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Rhagamys Temporal range: Pleistocene–Holocene PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Family:	Muridae
Tribe:	Apodemini
Genus:	†Rhagamys Major, 1905
Species:	†R. orthodon
Binomial name
†Rhagamys orthodon Hensel, 1856

Rhagamys is an extinct genus of rodents in the subfamily Murinae, the Old World mice and rats. The genus was established by the Swiss zoologist Charles Immanuel Forsyth Major to accommodate Rhagamys orthodon, which is the only species in the genus. It was endemic to the Mediterranean islands of Corsica and Sardinia, descending from Rhagapodemus, which had colonised the islands around 3.6 million years ago. Its closest living relatives are of the genus Apodemus, which includes the field and wood mice.

Taxonomy and evolution

The ancestors of Rhagamys, belonging the widespread genus Rhagapodemus, first arrived in Corsica-Sardinia during the Early-Late Pliocene transition, around 3.6 million years ago. Three chronospecies of the lineage have been named, including "Rhagapodemus" azzarolii from the earliest Late Pliocene, followed by "Rhagapodemus" minor from the Early Pleistocene, succeeded by Rhagamys orthodon, which ranged from the Middle Pleistocene to Holocene. The molars of Rhagamys are similar to those of the wood mouse (Apodemus sylvaticus) and the striped field mouse (Apodemus agrarius) but are larger and more derived, being hypsodont teeth suitable for feeding on a coarse, abrasive diet. Over time, The Rhagapodemus-Rhagamys lineage increased in size, with Rhagamys orthodon having an estimated mass of approximately 90 grams (3.2 oz), two and a half times larger than its mainland ancestor, an example of island gigantism.

Paleoenvironment and extinction

Before the arrival of humans on the islands in about 8000 BC, Corsica and Sardinia had their own highly endemic depauperate terrestrial mammal fauna which besides Rhagamys orthodon included a species of dwarf mammoth (Mammuthus lamarmorai), the Tyrrhenian vole (Microtus henseli), the Sardinian pika (Prolagus sardus), the shrew Asoriculus similis, a mole (Talpa tyrrhenica), the Sardinian dhole (Cynotherium sardous), a galictine mustelid (Enhydrictis galictoides), three species of otter (Algarolutra majori, Sardolutra ichnusae, Megalenhydris barbaricina) and a deer (Praemegaceros cazioti). The small mammals, including Rhagamys, persisted for many thousands of years after the first human arrival on the islands, with the youngest radiocarbon date for Rhagamys on Sardinia being around 822-776 BC, while on Corsica the youngest dates for the species are around 393 BC. It was almost certainly extinct by the 6th century AD. The cause of the extinction is unknown, but may be due to invasive species introduced by new arrivals to the islands such as Carthaginians and the Romans.

The only endemic mammal still found on the islands is the Sardinian long-eared bat (Plecotus sardus).

References

1. Piras, Paolo; Sansalone, Gabriele; Marcolini, Federica; Tuveri, Caterinella; Arca, Marisa; Kotsakis, Tassos (2012-11-30). "Evolutionary Trends and Stasis in Molar Morphology of Rhagapodemus-Rhagamys Lineage in the Pleistocene of Sardinia". Rivista italiana di Paleontologia e Stratigrafia. 118 (3). doi:10.13130/2039-4942/6018.
2. Musser, G. G.; Carleton, M. D. (2005). "Superfamily Muroidea". In Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 1496–1497. ISBN 978-0-8018-8221-0. OCLC 62265494.
3. Alexandra van der Geer; George Lyras; John de Vos; Michael Dermitzakis (2011). Evolution of Island Mammals: Adaptation and Extinction of Placental Mammals on Islands. John Wiley & Sons. p. 124. ISBN 978-1-4443-9128-2.
4. van den Hoek Ostende, Lars W.; van der Geer, Alexandra A.E.; Wijngaarden, Carlijne L. (July 2017). "Why are there no giants at the dwarves feet? Insular micromammals in the eastern Mediterranean". Quaternary International. 445: 269–278. doi:10.1016/j.quaint.2016.05.007.
5. Lomolino, Mark V.; van der Geer, Alexandra A.; Lyras, George A.; Palombo, Maria Rita; Sax, Dov F.; Rozzi, Roberto (August 2013). Triantis, Kostas (ed.). "Of mice and mammoths: generality and antiquity of the island rule". Journal of Biogeography. 40 (8): 1427–1439. doi:10.1111/jbi.12096. ISSN 0305-0270.
6. Palombo, Maria Rita; Rozzi, Roberto (April 2014). "How correct is any chronological ordering of the Quaternary Sardinian mammalian assemblages?". Quaternary International. 328–329: 136–155. doi:10.1016/j.quaint.2013.09.046.
7. Valenzuela, Alejandro; Torres-Roig, Enric; Zoboli, Daniel; Pillola, Gian Luigi; Alcover, Josep Antoni (2021-11-29). "Asynchronous ecological upheavals on the Western Mediterranean islands: New insights on the extinction of their autochthonous small mammals". The Holocene. 32 (3): 137–146. doi:10.1177/09596836211060491. ISSN 0959-6836. S2CID 244763779.
8. Mucceda, M.; Kiefer, A.; Pidincedda, E.; Veith, M. (2002). "A new species of long-eared bat (Chiroptera, Vespertilionidae) from Sardinia (Italy)" (PDF). Acta Chiropterologica. 4 (2): 121–135. doi:10.3161/001.004.0202.
9. Amori,Giovanni; Gippoliti, Spartaco; Luiselli, Luca (2013). "A short review of the roles of climate and man in mammal extinctions during the Anthropocene". Anthropocene—Natural and Man-made Alterations of the Earth's Fragile Equilibrium. 25: 95–99. doi:10.1007/s12210-013-0240-6. S2CID 84651348.

v t e Myomorpha
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Rodentia
Myomorpha †Anomalomyidae Anomalomys Anomalospalax Prospalax Dipodoidea †Aksyiromys †Banyuesminthus †Elmymys †Primisminthus †Simiacritomys Dipodidae Allactaginae Allactaga Allactodipus Pygeretmus Scarturus Cardiocraniinae Cardiocranius Salpingotulus Salpingotus Dipodinae Dipodini Dipus Eremodipus Jaculus Stylodipus Paradipodini Paradipus Euchoreutinae Euchoreutes †Simimyidae Nonomys Simimys Sminthidae †Allosminthus †Gobiosminthus †Heosminthus †Heterosminthus †Lophocricetus †Macrognathomys †Megasminthus †Miosicista †Paraminthus †Schaubemys †Shamosminthus Sicista †Sinosminthus †Tyrannomys Zapodidae Eozapus †Javazapus Napaeozapus †Pliozapus †Sinozapus †Sminthozapus Zapus Muroidea †Armintomyidae Armintomys Platacanthomyidae †Neocometes Platacanthomys Typhlomys Spalacidae Myospalacinae Eospalax Myospalax †Pliosiphneus Rhizomyinae †Brachyrhizomys Cannomys Rhizomys Tachyoryctes Spalacinae Nannospalax Spalax Eumuroida See below↓
Eumuroida Calomyscidae Calomyscus Cricetidae †Copemys †Eumys †Wilsoneumys Arvicolinae Arvicolini Arvicola †Mimomys Clethrionomyini †Allophaiomys †Altaiomys Alticola †Borsodia Caryomys Clethrionomys Craseomys Eothenomys †Pitymimomys †Prolagurus Dicrostonychini Dicrostonyx †Predicrostonyx Ellobiusini Bramus Ellobius Lagurini Eolagurus Lagurus Lemmini Lemmus Myopus †Plioctomys Synaptomys †Tobienia Microtini Alexandromys Chionomys Hyperacrius Lasiopodomys Lemmiscus Microtus Mictomicrotus Neodon Proedromys Stenocranius Volemys Ondatrini †Cosomys Neofiber †Ogmodontomys Ondatra Pliophenacomyini Arborimus Phenacomys Pliomyini Dinaromys †Pliomys Cricetinae Allocricetulus †Apocricetus Cansumys †Collimys †Cricetinus †Cricetulodon Cricetulus Cricetus Mesocricetus †Neocricetodon Nothocricetulus Phodopus †Rotundomys †Symmetrodontomys Tscherskia Urocricetus †Democricetodontinae Democricetodon Karydomys Spanocricetodon Neotominae †Protorepomys †Tsaphanomys Baiomyini Baiomys Scotinomys Neotomini Hodomys Nelsonia Neotoma Xenomys Ochrotomyini Ochrotomys Reithrodontomyini Habromys Isthmomys Megadontomys Neotomodon Onychomys Osgoodomys Peromyscus Podomys Reithrodontomys Sigmodontinae †Cordimus Juliomys †Megaoryzomys Oryzomyalia Abrotrichini Abrothrix Chlelemys Geoxus Notiomys Akodontini Akodon Bibimys Blarinomys Brucepattersonius Deltamys Juscelinomys Kunsia Lenoxus Necromys Neomicroxus Oxymycterus Podoxymys Scapteromys Thalpomys Thaptomys Ozyzomyini Aegialomys Amphinectomys Cerradomys Drymoreomys Eremoryzomys Euryoryzomys Handleyomys Holochilus Hylaeamys Lundomys †Megalomys Melanomys Microakodontomys Microryzomys Mindomys Neacomys Nectomys Nephelomys Nesoryzomys Noronhomys Oecomys Oligoryzomys Oreoryzomys Oryzomys Pseudoryzomys Scolomys Sigmodontomys Sooretamys Tanyuromys Transandinomys Zygodontomys Phyllotini Andalgalomys Andinomys Auliscomys Calassomys Calomys Chinchillula Eligmodontia Euneomys Galenomys Graomys †Ichthyurodon Irenomys Loxodontomys Neotomys †Olympicomys Phyllotis Punomys Reithrodon Salinomys †Tafimys Tapecomys Thomasomyini Abrawayaomys Aepeomys Chilomys Delomys Phaenomys Rhagomys Rhipidomys Thomasomys Wilfredomys Wiedomyini †Cholomys Wiedomys Sigmodontalia Ichthyomyini Anotomys Chibchanomys Daptomys Ichthyomys Neusticomys Rheomys Sigmodontini †Prosigmodon Sigmodon Tylomyinae Nyctomyini Nyctomys Ototylomys Tylomyini Otonyctomys Tylomys Muridae Deomyinae Acomys Deomys Lophuromys Uranomys Gerbillinae Ammodillus Desmodilliscini Desmodilliscus Pachyuromys Gerbillini Brachiones Dipodillus Gerbillus Meriones Microdillus Psammomys Rhombomys Sekeetamys Gerbillurini Desmodillus Gerbilliscus Gerbillurus Tatera Taterillini Taterillus Leimacomyinae Leimacomys Lophiomyinae Lophiomys Murinae †Alormys †Coryphomys Hadromys †Hoojieromys †Milimonggamys †Rakasamys †Spelaeomys Vernaya Apodemini Apodemus †Rhagamys Tokudaia Arvicanthini Aethomys Arvicanthis †Canariomys Dasymys Dephomys Desmomys Golunda Grammomys Hybomys Lamottemys Lemniscomys †Malpaisomys Micaelamys Mylomys Oenomys †Parapelomys Pelomys Rhabdomys †Saharamys †Saidomys Stochomys Thallomys Thamnomys Typomys Hapalomyini Hapalomys Hydromyini Anisomys Apomys Archboldomys Baiyankamys Brassomys Chiropodomys Chiruromys Chrotomys Coccymys Conilurus Crossomys Haeromys Hydromys Hyomys Leggadina Leporillus Leptomys Lorentzimys Macruromys Mallomys Mastacomys Melomys Mesembriomys Microhydromys Mirzamys Notomys Parahydromys Paraleptomys Paramelomys Pogonomys Protochromys Pseudohydromys Pseudomys Rhynchomys Solomys Soricomys Uromys Xeromys Zyzomys Malacomyini Malacomys Millardini Cremnomys Diomys Madromys Millardia Pithecheir Pithecheirops Murini Mus Otomyini Myotomys Otomys Parotomys Phloeomyini Batomys Carpomys Crateromys Musseromys Phloeomys Praomyini Chingawaemys Colomys Congomys Heimyscus Hylomyscus Mastomys Montemys Myomyscus Nilopegamys Ochromyscus Praomys Serengetimys Stenocephalemys Zelotomys Rattini Abditomys Anonymomys Bandicota Berylmys Bullimus Bunomys Chiromyscus Crunomys Dacnomys Diplothrix Echiothrix Eropeplus Halmaheramys Hyorhinomys Kadarsanomys Komodomys Lenomys Lenothrix Leopoldamys Limnomys Margaretamys Maxomys Melasmothrix Micromys Nesokia Nesoromys Niviventer Papagomys Palawanomys Paruromys Paucidentomys Paulamys Rattus Saxatilomys Sommeromys Srilankamys Sundamys Taeromys Tarsomys Tateomys Tonkinomys Tryphomys Waiomys Vandeleurini Vandeleuria †Pseudocricetodontinae Adelomyarion Cincamyarion Heterocricetodon Latocricetodon Lignitella Kerosinia Oxynocricetodon Pseudocricetodon Nesomyidae Cricetomyinae Beamys Cricetomys Saccostomus Delanymyinae Delanymys Dendromurinae Dendromus Dendroprionomys Malacothrix Megadendromus Prionomys Steatomys Mystromyinae Mystromys Nesomyinae Brachytarsomys Brachyuromys Eliurus Gymnuromys Hypogeomys Macrotarsomys Monticolomys Nesomys Voalavo Petromyscinae Petromyscus

• Old World rats and mice
• Rodents of Europe
• Pleistocene rodents
• Rodent genera
• Taxa named by Charles Immanuel Forsyth Major
• Extinct rodents
• Mammals described in 1856
• Fossil taxa described in 1856