Chenanisaurus is quite a large abelisaurid, measuring 7–8 m (23–26 ft), based on measurements of the holotype dentary.
It is rivalled in size only by  abelisaurids as Carnotaurus and Pycnonemosaurus.

Nicholas R. Longrich and colleagues, the describers of Chenanisaurus, identified distinctive features distinguishing the animal from other abelisaurid species.
The lower jaw is high, while the dentary is bent in side view.
The lateral groove and associated foramina are located high on the outer surface of the dentary.
The anterodorsal margin of the dentary is curved downward.
The symphysis of the lower jaws is heavily built while the leading edge is vertical in side view.
The front jaw points are wide in plan view, encountering each other at an obtuse angle.

The most striking feature of the mandible is the extreme height, especially when compared with the relatively short teeth.
This seems to indicate that the jaw is also very short, with a build even more extreme than seen in the related Carnotaurus.
This suggests the jaws were built to withstand a high bite force.
The jaw flexes forwardly downwards to terminate in a deep blunt point.
At the back there is a deep high furrow above it with a row of foramina that open towards the top in a series of vertical grooves.
The high position is a basal characteristic.
The outer lower side shows an ornamentation of pits and interweaved ridges.
The front interdental plates are very high but they quickly lower towards the rear of the jaw.
The tooth sockets are rectangular in upper view.
The jaw carries at least ten teeth.
These are relatively slender, but the front teeth have a D-shaped cross section with the convexity facing outward; the rear teeth are dagger-shaped and more flattened.
The cutting edges are convex and show up to thirteen denticles per five millimetres at the crown base, and up to eight denticles near the apex.
They have small blood grooves.
The enamel has an irregular structure without clear ornamentation.
Chenanisaurus is quite a large abelisaurid, measuring 7–8 m (23–26 ft), based on measurements of the holotype dentary. It is rivalled in size only by  abelisaurids as Carnotaurus and Pycnonemosaurus.
Nicholas R. Longrich and colleagues, the describers of Chenanisaurus, identified distinctive features distinguishing the animal from other abelisaurid species. The lower jaw is high, while the dentary is bent in side view. The lateral groove and associated foramina are located high on the outer surface of the dentary. The anterodorsal margin of the dentary is curved downward. The symphysis of the lower jaws is heavily built while the leading edge is vertical in side view. The front jaw points are wide in plan view, encountering each other at an obtuse angle.
The most striking feature of the mandible is the extreme height, especially when compared with the relatively short teeth. This seems to indicate that the jaw is also very short, with a build even more extreme than seen in the related Carnotaurus. This suggests the jaws were built to withstand a high bite force. The jaw flexes forwardly downwards to terminate in a deep blunt point. At the back there is a deep high furrow above it with a row of foramina that open towards the top in a series of vertical grooves. The high position is a basal characteristic. The outer lower side shows an ornamentation of pits and interweaved ridges. The front interdental plates are very high but they quickly lower towards the rear of the jaw. The tooth sockets are rectangular in upper view. The jaw carries at least ten teeth. These are relatively slender, but the front teeth have a D-shaped cross section with the convexity facing outward; the rear teeth are dagger-shaped and more flattened. The cutting edges are convex and show up to thirteen denticles per five millimetres at the crown base, and up to eight denticles near the apex. They have small blood grooves. The enamel has an irregular structure without clear ornamentation.
Chenanisaurus