Pa
- Pachycostasaurus Cruickshank, Martill & Noe, 1996 †
- Pachypleurosauria,
- Pachypleurosauridae Nopcsa, 1928 †
- Pachypleurosauroidea,
- Pachypleurosaurus,
- Pachystropheus,
- Paikasisaurus,
- Palacrodon,
- Palaeagama,
- Palaeoblanus,
- Palaeochamaeleo,
- Palaeoctonus,
- Palaeocursornis,
- Palaeolacerta
- Palaeophidae,
- Palaeosauriscus,
- Palaeosaurus cylindrodon,
- Palaeosaurus priscus,
- Palatodonta,
- Paleorhinus,
- Paleosuchus Gray, 1862
- Paliguana,
- Paliguanidae,
- Pallimnarchus †
- Pallisteria,
†Palvennia Druckenmiller et al. 2012
- †Palvennia hoybergeti Druckenmiller et al. 2012
Diapsida → Ichthyopterygia → Ophthalmosauridae → Ophthalmosaurinae
†Pamelaria Sen 2003
- †Pamelaria dolichotrachela Sen 2003
Reptilia → Diapsida → Prolacertiformes → Prolacertidae
- Pamelina,
- Paradipsosaurus,
- Parahupehsuchus
- Parahupehsuchus Chen et al., 2014 †
- Paralligaroridae †
- Paralligator †
- Paralonectes Nicholls & Brinkman, 1993 †
- Paramacellodidae,
- Paraplacodontidae Peyer & Kuhn-Schnyder, 1955 †
- Paraplacodontidae,
- Paraplacodus
- Paraplacodus Peyer, 1931 †
- Paraplacosauriops,
- Parapsicephalus
- Parapsicephalus Arthaber, 1918 †
- Pararcus,
- Parasaurillus,
- Parasauromalus,
- Parasuchidae
- Parasuchinae,
- Parasuchus Lydekker, 1885 †
- Parasuchus,
- Paratrisauropus,
- Pariguana,
- Paroedura,
- Parrishia,
- Parthanosaurus,
- Parvinatator Nicholls & Brickman, 1995 †
†Klada Parvipelvia Motani 1999
- †Hudsonelpidia McGowan 1995
- †Hudsonelpidiidae McGowan and Motani 2003
- †Macgowania Motani 1999
- †Macgowaniidae McGowan and Motani 2003
- †Neoichthyosauria Sander 2000
Diapsida → Ichthyopterygia → Hueneosauria → Longipinnati → Merriamosauria
- Parviraptor,
- Patricosaurus,
Pe
- Pedeticosaurus †
- Peipehsuchus †
- Peirosaurus †
- Pelagosaurus †
- Peloneustes Lydekker, 1889 †
- Pelycosimia,
- Perparvus,
- Pessosaurus Wiman, 1910 †
- Peteinosaurus
- Peteinosaurus Wild, 1978 †
- Petrolacosauridae †
- Petrolacosauridae,
- Petrolacosaurus †
- Petrolacosaurus,
- Petrosuchus †
Ph
- Phalarodon Merriam, 1910 †
- Phelsuma,
- Philydrosaurus,
- Phobetor Bakhurina, 1982 †
- Pholidosauridae †
- Pholidosaurus †
- Phosphatodraco Pereda Suberbiola, et al., 2003 †
- Phrynosoma,
- Phrynosomatidae,
- Phrynosomatinae,
- Phrynosomimini
- Phrynosomimus,
- Phygosaurus,
- Phyllodactylus,
- Phytosauria
- Phytosauria Meyer, 1861 †
- Phytosauridae Jaeger, 1828 †
- Phytosauridae,
- Phytosaurus,
Pi
- Picrodon,
- Pistosauria,
- Pistosauridae Baur, 1887-1890 †
- Pistosauridae,
- Pistosauroidea,
- Pistosaurus Meyer, 1839 †
- Pistosaurus,
Pl
- Placochelyida,
- Placochelyidae Jaekel, 1907 †
- Placochelyidae,
- Placochelys Jaekel, 1902 †
- Placochelys,
- Placodontia
- Placodontia Cope, 1871 †
- Placodontidae
- Placodontidae Cope, 1871 †
- Placodontiformes,
- Placodontoidea
- Placodus
- Placodus Agazzis, 1833 †
- Planocephalosaurus,
- Plataleorhynchus Howse & Milner, 1995 †
- Plateosaurus ornatus,
- Platydactylus,
- Platyognathidae †
- Platyognathidae,
- Platyognathus †
- Platyrhachis,
- Platysuchus †
- Plesiopleurodon Carpenter, 1996 †
- Plesiorhineura,
- Plesiosauria
- Plesiosauria Blainville, 1835 †
- Plesiosauridae Gray, 1825 †
- Plesiosauroidea,
- Plesiosaurus,
- Pleurodonta
- Pleurodontagama
- Pleurodontagaminae
- Pleurodontagamini
- Pleurosauri,
- Pleurosauridae,
- Pleurosaurus,
- Plica,
- Pliosauridae Seeley, 1874 †
- Pliosauridae,
- Pliosauroidea,
†Pliosaurus Owen, 1841
- †Pliosaurus andrewsi Tarlo 1960
- †Pliosaurus brachydeirus Owen, 1841
- †Pliosaurus brachyspondylus (Owen, 1840)
- †Pliosaurus carpenteri Benson et al., 2013
- †Pliosaurus funkei Knutsen et al., 2012[1]
- †Pliosaurus gamma Phillips 1871
- †Pliosaurus grandis Owen 1839
- †Pliosaurus grossouvrei Sauvage 1873
- †Pliosaurus irgisensis Novozhilov 1948
- †Pliosaurus kevani Benson et al., 2013
- †Pliosaurus macromerus Philips, 1871
- †Pliosaurus patagonicus Gasparini and O'Gorman 2014
- †Pliosaurus phosphaticus Stefano 1903
- †Pliosaurus portentificus Noè et al., 2004
- †Pliosaurus rossicus Novozhilov, 1948
- †Pliosaurus westburyensis Benson et al., 2013
Diapsida → Sauropterygia → Pliosauridae → Thalassophonea
-
Pliosaurus brachydeirus
-
Pliosaurus macromerus, ralje
-
Pliosaurus kevani
Po
†Porodica Podopterygidae Sharov 1971
- †Sharovipteryx Cowen 1981
Diapsida → Reptilia → Prolacertiformes
- Polrussia,
- Polychrotidae,
- Polychrus,
- Polycotylidae Williston, 1909 †
- Polycotylus Cope, 1869 †
- Polyglyphanodontia,
- Polyodontobaena
- Polyodontobaenidae,
- Polyptychodon Owen, 1841 †
- Polyptychodon,
- Pontopus,
- Poposauridae Nopsca, 1928 †
- Posphatosaurus †
- Postosuchus Chatterjee, 1985 †
Pr
- Pravusuchus,
- Preondactylus Wild, 1984 †
- Preondactylus,
- Prestosuchidae Romer, 1966 †
- Prestosuchus Huene, 1942 †
- Priscagama,
- Priscagaminae,
- Priscagamini
- Priscochelys,
- Pristichampsinae †
- Pristichampsus †
- Pristiguana,
- Procaiman †
- Prodiplocynodon †
†Prolacerta Parrington 1935
- †Prolacerta broomi Parrington 1935
Reptilia → Diapsida → Archosauromorpha → Prolacertiformes
†Porodica Prolacertidae Parrington 1935
- †Boreopricea Tatarinov 1978
- †Malutinisuchus Ochev 1986
- †Megacnemus von Huene 1954
- †Pamelaria Sen 2003
- †Prolacertoides Young 1973
- †Vritramimosaurus Sennikov 2005
Red Prolacertiformes Camp 1945
- †Cosesaurus Ellenberger and Villalta 1974
- †Jesairosaurus Jalil 1997
- †Podopterygidae Sharov 1971
- †Prolacerta Parrington 1935
- †Prolacertidae Parrington 1935
- †Rhombopholis Owen 1866
†Prolacertoides Young 1973
- †Prolacertoides jimusarensis Young 1973
Diapsida → Prolacertiformes → Prolacertidae
- Proneusticosaurus
- Protecovasaurus,
- Protenodontosaurus Pinna, 1990 †
- Protenodontosaurus,
- Proterochampsa †
- Proterochampsa,
- Proterochampsia,
- Proterochampsidae †
- Proterochampsidae,
- Proterosauria,
- Proterosuchia,
- Proterosuchidae Huene, 1914 †
- Proterosuchidae,
- Proterosuchus Broom, 1903 †
- Proterosuchus,
- Protoichthyosauridae Appleby, 1979 †
- Protoichthyosaurus Appleby, 1979 †
- Protome,
- Protorhineura,
Red †Protorosauria Huxley 1871
- Porodica †Prolacertidae
- Porodica †Protorosauridae
- Porodica †Tanystropheidae
- Podtaksa: †Akropus, †Drepanosauromorpha, †Trachelosaurus
Reptilia → Diapsida → Archosauromorpha
- Protorosauridae †
- Protorosauridae,
- Protorosaurus Meyer, 1830 †
- Protosuchia Mook, 1934 †
- Protosuchidae Brown, 1934 †
- Protosuchus Brown, 1934 †
Ps
- Psephochelys
- Psephoderma
- Psephoderma Meyer, 1858 †
- Psephosauriscus
- Psephosaurus
- Psephosaurus Brotzen, 1957 †
- Pseudhesperosuchus †
- Pseudolagosuchus,
- Pseudopalatinae
- Pseudopalatus,
- Pseudosaurillus,
- Pseudosuchia,
- Pseudotinosaurus
- Psilotrachelosaurus
Pt
- Pteraichnidae,
- Pteranodon Marsh, 1876 †
- Pteranodontoidea,
- Pterodactylidae Bonaparte, 1838 †
- Pterodactyloidea Plieninger, 1901 †
- Pterodactyloidea,
- Pterodactylus Cuvier, 1809 †
- Pterodaustriidae Bonaparte, 1971 †
- Pterodaustro Bonaparte, 1969 †
- Pterorhynchus Czerkas & Ji, 2002 †
- Pterosauria
- Pterosauria Kaup, 1834 †
- Pterosauromorpha
- Pterosuchia †
Pu
- Puntanipterus Bonaparte & Sanchez, 1974 †
- Purranisaurus †
Py
- Pygopodidae