1. Species Thyonidium drummondii (Thompson, 1840)
2. Species Thyonidium flavum Greeff, 1882
3. Species Thyonidium hyalinum (Forbes, 1841)
4. Species Thyonidium kurilensis (Levin, 1984)
5. Species Thyonidium productum (Ayres, 1852)
6. Species Thyonidium rigidum Sluiter, 1894
7. Species Thyonidium seguroensis (Deichmann, 1930)
8. Species Thyonidium tabulatum (Ohshima, 1915)
9. Species Thyonidium turriculacavum (Massin, 1987)
10. Species Thyonidium alexandri Fisher, 1907 accepted as Neothyonidium hawaiiense (Fisher, 1907)
11. Species Thyonidium anatium Perrier R., 1903 accepted as Pentadactyla longidentis (Hutton, 1872)
12. Species Thyonidium cebuensis Semper, 1867 accepted as Phyllophorus (Phyllothuria) cebuensis (Semper, 1867)
13. Species Thyonidium commune (Forbes, 1853) accepted as Thyonidium drummondii (Thompson, 1840) (misassigned date & synonym)
14. Species Thyonidium conchilegum Pourtalès, 1868 accepted as Benthophyllophorus conchilegum (Pourtalès, 1868)
15. Species Thyonidium diomedeae (Ohshima, 1915) accepted as Ekmania diomedeae (Ohshima, 1915)
16. Species Thyonidium Dübeni Norman, 1869 accepted as Thyonidium drummondii (Thompson, 1840) (synonym)
17. Species Thyonidium glabrum Ayres, 1851 accepted as Sclerodactyla briareus (Lesueur, 1824)
18. Species Thyonidium hawaiiense Fisher, 1907 accepted as Neothyonidium hawaiiense (Fisher, 1907)
19. Species Thyonidium japonicum von Marenzeller, 1882 accepted as Pentadactyla japonica (von Marenzeller, 1882)
20. Species Thyonidium magnum Ludwig, 1882 accepted as Massinium magnum (Ludwig, 1882)
21. Species Thyonidium musculosum Ayres, 1851 accepted as Sclerodactyla briareus (Lesueur, 1824)
22. Species Thyonidium occidentale Ludwig, 1875 accepted as Phyllophorus (Urodemella) occidentalis (Ludwig, 1875) accepted as Euthyonidiella occidentalis (Ludwig, 1875)
23. Species Thyonidium parvum Ludwig, 1881 accepted as Neothyonidium parvum (Ludwig, 1881)
24. Species Thyonidium pellucidum Düben & Koren, 1846, non Vahl, 1808 accepted as Ekmania barthii (Troschel, 1846) (synonym)
25. Species Thyonidium rugosum Théel, 1886 accepted as Pentadactyla longidentis (Hutton, 1872)
26. Species Thyonidium scabrum Sars M, 1868 accepted as Mesothuria intestinalis (Ascanius, 1805) (synonym)
27. Species Thyonidium schmeltzii Ludwig, 1875 accepted as Cladolabes schmeltzii (Ludwig, 1875)
28. Species Thyonidium asper Ayres, 1851 (uncertain > taxon inquirendum)
29. Species Thyonidium ehlersi Heller, 1868 (uncertain > nomen dubium)
30. Species Thyonidium elongatum Ayres, 1851 (uncertain > taxon inquirendum)

 The webpage text is licensed under a Creative Commons Attribution 4.0 License