The Gait Debate:

In Ceratopsid dinosaurs, the forelimbs and hind limbs are nearly equal in length, identifying them as obligate quadrupeds. This premise is supported by their short, slender tail, which clearly did not act as a counterbalance to walk. Also, the presence of ossified tendons only in the hip region and a pelvis fused to the backbone along 10 sacral (lower back) vertebrae, rather than 4 or 5 that are typical of other dinosaurs, supports their quadrupedal posture (Lucas, 1994).

 

These characteristics suggest stability and power walking. The massive four-toed hind limbs are broad and hoofed, and the deep rib cage supported its massive shoulder girdle and forelimb.

 

As the title suggests, there has been much debate over the stance of the Ceratopsids. Many believe both the fore and hind limbs were positioned upright. Others suggest that the forelimbs were sprawling or semi-sprawling. One theory supporting the sprawling posture is derived from examination of the shape of the leg bones. When these bones are compared to those of modern lizards (sprawling), and to those of modern rhinoceros (upright), they more closely resemble those of the lizard and hence suggest a sprawling gait. Others believe that evidence found in Ceratopsian tracks indicates neither an upright nor a sprawling posture, but rather an intermediate and bow-legged stance. Unfortunately the evidence is inconclusive either way, and this debate remains unresolved (Lucas, 1994).

(Sims, 1994)

There is much debate surrounding the Ceratopsian gait. Figure portrays dorsal, lateral, and posterior views of the stance of Chasmosaurus

 

 

 

  

 

(Walters, 1996)

Hind foot structure of a ceratopsid

 

 

 

 

 

(Walters, 1996)

Forelimb gait debate. Left: sprawling/semi-sprawling gait. Right: upright gait.

 

 

 

 

(Sims, 1994)

When the humeri of a living Komodo dragon (middle), a living rhinoceros (right), and a Triceratops (left) are compared, it is easy to see that the ceratopsian most resembles the lizard humerous, corresponding to a sprawling/semi-sprawling gait (Lucas, 1994).