He went down into a hole under some agave. Another ox beetle was in the hole, but I was unable to get a picture.
Order: Coleoptera
mandibulate mouthparts, tough bodies/hard exoskeleton, hard forewings called elytra, horn-like projections on the head
Order: Coleoptera
Family: Scarabaeidae. This is the rhino beetle. Heavy bodied, oval or elongate.