Most GMs don’t need a crib sheet for these animals. Hyenas mean gnolls, and vice versa. Encounter solved. But you can still find places for hyenas and hyaenodons in your world without their upright cousins.
On the so-called “Dark Continent” of Paliwar, certain people are considered something more and less than human. Due to the spiritual boundaries they regularly cross, blacksmiths, gravediggers, and oracles are all considered to have one foot in another world—especially the world of the dead—and often mark their foreheads with ash to represent their separate status. (Clerics and wizards are not considered of this caste, having rituals, vestments, and writing to protect them.) Druids and rangers with hyena or vulture companions are also among the ash-marked, their companions being scavengers who disturb the bodies of the dead.
The wild elves of Fel Sesh are not the vegetarian pacifists of the western forests. These elves wield sabers and ride brindle-furred hyaenodons into battle.
A magician (Advanced Player’s Guide 82) seeks to develop a more powerful hideous laughter spell to demonstrate his mastery of the bardic arts. A core component is the tongue of a dire hyena.
—Pathfinder Bestiary 179
I think I’ll put the majority of my comments in the main body of the posts from now on, in this fetching color. Of course, that means I have to go back and fix all my previous entries. Yikes…
Anyway, as far as I’m concerned those things in Peter Jackson’s The Two Towers weren’t Tolkein’s wargs; they were dire hyenas.
And apparently hyaenodons show up with Jenny Lewis in Primeval! I’m still on Season 3, so I need to get catch up…
Also, my take on Paliwar owes a very slight something to the Dogon cosmology as portrayed (problematically, according to some) in Conversations with Ogotemmêli. (I want to be sure to acknowledge both the debt and the controversy.)