Young Echinoneus have been found with an Aristotle's lantern. Mortensen (1948, p. 74) regarded Echinoneus as a direct descendant of Pyrina, belonging to the holectypoids, while A. Agassiz (1872-1874, p. 332) points out the close structural resemblance between the young Echinolampas and Echinoneus.
Echinoneus is very similar to Micropetalon. The two genera can be distinguished by the orientation of the periproct. This appears to be oblique in the type species of Micropetalon, while in Echinoneus only the peristome is oblique, the periproct being longitudinally ovate.
J. Lambert & P. Thiery. 1909-1925. Essai de nomenclature raisonnee des echinides. Libraire Septime Ferriere, Chaumont, 607 pp., 15 pls.
T. Mortensen. 1948. A monograph of the Echinoidea: 4 (1): Holectypoida, Cassiduloida. Reitzel, Copenhagen, 363 pp., 14 pls.