[4] Originally misclassified as "modern", the fossil received little attention after its publication in the 19th century as it was compared to Engis 1 - the almost perfectly preserved skull of an adult Homo sapiens.

In 1758, Carl Linnaeus had published the 10th edition of his work Systema Naturae in which Homo sapiens as a species name was introduced to the public, yet without a thorough diagnosis and without a precise description of the species-specific characteristics.

[6] Even Thomas Henry Huxley, a supporter of Darwin's theory of evolution, saw in the 1863 findings of the Engis cave a "man of low degree of civilization" and also interpreted the Neandertal 1 fossils of the Kleine Feldhofer Grotte unearthed in 1856 as belonging within the range of variations of modern man.

"[12] The findings are preserved at the Collections de Paléontologie Animale et Humaine of the University of Liège.

[13] The evolutionary origin of an ulna (forearm bone) fragment called Engis 4 discovered in 1872 is unclear; it has to date not been associated with a specific taxon.