1858
Graptolithus bifidus n. sp. — Hall, pp. 130
1865
Graptolithus bifidus J. Hall — Hall, pp. 73, fig. 1:16-18; 3:9-10
1947
Didymograptus bifidus — Ruedemann, pp. 327
1960
Didymograptus bifidus (Hall) — Obut, pp. 152, fig. V 2,2a
1962
Didymograptus bifidus J. Hall — Berry, pp. 294, fig. 1a-e, 2a-b
1982
Didymograptellus bifidus (Hall, 1865) — Cooper & Fortey, pp. 220
1988
Didymograptus (Didymograptellus) bifidus (J. Hall) — Williams et Stevens, pp. 41, fig. 12; 13:8-13
2006
Didymograptus (Didymograptellus) bifidus (J. Hall) — Jackson et Lenz, fig. 8 o-q; u-w
2010
Didymograptellus bifidus — Maletz, pp. 433, fig. 11A-E,G,H; 12A, E-H,J,K