Echimyinae

Echimyinae^[1] is a subfamily of rodents belonging to the spiny rats family Echimyidae.^[2] It contains 14 arboreal genera—all the members of the tribe Echimyini, plus Callistomys—a few terrestrial genera (Thrichomys, Hoplomys, and Proechimys), and a subaquatic genus (Myocastor).^[3]

Echimyinae
Ferreira's spiny tree-rat, Mesomys hispidus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Parvorder:	Caviomorpha
Superfamily:	Octodontoidea
Family:	Echimyidae
Subfamily:	Echimyinae Gray 1825 [1]
Tribes
Echimyini Myocastorini

Systematics

The taxonomic content of Echimyinae has been reshaped over time, because of two realizations. The first is a better understanding of the evolution of morphological characters, leading to the recognition that key character states long used to group genera into higher units were demonstrably homoplastic. The second came from the a phylogenetic analysis of molecular sequence data.^[3][4]

Comparison between molecular-based^[3] and traditional^[2] systematics for Echimyinae genera.

Genera	Molecular-based systematics	Traditional systematics
Echimys	Echimyini	Echimyinae
Phyllomys	Echimyini	Echimyinae
Makalata	Echimyini	Echimyinae
Pattonomys	Echimyini	Echimyinae
Toromys	Echimyini	Echimyinae
Diplomys	Echimyini	Echimyinae
Santamartamys	Echimyini	Echimyinae
Isothrix	Echimyini	Echimyinae
Dactylomys	Echimyini	Dactylomyinae
Olallamys	Echimyini	Dactylomyinae
Kannabateomys	Echimyini	Dactylomyinae
Lonchothrix	Echimyini	Eumysopinae
Mesomys	Echimyini	Eumysopinae
Callistomys	Myocastorini	Echimyinae
Myocastor	Myocastorini	Myocastoridae
Thrichomys	Myocastorini	Eumysopinae
Hoplomys	Myocastorini	Eumysopinae
Proechimys	Myocastorini	Eumysopinae

Phylogeny

The subfamily Echimyinae groups most of the spiny rat family's generic diversity into two tribes: Echimyini and Myocastorini.^[3]

Genus-level cladogram of the Echimyinae.

Echimyinae Myocastorini               Thrichomys (punaré)                       Callistomys (painted tree-rat)   Myocastor (nutria)             Hoplomys (armored rat)   Proechimys Echimyini              Isothrix   "Eumysopines"     Lonchothrix   (Tuft-tailed spiny tree-rat)   Mesomys                                           Pattonomys   Toromys   (Giant tree-rat)             Makalata   Echimys   Phyllomys   Diplomys   Santamartamys   (Red-crested tree-rat)   "Dactylomyines"     Kannabateomys   (Atlantic bamboo rat)             Dactylomys   Olallamys

The cladogram has been reconstructed from mitochondrial and nuclear DNA characters.[5][6][7][8][9][10][11][12][4]