The holotype specimen represents a not fully-grown individual based on one unfused caudal vertebra, and therefore its adult size may be larger than the contemporary Neimongosaurus.
It was a small to medium-sized therizinosaur with an estimated length from 2.6 to 4 m (8.5 to 13.1 ft) and a weight of 91 to 400 kg (201 to 882 lb).

Erliansaurus was a bipedal herbivore.
For a therizinosauroid, its cervicals were rather short.
The preserved femur was very straight and had a very rounded femoral head; it measures 41.2 cm (412 mm).
The tibia was relatively elongated, measuring 37.3 cm (373 mm) long.
Its fibula had an uncommon form, with a very high front edge and a concave top.
The left arm is exceptionally preserved with almost every element intact, its hands bore enormous, strongly recurved and pointed claws of which the thumb claw was the largest, however, the carpal bones are missing.
The holotype specimen represents a not fully-grown individual based on one unfused caudal vertebra, and therefore its adult size may be larger than the contemporary Neimongosaurus. It was a small to medium-sized therizinosaur with an estimated length from 2.6 to 4 m (8.5 to 13.1 ft) and a weight of 91 to 400 kg (201 to 882 lb).
Erliansaurus was a bipedal herbivore. For a therizinosauroid, its cervicals were rather short. The preserved femur was very straight and had a very rounded femoral head; it measures 41.2 cm (412 mm). The tibia was relatively elongated, measuring 37.3 cm (373 mm) long. Its fibula had an uncommon form, with a very high front edge and a concave top. The left arm is exceptionally preserved with almost every element intact, its hands bore enormous, strongly recurved and pointed claws of which the thumb claw was the largest, however, the carpal bones are missing.
Erliansaurus