I just got into a fight with a Frost Dragon. There was a giant and two mammoths who also joined the battle.

I blasted the dragon with as many fireballs as I could, but when I ran out of Magicka when the large beast had almost been defeated, the mammoth took the final blow and defeated the hellish creature.

When I approached the dragon, expecting to receive my dragon soul as a reward, I got nothing but a pile of dragon bones and scales. There was no dragon soul to be found.

Am I encountering a glitch, or do you have to finish the dragon off yourself to obtain the dragon soul?

It's a glitch.

Damn.... Ok, thanks.

Obviously the Mammoth is now the current Dragonborn.

That made me laugh. Nice one.

The Day Before- Mammoth: "Maybe I'm the Dragonborn but I just don't know it".

Mammoth?? 7000 steps?!?!

Who deals the killing blow is irrelevant, it's just that sometimes, the Dragon's soul doesn't release. http://images.wikia.com/gyropedia/images/9/91/1327974741374.png

You can't receive a soul again from a respawned dragon until that dragon levels up.

hahahahahahhahahhahaaha thats too funny

If the dragon was just a general one randomly spawned by the game engine, it should have given you a soul to collect as long as you made at least one strike or hit on the beast. However if the dragon is associated with a landmark / wordwall location, and you already made a dragon kill there, and took the word, then it's respawn at a later timepoint in the game will not give you a soul. No double dipping (spamming) on souls by repeatedly going to a known dragon lair!

It's entirely possible to think you killed a random dragon, when it could have been a landmarked dragon that was just out ranging around.....When I don't receive a soul, I usually open up the map ( I play w/o HUD) and check if I'm near a landmarked location. I'll usually journey up to the location, and collect the loot in the large chest there. I've yet to make the trip, and find out that the "deadbeat" soul less dragon wasn't the one I suspected it was.

A few more interesting things about dragon souls.

If you make a critical strike on a dragon and it crashes on the other side of a mountain range becoming difficult to access, or perhaps you've made the kill but the corpse rolls all the way out of sight, and you can't locate it, the game seems to remember where the body is, even after it ceases to generate the graphic. I've had a few locations where I was just walking or climbing the hill sides and suddenly a dragon soul is collected out of seemingly nowhere. Then i remembered , yeah this is near where I made a kill, but didn't care to walk all the way around the mountiains to go collect.

Less rewarding, is the fact that you can collect a dragon soul, even if your PC is lying dead on the ground. I once got involved with a melee where Jordis and Rexx were simultaneously ambushed by an ancient dragon and a swarm of Forsworn natives not far from the gold mine east of Markarth. About level 40 at the time, and probably the most epic battle I'd been in. As the dragon went into a death dive, I was one-shotted by a Forsworn mage, and crumpled up against the rock wall. Jordis continued to fight, and cleared up the Forsworn, after recovering from a beatdown. I'm still to myself and waiting for the game to reload, but the game never does, I'm just lying there, and suddenly the soul collection animation kicks in, along with the fanfare music.

That Mammoth is the second dragonborn of the game. Thus, it took the soul before you did.