Synonyms: Triakis angustidens
Original description species: (CAPPETTA, 1973)
Genus: Iago COMPAGNO & SPRINGER, 1971
Family: Triakidae GRAY, 1851
Order: Carcharhiniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Rhinobatos beurleni
Original description species: (SANTOS, 1968)
Genus: Iansan BRITO & SERET, 1996
Family: Rhinobatidae MÜLLER & HENLE, 1838
Suborder: Rhinobatoidei
Order: Rajiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: KRIWET, NUNN & KLUG, 2009
Genus: Iberotrygon KRIWET, NUNN & KLUG, 2009
Family: incert. fam.
Order: Sclerorhynchiformes
Superorder: Pristiorajea
Subclass: Elasmobranchii

Synonyms: Igdabatis cf. indicus
Original description species: PRASAD & CAPPETTA, 1993
Genus: Igdabatis CAPPETTA, 1972
Family: Myliobatidae BONAPARTE, 1838
Order: Myliobatiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: CAPPETTA, 1972
Genus: Igdabatis CAPPETTA, 1972
Family: Myliobatidae BONAPARTE, 1838
Order: Myliobatiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Pristiophorus ensifer, Trygon ensifer
Original description species: (DAVIS, 1888)
Genus: Ikamauius KEYES, 1979
Family: Pristiophoridae BLEEKER, 1859
Order: Pristiophoriformes
Superorder: Squalomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Iniopera cf. richardsoni
Original description species: ZANGERL & CASE, 1973
Genus: Iniopera ZANGERL & CASE, 1973
Family: Sibyrhynchidae ZANGERL & CASE, 1973
Order: Iniopterygiformes
Subclass: Holocephali

Synonyms: Iniopteryx cf. rushlaui
Original description species: ZANGERL & CASE, 1973
Genus: Iniopteryx ZANGERL & CASE, 1973
Family: Iniopterygidae ZANGERL & CASE, 1973
Order: Iniopterygiformes
Subclass: Holocephali

Original description species: ZANGERL & CASE, 1973
Genus: Iniopteryx ZANGERL & CASE, 1973
Family: Iniopterygidae ZANGERL & CASE, 1973
Order: Iniopterygiformes
Subclass: Holocephali

Original description species: ZANGERL & CASE, 1973
Genus: Inioxyele ZANGERL & CASE, 1973
Family: Sibyrhynchidae ZANGERL & CASE, 1973
Order: Iniopterygiformes
Subclass: Holocephali

Original description species: IVANOV, NESTELL & NESTELL, 2012
Genus: Isacrodus IVANOV, NESTELL & NESTELL, 2012
Family: Jalodontidae GINTER, HAIRAPETIAN & KLUG, 2002
Order: Phoebodontiformes
Subclass: Elasmobranchii

Original description species: CUNY, SUTEETHORN, KAMHA, BUFFETAUT & PHILIPPE, 2006
Genus: Isanodus CUNY, SUTEETHORN, KAMHA, BUFFETAUT & PHILIPPE, 2006
Family: Lonchidiidae HERMAN, 1977
Superfamily: Hybodontoidea
Order: Hybodontiformes
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Ischyodus cf. beaumonti
Original description species: EGERTON, 1843
Genus: Ischyodus EGERTON, 1843
Family: Edaphodontidae OWEN, 1846
Order: Chimaeriformes
Subclass: Holocephali

Original description species: CASE, 1978
Genus: Ischyodus EGERTON, 1843
Family: Edaphodontidae OWEN, 1846
Order: Chimaeriformes
Subclass: Holocephali

Valid name: Ischyodus acutus
Original description species: MEYER, 1859
Genus: Ischyodus EGERTON, 1843
Family: Edaphodontidae OWEN, 1846
Order: Chimaeriformes
Subclass: Holocephali

Synonyms: Chimaera (Ganodus) colei
Original description species: (AGASSIZ, 1843)
Genus: Ischyodus EGERTON, 1843
Family: Edaphodontidae OWEN, 1846
Order: Chimaeriformes
Subclass: Holocephali

Synonyms: Ischyodus cf. dolloi
Original description species: LERICHE, 1902
Genus: Ischyodus EGERTON, 1843
Family: Edaphodontidae OWEN, 1846
Order: Chimaeriformes
Subclass: Holocephali

Synonyms: Chimaera (Ischyodon) emarginata, Ischyodon emarginata
Original description species: EGERTON, 1843
Genus: Ischyodus EGERTON, 1843
Family: Edaphodontidae OWEN, 1846
Order: Chimaeriformes
Subclass: Holocephali

Original description species: CHAPMAN & PRITCHARD, 1907
Genus: Ischyodus EGERTON, 1843
Family: Edaphodontidae OWEN, 1846
Order: Chimaeriformes
Subclass: Holocephali

Original description species: AVERIANOV, 1992
Genus: Ischyodus EGERTON, 1843
Family: Edaphodontidae OWEN, 1846
Order: Chimaeriformes
Subclass: Holocephali

Original description species: HOGANSON & ERICKSON, 2005
Genus: Ischyodus EGERTON, 1843
Family: Edaphodontidae OWEN, 1846
Order: Chimaeriformes
Subclass: Holocephali

Synonyms: Ischyodus cf. schuebleri
Original description species: QUENSTEDT, 1858
Genus: Ischyodus EGERTON, 1843
Family: Edaphodontidae OWEN, 1846
Order: Chimaeriformes
Subclass: Holocephali

Original description species: CASE, 1991
Genus: Ischyodus EGERTON, 1843
Family: Edaphodontidae OWEN, 1846
Order: Chimaeriformes
Subclass: Holocephali

Synonyms: Ischyrhiza aff. avonicola, Ischyrhiza cf. avonicola, Ischyrhiza germaniae, Sclerorhynchus germaniae
Original description species: ESTES, 1964
Genus: Ischyrhiza LEIDY, 1856
Family: Sclerorhynchidae CAPPETTA, 1974
Suborder: Sclerorhynchoidei
Order: Rajiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: (PHILIPPI, 1887)
Genus: Ischyrhiza LEIDY, 1856
Family: Sclerorhynchidae CAPPETTA, 1974
Suborder: Sclerorhynchoidei
Order: Rajiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: CASE, SCHWIMMER, BORODIN & LEGGETT, 2001
Genus: Ischyrhiza LEIDY, 1856
Family: Sclerorhynchidae CAPPETTA, 1974
Suborder: Sclerorhynchoidei
Order: Rajiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: CAPPETTA, 1975
Genus: Ischyrhiza LEIDY, 1856
Family: Sclerorhynchidae CAPPETTA, 1974
Suborder: Sclerorhynchoidei
Order: Rajiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Ischyrhiza aff. mira, Ischyrhiza antiqua, Onchosaurus (Ischyrhiza) antiquus
Original description species: LEIDY, 1856
Genus: Ischyrhiza LEIDY, 1856
Family: Sclerorhynchidae CAPPETTA, 1974
Suborder: Sclerorhynchoidei
Order: Rajiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: SLAUGHTER & STEINER, 1968
Genus: Ischyrhiza LEIDY, 1856
Family: Sclerorhynchidae CAPPETTA, 1974
Suborder: Sclerorhynchoidei
Order: Rajiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: CASE & CAPPETTA, 1997
Genus: Ischyrhiza LEIDY, 1856
Family: Sclerorhynchidae CAPPETTA, 1974
Suborder: Sclerorhynchoidei
Order: Rajiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: (SLAUGHTER & SCHNEIDER, 1968)
Genus: Ischyrhiza LEIDY, 1856
Family: Sclerorhynchidae CAPPETTA, 1974
Suborder: Sclerorhynchoidei
Order: Rajiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: CAPPETTA, 1981
Genus: Ischyrhiza LEIDY, 1856
Family: Sclerorhynchidae CAPPETTA, 1974
Suborder: Sclerorhynchoidei
Order: Rajiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Dasyatis globidens
Original description species: (ARAMBOURG, 1952)
Genus: Ishaquia NOUBHANI & CAPPETTA, 1995
Family: Dasyatidae JORDAN, 1888
Order: Myliobatiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Centrina dertonensis, Isistius aff. triangulus, Isistius cf. triangulus, Isistius dertonensis, Scymnus triangulus
Original description species: (PROBST, 1879)
Genus: Isistius GILL, 1865
Family: Dalatiidae GRAY, 1851
Order: Squaliformes
Superorder: Squalomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Corax trituratus, Isistius aff. trituratus, Isistius cf. trituratus, Scymnus trituratus
Original description species: (WINKLER, 1876)
Genus: Isistius GILL, 1865
Family: Dalatiidae GRAY, 1851
Order: Squaliformes
Superorder: Squalomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Alopecias acuarias, Aprionodon acuarias, Aprionodon acuarius, Carcharhinus acuarius, Carcharhinus (Aprionodon) gracilis, Carcharhinus (Aprionodon) lerichei minuta, Isogomphodon gracilis
Original description species: (PROBST, 1879)
Genus: Isogomphodon GILL, 1862
Family: Carcharhinidae JORDAN & EVERMANN, 1896
Order: Carcharhiniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Aprionodon aff. caunellensis, Aprionodon caunellensis
Original description species: (CAPPETTA, 1970)
Genus: Isogomphodon GILL, 1862
Family: Carcharhinidae JORDAN & EVERMANN, 1896
Order: Carcharhiniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Isurolamna hopei affinis, Lamiostoma affinis, Odontaspis hopei affinis
Original description species: (CASIER, 1946)
Genus: Isurolamna CAPPETTA, 1976
Family: Lamnidae MÜLLER & HENLE, 1838
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Lamiostoma bajarunasi
Original description species: (GLIKMAN & ZHELEZKO, 1985)
Genus: Isurolamna CAPPETTA, 1976
Family: Lamnidae MÜLLER & HENLE, 1838
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: (LE HON, 1871)
Genus: Isurolamna CAPPETTA, 1976
Family: Lamnidae MÜLLER & HENLE, 1838
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Lamna inflata, Lamna vincenti inflata
Original description species: (LERICHE, 1905)
Genus: Isurolamna CAPPETTA, 1976
Family: Lamnidae MÜLLER & HENLE, 1838
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Isurus cf. desori, Isurus desorii, Isurus inequilateralis, Lamiostoma desori, Lamna desori, Lamna inequilateralis, Lamna lyellii, Oxyrhina cf. desori, Oxyrhina desori, Oxyrhina desorii
Original description species: (AGASSIZ, 1843)
Genus: Isurus RAFINESQUE, 1810
Family: Lamnidae MÜLLER & HENLE, 1838
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Cosmopolitodus flandricus, Isurus aff. desori flandrica, Isurus aff. flandricus, Isurus desori flandrica, Isurus desori flandricus, Macrorhizodus flandricus, Oxyrhina desori flandrica
Original description species: (LERICHE, 1910)
Genus: Isurus RAFINESQUE, 1810
Family: Lamnidae MÜLLER & HENLE, 1838
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Oxyrhina minuta
Original description species: (AGASSIZ, 1843)
Genus: Isurus RAFINESQUE, 1810
Family: Lamnidae MÜLLER & HENLE, 1838
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: SAITO, 1961
Genus: Isurus RAFINESQUE, 1810
Family: Lamnidae MÜLLER & HENLE, 1838
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Oxyrhina plana
Original description species: (AGASSIZ, 1856)
Genus: Isurus RAFINESQUE, 1810
Family: Lamnidae MÜLLER & HENLE, 1838
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Synonyms: Cosmopolitodus praecursor, Cosmopolitodus (Isurus) praecursor, Isurus cf. praecursor, Macorhizodus praecursor, Macrorhizodus praecursor, Otodus lawleyi, Oxyrhina desori praecursor, Oxyrhina latus, Oxyrhina praecursor
Original description species: (LERICHE, 1905)
Genus: Isurus RAFINESQUE, 1810
Family: Lamnidae MÜLLER & HENLE, 1838
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: MEHROTRA, MISHRA & SRIVASTAVA, 1973
Genus: Isurus RAFINESQUE, 1810
Family: Lamnidae MÜLLER & HENLE, 1838
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Valid name: Cosmopolitodus hastalis
Original description species: JORDAN, 1907
Genus: Isurus RAFINESQUE, 1810
Family: Lamnidae MÜLLER & HENLE, 1838
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Original description species: SILVA SANTOS, 1990

Synonyms: Raja mucronata
Original description species: (ARAMBOURG, 1952)
Genus: Ixobatis NOUBHANI & CAPPETTA, 1995
Family: incert. fam.
Order: Myliobatiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii