1858
Graptolithus bifidus n. sp. — Hall, pp. 130
1865
Didymograptus bifidus — Hall, pp. 73, fig. 1:16-18; 3:9-10
1901
Didymograptus bifidus — Elles and Wood, pp. 42, fig. 4:1a-f
1934
Didymograptus bifidus — Hsü, pp. 39, fig. 2:10a-c
1937
Didymograptus bifidus — Ekström, pp. 26, fig. 2:9-15
1947
Didymograptus bifidus — Ruedemann, pp. 327, fig. 54:11-16
1960
Didymograptus bifidus (Hall) — Obut, pp. 152, fig. 5:2-2a
1962
Didymograptus bifidus (J. Hall) — Berry, pp. 294, fig. 1a-e, 2a-b
1970
Didymograptus bifidus (J. Hall, 1865) — Skevington, pp. 426, fig. 9a
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 (J. Hall 1865) — Maletz, fig. 11A-E,G,H; 12A, E-H,J,K