Kaibabvenator swiftae (2)
HODNETT, ELLIOTT, OLSON & WITTKE, 2012
HODNETT, ELLIOTT, OLSON & WITTKE, 2012
Original description species:
HODNETT, ELLIOTT, OLSON & WITTKE, 2012 
Genus: Kaibabvenator HODNETT, ELLIOTT, OLSON & WITTKE, 2012
Family: incert. fam.
Order: Ctenacanthiformes
Superorder: Cladodontomorphi
Subclass: Elasmobranchii

Genus: Kaibabvenator HODNETT, ELLIOTT, OLSON & WITTKE, 2012

Family: incert. fam.
Order: Ctenacanthiformes
Superorder: Cladodontomorphi
Subclass: Elasmobranchii
Kallodentis rhytistemma (1)
ENGELBRECHT, MÖRS, REGUERO & KRIWET, 2017
ENGELBRECHT, MÖRS, REGUERO & KRIWET, 2017
Original description species:
ENGELBRECHT, MÖRS, REGUERO & KRIWET, 2017 
Genus: Kallodentis ENGELBRECHT, MÖRS, REGUERO & KRIWET, 2017
Family: Triakidae GRAY, 1851
Order: Carcharhiniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Genus: Kallodentis ENGELBRECHT, MÖRS, REGUERO & KRIWET, 2017

Family: Triakidae GRAY, 1851

Order: Carcharhiniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Kannathalepis milleri (1)
MÄRSS & GAGNIER, 2001
MÄRSS & GAGNIER, 2001
Original description species:
MÄRSS & GAGNIER, 2001 
Genus: Kannathalepis MÄRSS & GAGNIER, 2001
Family: Kannathalepididae MÄRSS & GAGNIER, 2001
Order: Elegestolepidida

Genus: Kannathalepis MÄRSS & GAGNIER, 2001

Family: Kannathalepididae MÄRSS & GAGNIER, 2001

Order: Elegestolepidida
Kanodus robustus (1)
LEBEDEV, 2014
LEBEDEV, 2014
Original description species:
LEBEDEV, 2014 
Genus: Kanodus LEBEDEV, 2014
Family: Psephodontidae JAEKEL, 1898
Order: Cochliodontiformes
Superorder: Holocephalimorpha
Subclass: Holocephali

Genus: Kanodus LEBEDEV, 2014

Family: Psephodontidae JAEKEL, 1898
Order: Cochliodontiformes
Superorder: Holocephalimorpha
Subclass: Holocephali
Karaisurus demidkini (2)
KOZLOV IN ZHELEZKO & KOZLOV, 1999
KOZLOV IN ZHELEZKO & KOZLOV, 1999
Original description species:
KOZLOV IN ZHELEZKO & KOZLOV, 1999 
Genus: Karaisurus KOZLOV IN ZHELEZKO & KOZLOV, 1999
Family: Lamnidae BONAPARTE, 1835
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Genus: Karaisurus KOZLOV IN ZHELEZKO & KOZLOV, 1999

Family: Lamnidae BONAPARTE, 1835

Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Karksilepis parva (1)
MÄRSS, KLEESMENT & NIIT, 2008
MÄRSS, KLEESMENT & NIIT, 2008
Original description species:
MÄRSS, KLEESMENT & NIIT, 2008 
Genus: Karksilepis MÄRSS, KLEESMENT & NIIT, 2008
Family: incert. fam.
Order: incert. sedis

Genus: Karksilepis MÄRSS, KLEESMENT & NIIT, 2008

Family: incert. fam.
Order: incert. sedis
Karksiodus mirus (3)
IVANOV & MÄRSS, 2011
IVANOV & MÄRSS, 2011
Original description species:
IVANOV & MÄRSS, 2011 
Genus: Karksiodus IVANOV & MÄRSS, 2011
Family: incert. fam.
Order: incert. sedis
Subclass: Elasmobranchii

Genus: Karksiodus IVANOV & MÄRSS, 2011

Family: incert. fam.
Order: incert. sedis
Subclass: Elasmobranchii
Kathemacanthus rosulentus (2)
GAGNIER & WILSON, 1996
GAGNIER & WILSON, 1996
Original description species:
GAGNIER & WILSON, 1996 
Genus: Kathemacanthus GAGNIER & WILSON, 1996
Family: incert. fam.
Order: Climatiformes

Genus: Kathemacanthus GAGNIER & WILSON, 1996

Family: incert. fam.
Order: Climatiformes
Kawichthys moodiei (1)
PRADEL, TAFFOREAU, MAISEY & JANVIER, 2011
PRADEL, TAFFOREAU, MAISEY & JANVIER, 2011
Original description species:
PRADEL, TAFFOREAU, MAISEY & JANVIER, 2011 
Genus: Kawichthys PRADEL, TAFFOREAU, MAISEY & JANVIER, 2011
Family: incert. fam.
Order: Symmoriiformes
Superorder: Cladodontomorphi
Subclass: Elasmobranchii

Genus: Kawichthys PRADEL, TAFFOREAU, MAISEY & JANVIER, 2011

Family: incert. fam.
Order: Symmoriiformes
Superorder: Cladodontomorphi
Subclass: Elasmobranchii
Keasius parvus (77)
(LERICHE, 1908)
(LERICHE, 1908)
Synonyms:
Cetorhinus aff. parvus, Cetorhinus cf. parvus, Cetorhinus parvus, Praecetorhinus parvus, Selache parvus
Original description species: (LERICHE, 1908)
Genus: Keasius WELTON, 2013
Family: Cetorhinidae GILL, 1861
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Original description species: (LERICHE, 1908)

Genus: Keasius WELTON, 2013

Family: Cetorhinidae GILL, 1861

Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Keasius rhenanus (2)
REINECKE, VON DER HOCHT & DUFRAING, 2015
REINECKE, VON DER HOCHT & DUFRAING, 2015
Original description species:
REINECKE, VON DER HOCHT & DUFRAING, 2015 
Genus: Keasius WELTON, 2013
Family: Cetorhinidae GILL, 1861
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Genus: Keasius WELTON, 2013

Family: Cetorhinidae GILL, 1861

Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Keasius septemtrionalis (1)
REINECKE, VON DER HOCHT & DUFRAING, 2015
REINECKE, VON DER HOCHT & DUFRAING, 2015
Original description species:
REINECKE, VON DER HOCHT & DUFRAING, 2015 
Genus: Keasius WELTON, 2013
Family: Cetorhinidae GILL, 1861
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Genus: Keasius WELTON, 2013

Family: Cetorhinidae GILL, 1861

Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Keasius taylori (3)
WELTON, 2013
WELTON, 2013
Original description species:
WELTON, 2013 
Genus: Keasius WELTON, 2013
Family: Cetorhinidae GILL, 1861
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Genus: Keasius WELTON, 2013

Family: Cetorhinidae GILL, 1861

Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Kenolamna gunsoni (5)
(SIVERSON, 1996)
(SIVERSON, 1996)
Synonyms:
Cretolamna gunsoni
Original description species: (SIVERSON, 1996)
Genus: Kenolamna SIVERSON, LINDGREN, NEWBREY, CEDERSTRÖM & COOK, 2015
Family: Otodontidae GLICKMAN, 1964
Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Original description species: (SIVERSON, 1996)

Genus: Kenolamna SIVERSON, LINDGREN, NEWBREY, CEDERSTRÖM & COOK, 2015

Family: Otodontidae GLICKMAN, 1964

Order: Lamniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Khoratodus foreyi (3)
CUNY, SUTEETHORN, KAMHA & BUFFETAUT, 2008
CUNY, SUTEETHORN, KAMHA & BUFFETAUT, 2008
Original description species:
CUNY, SUTEETHORN, KAMHA & BUFFETAUT, 2008 
Genus: Khoratodus CUNY, SUTEETHORN, KAMHA & BUFFETAUT, 2008
Family: Thaiodontidae CUNY, SUTEETHORN, KAMHA & BUFFETAUT, 2008
Superfamily: Hybodontoidea
Order: Hybodontiformes
Cohort: Euselachii
Subclass: Elasmobranchii

Genus: Khoratodus CUNY, SUTEETHORN, KAMHA & BUFFETAUT, 2008

Family: Thaiodontidae CUNY, SUTEETHORN, KAMHA & BUFFETAUT, 2008

Superfamily: Hybodontoidea
Order: Hybodontiformes
Cohort: Euselachii
Subclass: Elasmobranchii
Khouribgaleus gomphorhiza (7)
(ARAMBOURG, 1952)
(ARAMBOURG, 1952)
Synonyms:
Galeorhinus aff. gomphorhiza, Galeorhinus gomphorhiza
Original description species: (ARAMBOURG, 1952)
Genus: Khouribgaleus NOUBHANI & CAPPETTA, 1997
Family: Triakidae GRAY, 1851
Order: Carcharhiniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Original description species: (ARAMBOURG, 1952)

Genus: Khouribgaleus NOUBHANI & CAPPETTA, 1997

Family: Triakidae GRAY, 1851

Order: Carcharhiniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Khuffia lenis (2)
KOOT, CUNY, TINTORI & TWITCHETT, 2013
KOOT, CUNY, TINTORI & TWITCHETT, 2013
Original description species:
KOOT, CUNY, TINTORI & TWITCHETT, 2013 
Genus: Khuffia KOOT, CUNY, TINTORI & TWITCHETT, 2013
Family: Sphenacanthidae MAISEY, 1982
Order: incert. sedis
Cohort: Euselachii
Subclass: Elasmobranchii

Genus: Khuffia KOOT, CUNY, TINTORI & TWITCHETT, 2013

Family: Sphenacanthidae MAISEY, 1982
Order: incert. sedis
Cohort: Euselachii
Subclass: Elasmobranchii
Khuffia prolixa (2)
KOOT, CUNY, TINTORI & TWITCHETT, 2013
KOOT, CUNY, TINTORI & TWITCHETT, 2013
Original description species:
KOOT, CUNY, TINTORI & TWITCHETT, 2013 
Genus: Khuffia KOOT, CUNY, TINTORI & TWITCHETT, 2013
Family: Sphenacanthidae MAISEY, 1982
Order: incert. sedis
Cohort: Euselachii
Subclass: Elasmobranchii

Genus: Khuffia KOOT, CUNY, TINTORI & TWITCHETT, 2013

Family: Sphenacanthidae MAISEY, 1982
Order: incert. sedis
Cohort: Euselachii
Subclass: Elasmobranchii
Kiestus texana (8)
(CAPPETTA & CASE, 1975)
(CAPPETTA & CASE, 1975)
Synonyms:
Ischyrhiza cf. texana, Ischyrhiza texana, Kiestus texanus, Ptychotrygon ritchiei
Original description species: (CAPPETTA & CASE, 1975)
Genus: Kiestus CAPPETTA & CASE, 1999
Family: Sclerorhynchidae CAPPETTA, 1974
Suborder: Sclerorhynchoidei
Order: Rajiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Original description species: (CAPPETTA & CASE, 1975)

Genus: Kiestus CAPPETTA & CASE, 1999

Family: Sclerorhynchidae CAPPETTA, 1974

Suborder: Sclerorhynchoidei
Order: Rajiformes
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Kimmerobatis etchesi (2)
UNDERWOOD & CLAESON, 2017
UNDERWOOD & CLAESON, 2017
Original description species:
UNDERWOOD & CLAESON, 2017 
Genus: Kimmerobatis UNDERWOOD & CLAESON, 2017
Family: Spathobatidae UNDERWOOD, 2006
Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Genus: Kimmerobatis UNDERWOOD & CLAESON, 2017

Family: Spathobatidae UNDERWOOD, 2006

Superorder: Batomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Knerialepis mashkovae (4)
(KARATAJUTE-TALIMAA, 1997)
(KARATAJUTE-TALIMAA, 1997)
Synonyms:
Kneria mashkovae, Knerialepis cf. mashkovae
Original description species: (KARATAJUTE-TALIMAA, 1997)
Genus: Knerialepis HANKE & KARATAJUTE-TALIMAA, 2002
Family: incert. fam.
Order: incert. sedis
Subclass: Elasmobranchii
Original description species: (KARATAJUTE-TALIMAA, 1997)
Genus: Knerialepis HANKE & KARATAJUTE-TALIMAA, 2002

Family: incert. fam.
Order: incert. sedis
Subclass: Elasmobranchii
Komoksodon kwutchakuth (1)
CAPPETTA, MORRISON & ADNET, 2019
CAPPETTA, MORRISON & ADNET, 2019
Original description species:
CAPPETTA, MORRISON & ADNET, 2019 
Genus: Komoksodon CAPPETTA, MORRISON & ADNET, 2019
Family: Komoksodontidae CAPPETTA, MORRISON & ADNET, 2019
Order: Hexanchiformes
Superorder: Squalomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Genus: Komoksodon CAPPETTA, MORRISON & ADNET, 2019

Family: Komoksodontidae CAPPETTA, MORRISON & ADNET, 2019

Order: Hexanchiformes
Superorder: Squalomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Kruckowlamna costarricana (1)
LAURITO MORA, 1999
LAURITO MORA, 1999
Original description species:
LAURITO MORA, 1999 
Genus: Kruckowlamna LAURITO MORA, 1999
Family: Carcharhinidae JORDAN & EVERMANN, 1896
Order: Carcharhiniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii

Genus: Kruckowlamna LAURITO MORA, 1999

Family: Carcharhinidae JORDAN & EVERMANN, 1896

Order: Carcharhiniformes
Superorder: Galeomorphii
Subcohort: Neoselachii
Cohort: Euselachii
Subclass: Elasmobranchii
Kungurodus obliquus (2)
(IVANOV, 2005)
(IVANOV, 2005)
Synonyms:
Cobelodus obliquus
Original description species: (IVANOV, 2005)
Genus: Kungurodus IVANOV, 2016
Family: incert. fam.
Order: Symmoriiformes
Superorder: Cladodontomorphi
Subclass: Elasmobranchii
Original description species: (IVANOV, 2005)

Genus: Kungurodus IVANOV, 2016

Family: incert. fam.
Order: Symmoriiformes
Superorder: Cladodontomorphi
Subclass: Elasmobranchii