[1][3] Members of this genus are collectively called spiny tree-rats.

The genus name Echimys, and also its synonym Echinomys,[2] derive from the two Ancient Greek words ἐχῖνος (ekhînos), meaning "hedgehog", and μῦς (mûs), meaning "mouse, rat".

These taxa are closely related to the genera Pattonomys and Toromys.

In turn, these five genera share phylogenetic affinities with a clade containing the bamboo rats Dactylomys, Olallamys, Kannabateomys together with Diplomys and Santamartamys.

[6] Isothrix Lonchothrix   (Tuft-tailed spiny tree-rat) Mesomys Pattonomys Toromys   (Giant tree-rat) Makalata Echimys Phyllomys Diplomys Santamartamys   (Red-crested tree-rat) Kannabateomys   (Atlantic bamboo rat) Dactylomys Olallamys