1. Tachinidae Bigot 1853
2. Taeniacanthidae C.B. Wilson 1911
3. Taeniidae Ludwig 1886
4. Talitridae Rafinesque 1815
5. Talpidae G. Fischer 1817
6. Tamaricaceae Link 1821
7. Taxaceae S.F. Gray 1822
8. Tegulidae Kuroda, Habe & Oyama 1971
9. Tellinidae Blainville 1814
10. Telorchiidae Looss 1899
11. Temnopleuridae A. Agassiz 1872
12. Tenebrionidae Latreille 1802
13. Tenthredinidae
14. Tephritidae Newman 1834
15. Terapontidae Richardson 1842
16. Terebellidae Johnston 1846
17. Terebrataliidae Cooper 1973
18. Terebratellidae King 1850
19. Terebratulidae Gray 1840
20. Terebridae Mörch 1852
21. Testudinellidae Harring 1913
22. Tetraclitidae Gruvel 1903
23. Tetradontidae Bonaparte 1832
24. Tetrameridae Travassos 1914
25. Tetraonchidae Bychowsky 1937
26. Tetrarogidae J.L.B. Smith 1949
27. Tetrastemmatidae
28. Tettigoniidae Krauss 1902
29. Theaceae D. Don 1825
30. Thecidellinidae Elliot 1958
31. Thelaziidae Skrjabin 1915
32. Thiaridae Gill 1871
33. Thripidae Stevens 1829
34. Thuidiaceae
35. Timaliidae Vigors & Horsfield 1827
36. Tingidae Laporte 1832
37. Tjalfiellidae Komai 1922
38. Torymidae Walker 1833
39. Toxopneustidae Troschel 1872
40. Trachichthyidae Bleeker 1859
41. Trachipteridae Swainson 1839
42. Transversotrematidae Witenberg 1944
43. Trapezidae Lamy 1920 (1895)
44. Triacanthidae Bleeker 1859
45. Triakidae J.E. Gray 1851
46. Trichinellidae Ward 1907
47. Trichiuridae Rafinesque 1810
48. Trichocephalidae Baird 1853
49. Trichocercidae Harring 1913
50. Trichodectidae Kellogg 1896
51. Trichodinidae Claus 1951
52. Trichodontidae Bleeker 1859
53. Trichonotidae Bleeker 1859
54. Trichosomoididae Hall 1916
55. Trichostrongylidae Leiper 1912
56. Trichotriidae Harring 1913
57. Trichuridae Ransom 1911
58. Triglidae A. Risso 1826
59. Tripedaliidae Conant 1897
60. Triphoridae Gray 1847
61. Tripterygiidae Whitley 1931
62. Trochamminidae Schwager 1877
63. Trochidae Rafinesque 1815
64. Trochomorphidae O.F. von Möllendorff 1890
65. Troglodytidae Swainson 1832
66. Troglotrematidae Odhner 1914
67. Tropiometridae A.H. Clark 1908
68. Trypanosomatidae Doflein 1901
69. Tubulariidae Fleming 1828
70. Turbinidae Rafinesque 1815
71. Turbinoliidae Milne Edwards & Haime 1848
72. Turdidae Rafinesque 1815
73. Typhaceae de Jussieu 1789