For the difference in the number of epoccipitals they offered two additional explanations .
That the thin areas on Triceratops frills were muscle attachment sites was rejected by them because the bone at these points did not show the rugose surface typical for such an attachment .
For the difference in the number of epoccipitals Triceratops offered two additional explanations .
That the thin areas on Triceratops frills were muscle attachment sites was rejected by them because the bone at these points did not show the rugose surface typical for such an attachment .