PBDB Taxon

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Morphology	Ecology and taphonomy	External Literature Search	Age range and collections

Ischyromyidae

Osteichthyes - Rodentia - Ischyromyidae

Taxonomy

Ischyromyidae was named by Alston (1876). It is not extant.

It was assigned to Sciuromorpha by Hay (1902); to Simplicidentata by Flower and Lydekker (1891), Lambe (1908); to Protrogomorpha by Wood (1958); to Protrogomorpha by McKenna and Bell (1997); to Sciuromorpha by Dunn and Rasmussen (2007); and to Rodentia by Korth (2014), Lofgren et al. (2020), Korth et al. (2022).

Subtaxa

Acritoparamys, Ailuravinae, Apatosciuravus, Churcheria (syn. Anonymus), Decticadapis, Hulgana, Ischyromyinae, Ischyromys (syn. Colotaxis, Gymnoptychus, Titanotheriomys), Lophiparamys, Microparamyinae, Notoparamys, Paramyinae, Pseudoparamyinae, Rapamys, Tapomys, Thisbemys, Uintaparamys (syn. Leptotomus)

Entered

by J. Alroy on 2003-01-23; modified by B. Allen on 2023-07-21

Synonymy list

Year	Name and author
1876	Ischyromyidae Alston
1891	Ischyromyidae Flower and Lydekker p. 91
1902	Ischyromyidae Hay p. 723
1908	Ischyromyidae Lambe
1958	Ischyromyidae Wood p. 172
1997	Ischyromyidae McKenna and Bell
2007	Ischyromyidae Dunn and Rasmussen p. 988
2014	Ischyromyidae Korth p. 374
2020	Ischyromyidae Lofgren et al.
2022	Ischyromyidae Korth et al.

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Rank	Name	Author
kingdom	Animalia	()
—	Bilateria
—	Eubilateria	Ax 1987
—	Deuterostomia
phylum	Chordata	Haeckel 1874
subphylum	Vertebrata
superclass	Gnathostomata
class	Osteichthyes
subclass	Sarcopterygii	()
subclass	Dipnotetrapodomorpha	(Nelson 2006)
subclass	Tetrapodomorpha	()
—	Tetrapoda
—	Reptiliomorpha
—	Anthracosauria
subclass	Amphibiosauria	Kuhn 1967
—	Cotylosauria	()
—	Amniota
subclass	Synapsida
—	Therapsida	()

Rank	Name	Author
infraorder	Cynodontia	()
—	Mammaliamorpha
—	Mammaliaformes
class	Mammalia
—	Cladotheria
—	Zatheria
subclass	Tribosphenida	()
subclass	Theria
—	Eutheria	()
—	Placentalia
—	Boreoeutheria
—	Euarchontoglires	Murphy et al. 2001
—	Gliriformes	Wyss and Meng 1996
—	Glires	()
—	Simplicidentata	()
order	Rodentia
family	Ischyromyidae	Alston 1876
family	Ischyromyidae	Alston 1876

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

Fm. †Ischyromyidae Alston 1876

show all | hide all

G. †Acritoparamys Korth 1984

†Acritoparamys atavus Jepsen 1937

†Acritoparamys atwateri Loomis 1907

Invalid names: Paramys annectens Rose 1981 [synonym]

†Acritoparamys francesi Wood 1962

†Acritoparamys pattersoni Wood 1962

†Acritoparamys wutui Tong and Dawson 1995

Subfm. †Ailuravinae Michaux 1968

G. †Ailuravus Rütimeyer 1891

†Ailuravus macrurus Weitzel 1949

†Ailuravus michauxi Hartenberger 1975

†Ailuravus mitchelli Hooker 2010

†Ailuravus picteti Rütimeyer 1891

†Ailuravus stehlinschaubi Wood 1976

†Ailuravus subita Comte et al. 2012

Invalid names: Aeluravus Stehlin and Schaub 1951 [synonym], Maurimontia Stehlin and Schaub 1951 [synonym], Palaeomarmota Haupt 1921 [synonym]

G. †Eohaplomys Stock 1935

†Eohaplomys matutinus Stock 1935

†Eohaplomys serus Stock 1935

†Eohaplomys tradux Stock 1935

G. †Euromys Escarguel 1999

†Euromys cardosoi Estravís 2000

G. †Meldimys Michaux 1968

†Meldimys musak Rana et al. 2008

G. †Mytonomys Wood 1956

†Mytonomys burkei Wilson 1940

†Mytonomys coloradensis Wood 1962

Invalid names: Leptotomus loomisi Wood 1962 [synonym]

†Mytonomys gaitania Ferrusquia-Villafranca and Wood 1969

†Mytonomys mytonensis Wood 1962

†Mytonomys robustus Peterson 1919

Invalid names: Leptotomus kayi Burke 1934 [synonym]

†Mytonomys wortmani Wood 1962

G. †Apatosciuravus Korth 1984

†Apatosciuravus bifax Korth 1984

†Apatosciuravus jacobsi Flanagan 1986

G. †Churcheria Storer 2002

†Churcheria baroni Storer 1988

Invalid names: Anonymus Storer 1988 [synonym]

G. †Decticadapis Lemoine 1891

†Decticadapis sciuroides Lemoine 1891

G. †Hulgana Dawson 1962

†Hulgana eoertinia Tong 1997

Subfm. †Ischyromyinae Schlosser 1911

G. †Eosischyromys Wang et al. 1998

†Eosischyromys youngi Wang et al. 1998

G. †Proischyromys Samuels and Korth 2017

†Proischyromys perditus Samuels and Korth 2017

G. †Ischyromys Leidy 1856

†Ischyromys blacki Wood 1974

†Ischyromys brevidens Korth et al. 2022

†Ischyromys douglassi Black 1968

†Ischyromys junctus Russell 1972

†Ischyromys typus Leidy 1856

Invalid names: Colotaxis cristatus Cope 1873 [synonym], Gymnoptychus chrysodon Cope 1873 [synonym], Ischyromys pliacus Troxell 1922 [synonym], Ischyromys troxelli Wood 1937 [synonym], Ischyromys typus lloydi Troxell 1922 [invalid subgroup]

†Ischyromys veterior Matthew 1903

Invalid names: Titanotheriomys wyomingensis Wood 1937 [synonym]

Invalid names: Colotaxis Cope 1873 [synonym], Gymnoptychus Cope 1873 [synonym], Ischyromys parvidens Miller and Gidley 1920 [nomen dubium], Ischyromys typus nanus Troxell 1922 [nomen dubium], Titanotheriomys Miller and Gidley 1920 [synonym]

G. †Lophiparamys Wood 1962

†Lophiparamys debequensis Wood 1962

†Lophiparamys murinus Matthew 1918

†Lophiparamys woodi Guthrie 1971

Subfm. †Microparamyinae Wood 1962

G. †Hartenbergeromys Escarguel 1999

G. †Masillamys Tobien 1954

G. †Mattimys Korth 1984

†Mattimys kalicola Matthew 1918

G. †Microparamys Wood 1959

†Microparamys bayi Dawson 2001

†Microparamys chandoni Hartenberger 1971

†Microparamys cheradius Ivy 1990

†Microparamys dubius Wood 1949

†Microparamys hottingeri Marandat 1989

†Microparamys hunterae Ivy 1990

†Microparamys lingchaensis Li et al. 1979

†Microparamys minutus Wilson 1937

†Microparamys nanus Teilhard de Jardin 1927

†Microparamys nimius Storer 1988

†Microparamys paisi Estravís 1994

†Microparamys perfossus Wood 1974

†Microparamys sambucus Korth and Emry 1989

†Microparamys scopaiodon Korth 1984

†Microparamys solidus Storer 1984

†Microparamys solis Dawson and Constenius 2018

†Microparamys tricus Wilson 1940

†Microparamys woodi Kelly and Whistler 1994

G. †Pantrogna Hartenberger 1971

†Pantrogna marandati Escarguel 1999

†Pantrogna russelli Michaux 1964

G. †Sparnacomys Hartenberger 1971

†Sparnacomys chandoni Hartenberger 1971

†Sparnacomys georgei Hooker 2010

G. †Strathcona Dawson 2001

†Strathcona major Dawson 2001

†Strathcona minor Dawson 2001

G. †Notoparamys Korth 1984

†Notoparamys arctios Korth 1984

†Notoparamys blochi Gunnell et al. 2016

†Notoparamys costilloi Wood 1962

Subfm. †Paramyinae Simpson 1945

G. †Abrosomys Shevyreva 1984

†Abrosomys agasma Shevyreva 1984

Tr. †Manitshini Simpson

G. †Manitsha Simpson 1941

†Manitsha tanka Simpson 1941

G. †Plesiarctomys Bravard 1848

†Plesiarctomys curranti Hooker 1986

†Plesiarctomys gervaisii Bravard 1850

†Plesiarctomys hartenbergeri Wood 1970

†Plesiarctomys huerzeleri Wood 1970

G. †Pseudotomus Cope 1872

†Pseudotomus californicus Wilson 1940

†Pseudotomus eugenei Burke 1935

†Pseudotomus hians Cope 1872

Invalid names: Paramys superbus Osborn et al. 1878 [synonym]

†Pseudotomus horribilis Wood 1962

†Pseudotomus johanniculi Wood 1974

†Pseudotomus littoralis Wilson 1949

†Pseudotomus petersoni Matthew 1910

†Pseudotomus robustus Marsh 1872

Invalid names: Ischyrotomus oweni Wood 1962 [synonym]

†Pseudotomus timmys Storer 1988

Invalid names: Ischyrotomus Matthew 1910 [synonym]

G. †Metaparamys Korth and Emry 2007

†Metaparamys compressidens Peterson 1919

†Metaparamys dawsonae Korth and Emry 2007

Tr. †Paramyini Simpson 1945

G. †Quadratomus Korth 1984

†Quadratomus gigans Wood 1974

†Quadratomus grandis Wood 1962

†Quadratomus grossus Korth 1985

†Quadratomus sundelli Eaton 1982

G. †Paramys Leidy 1871

Subg. †Paramys (Leptotomus) Matthew 1910

†Paramys adamus Dawson and Beard 1996

†Paramys copei Loomis 1907

†Paramys copei copei Loomis 1907

Invalid names: Paramys bicuspis Loomis 1907 [synonym], Paramys major Loomis 1907 [synonym], Paramys primaevus Loomis 1907 [synonym], Paramys quadratus Loomis 1907 [synonym]

†Paramys delicatior Leidy 1871

†Paramys delicatus Leidy 1871

†Paramys dispar Beard and Dawson 2009

†Paramys excavatus Loomis 1907

†Paramys excavatus excavatus Loomis 1907

†Paramys excavatus taurus Wood 1962

Invalid names: Franimys lysitensis Guthrie 1967 [synonym]

†Paramys hunti Dawson 2001

†Paramys nini Wood 1962

†Paramys obailensis Shevyreva 1984

†Paramys pourcyensis Michaux 1964

†Paramys pycnus Ivy 1990

†Paramys savagei Micheau 1964

†Paramys simpsoni Korth 1984

†Paramys taurus Korth 1984

†Paramys teilhardi Wood 1962

†Paramys wyomingensis Wood 1959

Invalid names: Reithroparamys matthewi Wood 1962 [synonym]

Invalid names: Paramys excavatus obliquidens Wood 1962 [synonym]

Subfm. †Pseudoparamyinae Michaux 1964

G. †Patriarchamys Harrison 2006

†Patriarchamys batesi Harrison 2006

G. †Rapamys Wilson 1940

†Rapamys atramontis Wahlert et al. 2006

†Rapamys fricki Wilson 1940

†Rapamys wilsoni Black 1971

G. †Tapomys Wood 1962

†Tapomys tapensis Wilson 1940

G. †Thisbemys Wood 1959

†Thisbemys brevicrista Ostrander 1986

†Thisbemys corrugatus Wood 1959

Invalid names: Thisbemys plicatus Wood 1962 [synonym]

†Thisbemys elachistos Korth 1984

†Thisbemys intermedius Korth 2020

†Thisbemys perditus Wood 1962

Invalid names: Leptotomus huerfanensis Wood 1962 [synonym], Paramys excavatus gardneri Wood 1962 [synonym]

†Thisbemys uintensis Osborn 1895

Invalid names: Thisbemys medius Peterson 1919 [synonym]

G. †Uintaparamys Kretzoi 1968

†Uintaparamys bridgerensis Wood 1962

†Uintaparamys caryophilus Wilson 1940

†Uintaparamys coelumensis Wilson and Stevens 1986

†Uintaparamys grangeri Matthew 1910

†Uintaparamys leptodus Cope 1873

†Uintaparamys parvus Wood 1959

Invalid names: Leptotomus Matthew 1910 [replaced]

Diagnosis

No diagnoses are available

Measurements

No measurements are available

Composition:

phosphaticsubp

Maximum body mass:

1 kgg

Minimum body mass:

1 kgg

Body mass estimate:

1 kg

Environment:

terrestrialsubc

Locomotion:

actively mobilec

Life habit:

ground dwellingo

Diet:

herbivoreo

Reproduction:

viviparoussubc

Created:

2005-08-26 14:04:46

Modified:

2005-08-26 16:04:46

Source: g = genus, o = order, subc = subclass, c = class, subp = subphylum

References: Lillegraven 1979, Carroll 1988, Ji et al. 2002, Nowak 1999, Hendy et al. 2009, Legendre 1988

Age range: base of the Clarkforkian to the top of the Whitneyan or 57.50000 to 29.50000 Ma

Collections (672 total)

Time interval	Ma	Country or state	Original ID and collection number
Oldest occurrences
Late/Upper Paleocene	59.24 - 56.0	France (Oise)	Ischyromyidae indet. (166598)
Late/Upper Paleocene - Early/Lower Eocene	59.24 - 48.07	USA (Wyoming)	Microparamys cheradius (80579)
Clarkforkian	57.5 - 56.0	USA (Montana)	Paramys atavus (15079)
Clarkforkian	57.5 - 56.0	USA (Wyoming)	Acritoparamys atavus (190416) Acritoparamys atwateri (239208) Acritoparamys atwateri, Microparamys cheradius, Paramys taurus, Microparamys sp. (15085) Ischyromyidae indet., Paramys excavatus (15092) Paramys annectens (15197) Paramys atavus (15072) Paramys sp. (15075 15083 15094) Rodentia indet. (15216)
Clarkforkian	57.5 - 56.0	USA (Colorado)	Paramys excavatus, Reithroparamys sp. (15346 15347)
Graybullian	56.0 - 51.1	USA (Wyoming)	Acritoparamys atwateri, Microparamys cheradius, Paramys copei, Paramys taurus (15701)
Lostcabinian	56.0 - 51.1	USA (Wyoming)	Ischyromyidae indet., Microparamys sp., Acritoparamys francesi, Mattimys kalicola, Paramys copei, Paramys excavatus (15930) Ischyromyidae indet., Paramys copei (16073) Microparamys sp., Thisbemys sp., Mattimys sp., Paramys copei (15917) Paramys copei (15901 16005 16078) Paramys copei, Paramys excavatus (15915)
Lysitean	56.0 - 51.1	USA (Wyoming)	Paramys copei (15880)
Lysitean - Lostcabinian	56.0 - 51.1	USA (Wyoming)	Microparamys sp. (15451)
Wasatchian	56.0 - 51.1	USA (Mississippi)	Paramys atavus, Paramys adamus (15719)
Youngest occurrences
Time interval	Ma	Country or state	PBDB collection number
Middle Chadronian - Late/Upper Chadronian	37.0 - 33.9	USA (Colorado)	Ischyromys sp. (156988)
Late/Upper Chadronian - Orellan	37.0 - 31.8	USA (Nebraska)	Ischyromys brevidens (230806)
Orellan	33.9 - 31.8	USA (Wyoming)	Ischyromys parvidens (17104 17105 17106) Ischyromys pliacus (17086)
Orellan	33.9 - 31.8	USA (Nebraska)	Ischyromys parvidens (17098 17203 17225 17226 17231 17235 17247 17255 17256 17271 17273 17279 17282 17283) Ischyromys pliacus (17242 17244 17250) Ischyromys typus (17062 17108 17150 17164 17165 17212 17216 17223 17249 17253 17257 17275 17287 17297)
Orellan	33.9 - 31.8	USA (North Dakota)	Ischyromys sp. (17301) Ischyromys typus (17100 17101)
Orellan	33.9 - 31.8	USA (Colorado)	Ischyromys typus (17082) Ischyromys typus, Titanotheriomys sp. (17081)
Orellan	33.9 - 31.8	USA (Montana)	Ischyromys sp. (17090)
Orellan	33.9 - 31.8	USA (South Dakota)	Ischyromys parvidens (17162) Ischyromys pliacus (17115) Ischyromys sp. (17153 17186 17187 17188 17189 17190 17198 163487) Ischyromys sp., Manitsha tanka (17136) Ischyromys troxelli (17179) Ischyromys typus (17094 17102 17103 17133 17173 17174 17182 17295) Rodentia indet. (17089)
Whitneyan	31.8 - 29.5	USA (South Dakota)	Ischyromys pliacus (17336) Ischyromys sp. (17384) Ischyromys typus (170168)
Whitneyan	31.8 - 29.5	USA (Nebraska)	Ischyromys sp. (17414) Ischyromys typus (17427)