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Xampylodon brotzeni (9)
(Siverson, 1995)
Synonyms: Notidanodon brotzeni, Notidanodon cf. brotzeni
Original description species: (Siverson, 1995)
Genus: Xampylodon Cappetta, Morrison & Adnet, 2019
Family: Hexanchidae Gray, 1851
Suborder: Hexanchoidei
Order: Hexanchiformes
Superorder: Squalomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xampylodon dentatus (25)
(Woodward, 1886)
Synonyms: Notidanodon cf. dentatus, Notidanodon dentatus, Notidanus dentatus, Notorynchus dentatus
Original description species: (Woodward, 1886)
Genus: Xampylodon Cappetta, Morrison & Adnet, 2019
Family: Hexanchidae Gray, 1851
Suborder: Hexanchoidei
Order: Hexanchiformes
Superorder: Squalomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xampylodon diastemacron (1)
Otávio dos Santos, Riff, Ramos, Rodrigues, Scheffler, Sucerquia & de Araújo Carvalho, 2024
Original description species: Otávio dos Santos, Riff, Ramos, Rodrigues, Scheffler, Sucerquia & de Araújo Carvalho, 2024
Genus: Xampylodon Cappetta, Morrison & Adnet, 2019
Family: Hexanchidae Gray, 1851
Suborder: Hexanchoidei
Order: Hexanchiformes
Superorder: Squalomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xampylodon loozi (31)
(Vincent, 1876)
Synonyms: Notidanodon cf. loozi, Notidanodon looi, Notidanodon loozi, Notidanus loozi, Notidanus (Hexanchus) loozi
Original description species: (Vincent, 1876)
Genus: Xampylodon Cappetta, Morrison & Adnet, 2019
Family: Hexanchidae Gray, 1851
Suborder: Hexanchoidei
Order: Hexanchiformes
Superorder: Squalomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xenacanthus acinaces (3)
(Dawson, 1860)
Synonyms: Diplodus acinaces, Dittodus acinaces
Original description species: (Dawson, 1860)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus aff. texensis (1)
(Cope, 1888)
Valid name: Orthacanthus texensis
Valid name: Orthacanthus texensis
Original description species: (Cope, 1888)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus albuquerquei (3)
(Silva Santos, 1946)
Valid name: Taquaralodus albuquerquei
Valid name: Taquaralodus albuquerquei
Original description species: (Silva Santos, 1946)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus carinatus (1)
(Fritsch, 1890)
Valid name: Triodus carinatus
Valid name: Triodus carinatus
Original description species: (Fritsch, 1890)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus cf. compressus (1)
(Newberry, 1856)
Valid name: Orthacanthus compressus
Valid name: Orthacanthus compressus
Original description species: (Newberry, 1856)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus cf. ossiani (1)
Johnson, 1999
Valid name: Xenacanthus ossiani
Valid name: Xenacanthus ossiani
Original description species: Johnson, 1999
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus compressus (2)
(Newberry, 1856)
Valid name: Orthacanthus compressus
Valid name: Orthacanthus compressus
Original description species: (Newberry, 1856)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus decheni (31)
(Goldfuss, 1847)
Synonyms: Orthacanthus dechenii, Pleuracanthus decheni, Pleuracanthus (Xenacanthus) decheni
Original description species: (Goldfuss, 1847)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus elegans (5)
(Traquair, 1881)
Synonyms: Pleuracanthus elegans
Original description species: (Traquair, 1881)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus gaudryi (2)
(Brongniart & Sauvage, 1888)
Synonyms: Pleuracanthus gaudryi
Original description species: (Brongniart & Sauvage, 1888)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus gracilis (3)
(Newberry, 1856)
Valid name: Orthacanthus lintonensis
Valid name: Orthacanthus lintonensis
Original description species: (Newberry, 1856)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus humbergensis (5)
Hampe, 1994
Original description species: Hampe, 1994
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus laevissimus (16)
(Agassiz, 1837)
Synonyms: Compsacanthus major, Dittodus divergens, Expleuracanthus laevissimus, Pleuracanthus erectus, Pleuracanthus laevissimus, Pleuracanthus planus, Pleuracanthus woodwardi, Pleuracanthus (Diplodus) laevissimus, Pternodus productus
Original description species: (Agassiz, 1837)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus latus (5)
(Newberry & Worthen, 1866)
Synonyms: Diplodus latus, Orthacanthus cf. latus
Original description species: (Newberry & Worthen, 1866)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus levidens (1)
Fritsch, 1875
Original description species: Fritsch, 1875
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus luedersensis (9)
Berman, 1970
Valid name: Barbclabornia luedersensis
Valid name: Barbclabornia luedersensis
Original description species: Berman, 1970
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus meisenheimensis (11)
Hampe, 1994
Original description species: Hampe, 1994
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus moorei (13)
(Woodward, 1889)
Valid name: Mooreodontus moorei
Valid name: Mooreodontus moorei
Original description species: (Woodward, 1889)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus nebraskensis (5)
Johnson, 1984
Valid name: Bransonella nebraskensis
Valid name: Bransonella nebraskensis
Original description species: Johnson, 1984
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus oelbergensis (3)
(Fritsch, 1890)
Original description species: (Fritsch, 1890)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus ossiani (2)
Johnson, 1999
Synonyms: Xenacanthus cf. ossiani
Original description species: Johnson, 1999
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus ovalis (8)
(Fritsch, 1890)
Synonyms: Pleuracanthus ovalis
Original description species: (Fritsch, 1890)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus paralellus (1)
(Fritsch, 1890)
Valid name: Xenacanthus parallelus
Valid name: Xenacanthus parallelus
Original description species: (Fritsch, 1890)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus parallelus (13)
(Fritsch, 1890)
Synonyms: Pleuracanthus parallelus, Xenacanthus paralellus
Original description species: (Fritsch, 1890)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus parvidens (1)
(Woodward, 1908)
Valid name: Mooreodontus parvidens
Valid name: Mooreodontus parvidens
Original description species: (Woodward, 1908)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus penetrans (2)
(Dawson, 1860)
Synonyms: Dittodus penetrans
Original description species: (Dawson, 1860)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus platypternus (1)
Cope, 1884
Valid name: Orthacanthus platypternus
Valid name: Orthacanthus platypternus
Original description species: Cope, 1884
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus plicatus (2)
Fritsch, 1879
Valid name: Plicatodus plicatus
Valid name: Plicatodus plicatus
Original description species: Fritsch, 1879
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus pricei (1)
Würdig-Maciel, 1975
Original description species: Würdig-Maciel, 1975
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus ragonhai (1)
Pauliv, Dias, Sedor & Ribeiro, 2014
Original description species: Pauliv, Dias, Sedor & Ribeiro, 2014
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus remigiusbergensis (6)
Hampe, 1994
Original description species: Hampe, 1994
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus santaritensis (1)
Ragonha, 1984
Original description species: Ragonha, 1984
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus santosi (1)
Würdig-Maciel, 1975
Original description species: Würdig-Maciel, 1975
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus sessilis (1)
(Jordan, 1849)
Valid name: Triodus sessilis
Valid name: Triodus sessilis
Original description species: (Jordan, 1849)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus slaughteri (3)
Johnson, 1999
Original description species: Johnson, 1999
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus sp. (48)

Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus tenuis (4)
(Woodward, 1889)
Synonyms: Diplodus tenuis
Original description species: (Woodward, 1889)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus texensis (2)
(Cope, 1888)
Valid name: Orthacanthus texensis
Valid name: Orthacanthus texensis
Original description species: (Cope, 1888)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus tocantinsensis (2)
Santos & Salgado, 1970
Original description species: Santos & Salgado, 1970
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus tridentatus (5)
(Harlton, 1933)
Synonyms: Bransonella tridentata
Original description species: (Harlton, 1933)
Genus: Xenacanthus Beyrich, 1848
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenacanthus (Diplodus) plicatus (1)
Fritsch, 1879
Valid name: Plicatodus plicatus
Valid name: Plicatodus plicatus
Original description species: Fritsch, 1879
Genus: Xenacanthus (Diplodus)
Family: Xenacanthidae Fritsch, 1889
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenodolamia aff. simplex (1)
(Leidy, 1877)
Original description species: (Leidy, 1877)
Genus: Xenodolamia Leidy, 1877
Family: incert. fam.
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xenodolamia barbadica (2)
Casier, 1958
Valid name: Xiphodolamia barbadica
Valid name: Xiphodolamia barbadica
Original description species: Casier, 1958
Genus: Xenodolamia Leidy, 1877
Family: incert. fam.
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xenodolamia eocaena (13)
(Woodward, 1889)
Valid name: Xiphodolamia eocaena
Valid name: Xiphodolamia eocaena
Original description species: (Woodward, 1889)
Genus: Xenodolamia Leidy, 1877
Family: incert. fam.
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xenodolamia parvus (1)
Leidy, 1877
Valid name: Otodus (Megaselachus) megalodon
Valid name: Otodus (Megaselachus) megalodon
Original description species: Leidy, 1877
Genus: Xenodolamia Leidy, 1877
Family: incert. fam.
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xenodolamia pravus (2)
Leidy, 1877
Valid name: Otodus (Megaselachus) megalodon
Valid name: Otodus (Megaselachus) megalodon
Original description species: Leidy, 1877
Genus: Xenodolamia Leidy, 1877
Family: incert. fam.
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xenodolamia simplex (2)
Leidy, 1877
Original description species: Leidy, 1877
Genus: Xenodolamia Leidy, 1877
Family: incert. fam.
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xenodolamia sp. (3)

Genus: Xenodolamia Leidy, 1877
Family: incert. fam.
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xenodus hertzeri (1)
(Newberry, 1889)
Original description species: (Newberry, 1889)
Genus: Xenodus Miller, 1892
Family: Cochliodontidae Owen, 1867
Order: Cochliodontiformes
Superorder: Holocephalimorpha
Subclass: Holocephali
Xenodus herzeri (1)
(Newberry, 1889)
Original description species: (Newberry, 1889)
Genus: Xenodus Miller, 1892
Family: Cochliodontidae Owen, 1867
Order: Cochliodontiformes
Superorder: Holocephalimorpha
Subclass: Holocephali
Xenosynechodus egloni (8)
Glikman, 1980
Original description species: Glikman, 1980
Genus: Xenosynechodus Glikman, 1980
Family: Xenosynechodontidae Glickman, 1980
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xenosynechodus sp. (2)

Genus: Xenosynechodus Glikman, 1980
Family: Xenosynechodontidae Glickman, 1980
Order: Xenacanthiformes
Superorder: Xenacanthimorpha
Subclass: Elasmobranchii
Xiaohaizilepis liui (2)
Andreev, Zhao, Wang, Smith, Li, Cui, Zhu & Sansom, 2020
Original description species: Andreev, Zhao, Wang, Smith, Li, Cui, Zhu & Sansom, 2020
Genus: Xiaohaizilepis Andreev, Zhao, Wang, Smith, Li, Cui, Zhu & Sansom, 2020
Family: Shiqianolepidae Sansom, Aldridge & Smith, 2000
Order: Mongolepidida
Xinjiangichthys pluridentatus (5)
Wang, Zhang, Wang & Zhu, 1998
Original description species: Wang, Zhang, Wang & Zhu, 1998
Genus: Xinjiangichthys Wang, Zhang, Wang & Zhu, 1998
Family: Shiqianolepidae Sansom, Aldridge & Smith, 2000
Order: Mongolepidida
Xinjiangichthys tarimensis (1)
Wang, Zhang, Wang & Zhu, 1998
Original description species: Wang, Zhang, Wang & Zhu, 1998
Genus: Xinjiangichthys Wang, Zhang, Wang & Zhu, 1998
Family: Shiqianolepidae Sansom, Aldridge & Smith, 2000
Order: Mongolepidida
Xiphodolamia barbadica (3)
(Casier, 1958)
Synonyms: Xenodolamia barbadica
Original description species: (Casier, 1958)
Genus: Xiphodolamia Leidy, 1877
Family: Xiphodolamiidae Cappetta, 2012
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xiphodolamia ensis (25)
Leidy, 1877
Synonyms: Xyphodolamia ensis
Original description species: Leidy, 1877
Genus: Xiphodolamia Leidy, 1877
Family: Xiphodolamiidae Cappetta, 2012
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xiphodolamia eocaena (37)
(Woodward, 1889)
Synonyms: Carcharias (Scoliodon) eocaenus, Isurus eocaenus, Oxyrhina eocaena, Oxyrhina zignoi, Rhizoprionodon eocaenus, Xenodolamia eocaena, Xiphodolamia eocenica, Xiphodolamia zignoi
Original description species: (Woodward, 1889)
Genus: Xiphodolamia Leidy, 1877
Family: Xiphodolamiidae Cappetta, 2012
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xiphodolamia eocenica (5)
(Woodward, 1889)
Valid name: Xiphodolamia eocaena
Valid name: Xiphodolamia eocaena
Original description species: (Woodward, 1889)
Genus: Xiphodolamia Leidy, 1877
Family: Xiphodolamiidae Cappetta, 2012
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xiphodolamia morricei (1)
(Jordan & Beal, 1913)
Valid name: Hemipristis serra
Valid name: Hemipristis serra
Original description species: (Jordan & Beal, 1913)
Genus: Xiphodolamia Leidy, 1877
Family: Xiphodolamiidae Cappetta, 2012
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xiphodolamia serrata (4)
Adnet & Hosseinzadeh & Antunes & Balbino & Kozlov & Cappetta, 2009
Original description species: Adnet & Hosseinzadeh & Antunes & Balbino & Kozlov & Cappetta, 2009
Genus: Xiphodolamia Leidy, 1877
Family: Xiphodolamiidae Cappetta, 2012
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xiphodolamia sp. (6)

Genus: Xiphodolamia Leidy, 1877
Family: Xiphodolamiidae Cappetta, 2012
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xiphotrygon acutidens (3)
Cope, 1879
Valid name: Heliobatis radians
Valid name: Heliobatis radians
Original description species: Cope, 1879
Genus: Xiphotrygon Cope, 1879
Family: Dasyatidae Jordan & Gilbert, 1879
Order: Myliobatiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Xyphodolamia ensis (1)
Leidy, 1877
Valid name: Xiphodolamia ensis
Valid name: Xiphodolamia ensis
Original description species: Leidy, 1877
Genus: Xyphodolamia
Xystracanthus acinaciformis (1)
St. John & Worthen, 1875
Original description species: St. John & Worthen, 1875
Genus: Xystracanthus Leidy, 1859
Subclass: Elasmobranchii
Xystracanthus arcuatus (2)
Leidy, 1859
Original description species: Leidy, 1859
Genus: Xystracanthus Leidy, 1859
Subclass: Elasmobranchii
Xystracanthus konincki (1)
Lohest, 1878
Original description species: Lohest, 1878
Genus: Xystracanthus Leidy, 1859
Subclass: Elasmobranchii
Xystracanthus mirabilis (1)
St. John & Worthen, 1875
Valid name: Physonemus mirabilis
Valid name: Physonemus mirabilis
Original description species: St. John & Worthen, 1875
Genus: Xystracanthus Leidy, 1859
Subclass: Elasmobranchii
Xystrodus alatus (1)
De Koninck, 1878
Original description species: De Koninck, 1878
Genus: Xystrodus Plieninger In Schlönbach, 1860
Family: Hybodontidae Owen, 1846
Superfamily: Hybodontoidea
Order: Hybodontiformes
Cohort: Euselachii
Subclass: Elasmobranchii
Xystrodus angustus (1)
Agassiz, 1859
Valid name: Platyxystrodus striatus
Valid name: Platyxystrodus striatus
Original description species: Agassiz, 1859
Genus: Xystrodus Plieninger In Schlönbach, 1860
Family: Hybodontidae Owen, 1846
Superfamily: Hybodontoidea
Order: Hybodontiformes
Cohort: Euselachii
Subclass: Elasmobranchii
Xystrodus egertoni (2)
Davis, 1883
Original description species: Davis, 1883
Genus: Xystrodus Plieninger In Schlönbach, 1860
Family: Hybodontidae Owen, 1846
Superfamily: Hybodontoidea
Order: Hybodontiformes
Cohort: Euselachii
Subclass: Elasmobranchii
Xystrodus finitimus (1)
Plieninger, 1860
Original description species: Plieninger, 1860
Genus: Xystrodus Plieninger In Schlönbach, 1860
Family: Hybodontidae Owen, 1846
Superfamily: Hybodontoidea
Order: Hybodontiformes
Cohort: Euselachii
Subclass: Elasmobranchii
Xystrodus occidentalis (1)
St. John, 1870
Original description species: St. John, 1870
Genus: Xystrodus Plieninger In Schlönbach, 1860
Family: Hybodontidae Owen, 1846
Superfamily: Hybodontoidea
Order: Hybodontiformes
Cohort: Euselachii
Subclass: Elasmobranchii
Xystrodus pulchellus (1)
Davis, 1883
Original description species: Davis, 1883
Genus: Xystrodus Plieninger In Schlönbach, 1860
Family: Hybodontidae Owen, 1846
Superfamily: Hybodontoidea
Order: Hybodontiformes
Cohort: Euselachii
Subclass: Elasmobranchii
Xystrodus striatus (3)
M'Coy, 1855
Valid name: Platyxystrodus striatus
Valid name: Platyxystrodus striatus
Original description species: M'Coy, 1855
Genus: Xystrodus Plieninger In Schlönbach, 1860
Family: Hybodontidae Owen, 1846
Superfamily: Hybodontoidea
Order: Hybodontiformes
Cohort: Euselachii
Subclass: Elasmobranchii
Xystrodus verus (1)
St. John & Worthen, 1883
Original description species: St. John & Worthen, 1883
Genus: Xystrodus Plieninger In Schlönbach, 1860
Family: Hybodontidae Owen, 1846
Superfamily: Hybodontoidea
Order: Hybodontiformes
Cohort: Euselachii
Subclass: Elasmobranchii
Xystrogaleus cappettai (5)
Adnet, 2006
Original description species: Adnet, 2006
Genus: Xystrogaleus Adnet, 2006
Family: Triakidae Gray, 1851
Order: Carcharhiniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii