. Isolation of Lyme borreliosis spirochaetes from tick vectors and feral rodents in Japan. In: Dusbábek, F., & V. Bukva (eds) Modern Acarology: Proceedings of the VIII International Congress of Acarology, held in České Budĕjovice, Czechoslovakia, 6–11 August 1990 vol. 1 pp. 125–132. SPB Academic Publishing: The Hague.
[P04] Popov, V. V. 2004. Pliocene small mammals (Mammalia, Lipotyphla, Chiroptera, Lagomorpha, Rodentia) from Muselievo (north Bulgaria). Geodiversitas 26 (3): 403–491.
Serizawa, K., H. Suzuki & K. Tsuchiya. 2000. A phylogenetic view on species radiation in Apodemus inferred from variation of nuclear and mitochondrial genes. Biochemical Genetics 38 (1–2): 27–40.
Zima, J., J. Piálek & M. Macholán. 2003. Possible heterotic effects of B chromosomes on body mass in a population of Apodemus flavicollis. Canadian Journal of Zoology 81 (8): 1312–1317.