| 1924 | Biradiolites semiannulosus sp. nov. -- TRECHMANN
, p. 401, pl.25, figs.6-7 |
| 1932 | Biradiolites semiannulosus Trechmann -- KÜHN
, p. 92 |
| 1956 | Thyrastylon semiannulosus (Trechmann) -- CHUBB
, p. 38 |
| 1956 | T. semiannulosus (Trechmann) -- CHUBB
, p. 8 |
| 1965 | Thyrastylon semiannulosus (Trechmann) -- COATES
, p. 32 |
| 1971 | Thrastylon semiannulosus (Trechmann) -- CHUBB
, p. 191, pl.39, fig.4 |
| 1981 | Thyrastylon semiannulosus Trechmann -- S+NCHEZ
, p. 210 |
| 1989 | Thyrastylon semiannulosas [sic] (Trechmann) -- DAVIS-STRICKLAND
, p. 31 |
| 1993 | T. semiannulosus -- DAVIS-STRICKLAND & DONOVAN
, tab.1 |