"Author's notes
Diictodon was created to find loopholes behind the "No terraforming" rule.
In Diictodon's case, his burrowing capability can be used to create a single structure.
A prime burrow.
Prime burrows are burrows where all Diictodon in a single tunnel network are linked. In other words, if all of the burrows are destroyed, then the Diictodon would "teleport" back to the prime burrow, same as all of your stuff.
From the prime burrow, you can craft a regular burrow and place it within a large radius, all burrows will be instantly connected to the prime burrow they were crafted in. Much similar to the generator, except the burrows cannot be placed on...

• Rock
  
• Underwater
  
• On structures(This includes crop plots AND saddle platforms)

And to make it clear, prime burrows and burrows work as a shared storage place. so you can access the same storage from far away places.
Two prime burrows CANNOT be placed in the same tunnel network, and as the dossier states, they will randomly find treasures like blueprints, trophies (like Argentavis talons and Rex arms), and many resources. Mostly however, they will dig up seeds. I should also mention that the burrows also work as an egg holder or feces holder. If Diictodon lays an egg or defecates, the feces and eggs will be within the inventory.

Wild Diictodon live in regular burrows, and yes they are passively tamed. Basically, you would open up the inventory of the tunnel and place a berry in the inventory. overtime, the diictodon will come out of its burrow and be very cautious, where you would carefully feed it.

NEXT ONE:
Saltasaurus :3"