Brachydios skull made using neoceratosaurs as reference. The reason for the texture is because his entire face is a keratin sheath. It might look like he’s got a big brain but really he’s just built to withstand slamming his face into the ground, but that isn’t to say brachy isn’t smarter than your average brute.
It also looks like he’s got big fenestra, but there actually isn’t that much room for muscles in there. The angle is deceiving. Brachy really doesn’t have that strong a bite in comparison to other brutes, not that he really needs it when he can beat the shit out of prey. Although his lack of a good bite are probably compensated by his finger claws and pounders, which can hypothetically cut pieces of meat and crush bone in place of jaws.
Brachy also has black teeth, but the reason for it isn’t known. It could be anything from symbiotic bacteria living there or a result of the compound his tongue secretes to excite his symbiotic slime mold (which isn’t a fungus believe it or not).
Brachy also has a blue shell, which is likely from biomineralization.