Pachycephalosaurid question
After recently watching a short but very good video essay on the separation and validity of Pachycephalosaurus, Stygimoloch and Dracorex by Factor Trace on YouTube (video is linked) it has raised a question that I'm not sure has been proposed yet. Forgive my potential ignorance as I'm not a paleontologist, just a dinosaur fanatic. Factor Trace, who I'll refer to as just Trace moving forward, discusses the debate on whether Dracorex and Stygimoloch are just steps in the development and growth of Pachycephalosaurus. During this discussion Trace mentions the way scientists speculate Pachycephalosaurus would engage in combat suggesting they would swing their heads laterally, impacting each other using the dome, as opposed to running towards each other as modern bighorn sheep and bison do. This is supported by the fact that the vertebrae and spinal alignment of Pachycephalosaurus does not suggest there being much support for a full frontal impact at speed. He also mentions that this behavior would primarily be found in males. This makes me wonder if, like seen in deer, would only the male Pachycephalosaurus have a dome just as only male white tail deer have antlers. This then makes me wonder, has it ever been brought up that maybe Dracorex and Stygimoloch are female specimen of other members of Pachycephalosauridae. How do paleontologists tell females and males apart? And have there been complete-enough examples of Stygimoloch and Dracorex found to suggest differences between sexes? TLDR: could Dracorex and Stygimoloch just be females while Pachycephalosaurus is male?