1. Paguridae Latreille 1802
2. Palaemonidae Rafinesque 1815
3. Palinuridae Latreille 1802
4. Pandalidae Haworth 1825
5. Pandanaceae Robert Brown
6. Pandaridae Milne Edwards 1840
7. Pandeidae Haeckel 1879
8. Panesthiidae
9. Pangasiidae Bleeker 1858
10. Papilionidae Latreille 1802
11. Paralepididae Bonaparte 1835
12. Paralichthyidae Chabanaud 1937
13. Parameciidae Dujardin 1840
14. Paramphistomidae Fischoeder 1901
15. Paranebaliidae Walker-Smith & Poore 2001
16. Paridae Vigors 1825
17. Paruterinidae Fuhrmann 1907
18. Pasiphaeidae Dana 1852
19. Passeridae Illiger 1811
20. Pectinariidae Quatrefages 1866
21. Pectinidae Rafinesque 1815
22. Pelagiidae Gegenbaur 1856
23. Pempheridae Bleeker 1859
24. Penaeidae Rafinesque 1815
25. Pennariidae McCrady 1859
26. Pennellidae Burmeister 1816
27. Pentacerotidae Bleeker 1859
28. Pentaphylacaceae Engler 1897
29. Pentatomidae Leach 1815
30. Percichthyidae Gosline 1966
31. Percidae Rafinesque 1815
32. Percophidae Swainson 1839
33. Peristediidae D.S. Jordan & C.H. Gilbert 1882
34. Perkinsidae Levine 1978
35. Perlodidae Klapálek 1909
36. Petromyzontidae A. Risso 1827
37. Petrosiidae van Soest 1980
38. Phacaceae J.I. Kim, et al. 2010
39. Phalacrocoracidae Reichenbach 1850
40. Phascolarctidae Owen 1839
41. Phasianidae Horsfield 1821
42. Phenacolepadidae Pilsbry 1895
43. Philichthyidae Vogt 1877
44. Philodinidae Ehrenberg 1838
45. Philometridae Baylis & Daubney 1926
46. Philomycidae Gray 1847
47. Philopteridae Burmeister 1838
48. Phliantidae Stebbing 1899
49. Phocidae Gray 1821
50. Pholididae Gill 1893
51. Phormosomatidae Mortensen 1934
52. Phyllodocidae Örsted 1843
53. Phyllognathopodidae Gurney 1932
54. Phyllophoridae Östergren 1907
55. Phylloscopidae Alström et al. 2006
56. Physalopteridae Leiper 1908
57. Physidae Fitzinger 1833
58. Picidae Vigors 1825
59. Pieridae Duponchel 1835
60. Pinaceae Lindley 1836
61. Pinguipedidae Günther 1860
62. Pinnidae Leach 1819
63. Pinnotheridae De Haan 1833
64. Pipidae J.E. Gray 1825
65. Piscicolidae Johnston 1865
66. Plagiorchiidae Liihe 1901
67. Plagusiidae Dana 1851
68. Planaxidae Gray 1850
69. Planoceridae Lang 1884
70. Planorbidae Rafinesque 1815
71. Plantaginaceae de Jussieu 1789
72. Plasmodiidae Mesnil 1903
73. Platidiidae Dall 1870
74. Platycephalidae T.N. Gill 1872
75. Platycnemididae Tillyard 1917
76. Pleidae Fieber 1817
77. Pleioplanidae Faubel 1983
78. Plesiopidae Günther 1861
79. Plethodontidae Gray 1850
80. Pleurobrachiidae Chun 1880
81. Pleuroceridae Fischer 1885
82. Pleuronectidae G. Cuvier 1816
83. Pleurotomariidae Swainson 1840
84. Pleustidae Buchholz 1874
85. Plotosidae Bleeker 1858
86. Pneumospiruridae Wu & Hu 1938
87. Poaceae (R. Brown) Barnhart 1895
88. Pocilloporidae Gray 1842
89. Podicipedidae Bonaparte 1831
90. Podocarpaceae Endlicher 1847
91. Podoceridae Leach 1814
92. Poecilasmatidae Annandale 1909
93. Poeciliidae Garman 1895
94. Poecilochaetidae Hannerz 1956
95. Poecilopsettidae Norman 1934
96. Pollicipedidae Leach 1817
97. Polycentropodidae Ulmer 1903
98. Polychelidae Wood-Mason 1875
99. Polyclinidae Milne Edwards 1841
100. Polygonaceae de Jussieu 1789
101. Polymorphidae Meyer 1931
102. Polynemidae Rafinesque 1815
103. Polynoidae Malmgren 1867
104. Polytrichaceae C.F. Schwägrichen
105. Pomacanthidae Jordan & Evermann 1898
106. Pomacentridae Bonaparte 1831
107. Pompilidae Fabricius 1798
108. Pomatiopsidae Stimpson 1865
109. Pontogeneiidae Stebbing 1906
110. Poritidae Gray 1842
111. Porpitidae Goldfuss 1818
112. Portunidae Rafinesque 1815
113. Potamidae Ortmann 1896
114. Potamididae H. Adams & A. Adams 1854
115. Potamogetonaceae Reichenbach 1823
116. Priacanthidae Günther 1859
117. Primulaceae Batsch ex Borkhausen 1797
118. Proboscidactylidae Hand & Hendrickson 1950
119. Procellariidae Leach 1820
120. Protocephalidae La Rue 1911
121. Protostrongylidae Leiper 1926
122. Psalidopodidae Wood-Mason 1892
123. Psammobiidae Fleming 1828
124. Psammocoridae Chevalier & Beauvais 1987
125. Pseudaliidae Railliet 1916
126. Pseudocerotidae Lang 1884
127. Pseudocrangonyctidae Holsinger 1989
128. Psittacidae Illiger 1811
129. Psychrolutidae T.N. Gill 1861
130. Pteriidae Gray 1847 (1820)
131. Pteromalidae Dalman 1820
132. Pteropodidae Gray 1821
133. Pterosagittidae Tokioka 1965
134. Ptilocodiidae Coward 1909
135. Pupinidae L. Pfeiffer 1853
136. Pycnonotidae G.R. Gray 1840
137. Pyramidellidae Gray 1840
138. Pyrgomatidae Gray 1825
139. Pyuridae Hartmeyer 1908