How does the Shaman True Spirit Ability for Nature Spirits apply to a Lvl 17 Spirit Summoner

Question

I was looking through Summoner archetypes to decide what my end-goal for my next Pathfinder character would be build-wise, when i stumbled across the Spirit Summoner. I found the concept of my summoner having shaman abilities fascinating. However, there was one thing that was a bit unclear with how everything was worded under the Nature Spirit (which i have set my heart on considering the hexes). I noticed that under the True Ability that I would get if I made it to Lvl 17, my "Spirit Animal" takes the form of an Animal Companion, retaining its abilities and Int score and gaining the animal's abilities and other scores. However, nowhere in the archetype description does it say that Spirit Summoners get Spirit Animals.

So my question is when I get to Lvl 17, does my character gain an Animal Companion, have his Eidolon become an Animal Companion with its evolution pool, or ignore this ability?

Answer 1

For a straight lv17 Spirit Summoner, this ability does nothing.

Spirit Summoner says this of the Spirit you are granted:

A spirit summoner forms a mystical bond with one spirit from the shaman class. He gains the spirit ability of that spirit and uses his summoner level as his shaman level for determining its effects...
At 9th level, the summoner gains the abilities listed in the greater version of his selected spirit.
At 17th level, the summoner gains the abilities listed for the true version of his selected spirit.

The nature spirit grants you the following abilities.

Storm Burst (Su): As a standard action, the shaman causes a small storm of swirling wind and rain to form around one creature within 30 feet. This storm causes the target to treat all foes as if they had concealment, suffering a 20% miss chance for 1 round plus 1 round for every 4 shaman levels she possesses. The shaman can use this ability a number of times per day equal to 3 + her Charisma modifier. At 11th level, any weapon she wields is treated as a thundering weapon.

Spirit of Nature (Su): Whenever the shaman is reduced to below 0 hit points, she automatically stabilizes and gains fast healing 1 for 1d4 rounds. At 15th level, this increases to fast healing 3.

Companion Animal (Su): The shaman’s spirit animal takes the form of an animal companion of her choice, using her shaman level as her effective druid level. [ ... more stuff about how this works... ]

None of this gives you access to the Spirit Animal class feature of the Shaman, and as such you do not have, unless you've multi classes into Shaman, a spirit animal for your nature spirit ability to transform into a real animal.