In Archaic Ascension, there are way more wild alpha dinos. These cannot be tamed and are considered mini bosses, and as such, drop decent loot. You'll also notice that these dinos (if configured properly depending on server) have a much higher wild level than your server level. These alphas are configured as if they evolved in the wild and leveled up their damage multiplier. It takes into account your wild max level, and post tame levels, and does some math to spawn them in at the same level as the highest possible player owned alpha.