Pliosauridae Temporal range:Late Triassic -Late Cretaceous,228–89.3 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Liopleurodon ferox mounted skeleton, Museum of Paleontology,Tübingen
Cast of the primitive pliosaurAttenborosaurus conybeari (NHMUK R1339),Natural History Museum
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	†Sauropterygia
Order:	†Plesiosauria
Suborder:	†Pliosauroidea
Family:	†Pliosauridae Seeley,1874
Subgroups
†Anguanax †Arminisaurus †Attenborosaurus †Hauffiosaurus †Marmornectes †Monquirasaurus †Pachycostasaurus †Rhaeticosaurus †Thalassiodracon †Thalassophonea Benson &Druckenmiller,2013 †Gallardosaurus †Ischyrodon †Liopleurodon †Megalneusaurus †Simolestes †Peloneustes †Pliosaurus †Brachaucheninae Williston, 1925 †Acostasaurus †Brachauchenius †Kronosaurus †Lorrainosaurus †Luskhan †Makhaira †Megacephalosaurus †Polyptychodon †Sachicasaurus †Stenorhynchosaurus

Pliosauridae is afamily ofplesiosaurian marine reptiles from theLatest Triassic to the earlyLate Cretaceous (Rhaetian toTuronian stages). The family is more inclusive than the archetypal short-necked large headed species that are placed in the subcladeThalassophonea, with early,primitive forms resembling other plesiosaurs with long necks.

The largest thalassophonean pliosaurs reached 10–11 metres (33–36 ft), in length, with around a quarter of this length being the head. Thalassophonean pliosaurs represented the largest marine predators during their existence, spanning more than 80 million years.^[1]

Pliosaurs went extinct during the earlyLate Cretaceous and were subsequently replaced by themosasaurs.

Pliosauridae was formally named byHarry G. Seeley in 1874.^[2]

Pliosauridae is astem-based taxon defined in 2010 (and in earlier studies in a similar manner) as "all taxa more closely related toPliosaurus brachydeirus than toLeptocleidus superstes,Polycotylus latipinnis orMeyerasaurus victor".^[3] The family Brachauchenidae has been proposed to include pliosauroids which have very short necks and may includeBrachauchenius andKronosaurus.^[4] However, moderncladistic analyses found that this group is actually asubfamily of pliosaurids,^[5] and possibly even the "crown group" of Pliosauridae.^[6]

Within Pliosauridae, there is a more derived clade calledThalassophonea. Thalassophonea was erected byRoger Benson andPatrick Druckenmiller in2013. Thename is derived fromGreekthalassa (θάλασσα), "sea", andphoneus (φονεύς), "murderer". It is astem-based taxon defined as "all taxa more closely related toPliosaurus brachydeirus than toMarmornectes candrewi".^[7] It includes the short necked and large headed taxa that typify the family.^[8][9]

The followingcladogram follows an analysis by Benson & Druckenmiller (2014).^[7]

• Media related toPliosauridae at Wikimedia Commons

• Pliosaurids
• Hettangian first appearances
• Turonian extinctions
• Sauropterygian families

• Articles with short description
• Short description is different from Wikidata
• Articles with 'species' microformats
• Commons category link is on Wikidata