Erketu was a relatively large sauropod, with an estimated length of and a weight of . Its neck was estimated to be twice as long as its body, which may be a record for neck to body ratio. The exact ratio is unknown, because no
dorsal vertebrae of
E. ellisoni have been reported, although some hindlimb material suggests the approximate size of the body. The long neck of
Erketu is the result of the individual vertebrae being greatly elongated; it is unknown if the number of cervical vertebrae was increased.
Erketu is also diagnosed by bifurcate anterior cervical neural spines, another unusual trait for a titanosauriform. The preserved cervicals include the
atlas,
axis and C3 to C9, however, the sixth is missing, giving a total of eight preserved cervical vertebrae. The preserved sternum is rather thickened at some borders and shows a very deep lateral edge, it measures about long. The right hindlimb elements were nicely found in articulation and they resemble those of
Gobititan. The tibia is very straight, measuring in total length, it has slightly expanded ends and in comparison to that of
Opisthocoelicaudia, the anterior and distal expansions are not very developed. The fibula is longer than the tibia with a length of , however, it appears to be broken on the distal end of one of the
trochanters. ==Classification==