I have been working with this animation and ran into a bit of a snafu with the creature I call Toot (the vertically oriented Manta Ray type body plan creature). I use Maya 2017 and have tried several approaches including: Non-Linear Deformation- Bend (the animation curve did not transfer at all via fbx), Blend Shapes (marginal success but only displays a portion of the cycle: [https://skfb.ly/6o6ZM]) and FK/IK animation (Toot works but is choppy and distorted some of the fin shapes: [https://skfb.ly/6oqwI]). With the FK/IK animation, I resort to rekeying the joints that are moving because the more fluid IK does not seem to translate well via fbx (versions 2015-17) as well as the dae.fbx flavor. Incidentally, I sure wish the Nonlinear Bend would translate via Vertex animation because that is the most fluid of all. I'd be happy to share any of the models mentioned above in the hopes of getting this to work.
Many thanks for your time and any info you can provide.