Improved Claws not available for pathfinder summoner's eidolon

There's no such thing as an Improved Claws evolution. In the description of the Bite evolution there is text specifically saying that if the eidolon already has bite, then the bite damage increases. There is no similar text for any of the other natural attacks.

While reviewing this I notice that the Improved Bite should not be available to Bipeds anyway. Bite isn't an evolution that can be taken more than once so the only base forms that can improve the bite attack are ones that start with a bite attack. i.e. everything but bipeds.

Technically not an issue. The Improved Bite is not the same thing as Improved Damage. It's a special enhancement to the bite attack only available to eidolon base forms that start with a bite attack.

ah - so the actual issue is that PCGen has split "Bite" into 2 different implementations, and given the second a different name (not a name used in the game), but a name which is suspiciously plausibly close to a different evolution which applies to any natural attack including Bite.

Hmmm - recipe for confusion there!

Renaming it to Bite (1.5 x Str.) to avoid future confusion.