Yes, large Coelophysis ate smaller Coelophysis. For decades, the evidence of this was an accumulation of bones of a “small Coelophysis” inside the abdomen of a larger skeleton. However, close study of the bone accumulation revealed that the bones are actually those of a small crocodile that the large Coelophysis ate.
Nevertheless, in the Ghost Ranch bonebed of Coelophysis skleletons, many coprolites (fossil feces), some still inside the intestinal cavities of Coelophysis skeletons, contain the bones of small Coelophysis—teeth, vertebrae and foot bones. There are also coprolites outside the Coelophysis bodies that include such bones, and even what appears to be “vomit” containing small Coelophysis bones. This is conclusive evidence that Coelophysis was a cannibal.
Today, some living predatory reptiles, such as crocodiles, are cannibals. In particular, they eat their young during times of environmental stress or simply because the young are an easily acquired food source. Cannibalism in a voracious predator like Coelophysis thus should come as no surprise.