type Sardinidion perplexum Wunderlich, 1995; gender neuter

In synonymy:
Sardinidion perplexum Wunderlich, 1995 = Sardinidion blackwalli (O. Pickard-Cambridge, 1871) (Wunderlich, 2008b: 394).

Theridion blackwallii O. Pickard-Cambridge, 1871a: 419, pl. 55, f. 16 (Dm).
Euryopis blackwalli O. Pickard-Cambridge, 1874d: 324.
Theridion hasseltii Thorell, 1875a: 92 (Dmf).
Theridion hasseltii Thorell, 1875c: 51 (Dmf).
Theridion blackwalli L. Koch, 1877b: 183, f. 3-4 (Df).
Theridion blackwalli Bösenberg, 1902: 104, pl. 9, f. 129 (mf).
Theridion blackwalli Wiehle, 1937: 176, f. 154-159 (mf).
Allotheridion blackwalli Archer, 1950: 20 (Tmf from Theridion).
Theridion blackwalli Locket & Millidge, 1953: 73, f. 48A-B, 49A (mf).
Theridion blackwalli Miller, 1971: 193, pl. XXXIV, f. 14-15 (mf).
Theridion blackwalli Roberts, 1985: 184, f. 83e (mf).
Theridion blackwalli Heimer & Nentwig, 1991: 302, f. 811 (mf).
Theridion blackwalli Roberts, 1995: 286, f. (mf).
Sardinidion perplexum Wunderlich, 1995u: 688, f. 1-7 (Dm) [urn:lsid:nmbe.ch:spidersp:008006].
Theridion blackwalli Roberts, 1998: 301, f. (mf).
Sardinidion perplexum Trotta, 2005: 175, f. 455 (m).
Theridion blackwalli Türkes & Mergen, 2007: 117, f. 4 (f).
Sardinidion blackwalli Wunderlich, 2008b: 394, f. 570-578 (Tmf from Theridion, S).
Theridion blackwalli Le Peru, 2011: 474, f. 807 (mf).
Sardinidion blackwalli Crespo et al., 2018: 384, f. 15a-d (mf).
Sardinidion blackwalli Vanuytven, 2021: 46, 251, f. A.35b, B.269a-b, B.270 (m).