Keichousaurus with two vertebral columns?

[Crazyhen]

This juvenile Keichousaurus should be a genuine one but I don't understand why it appears to have two separate vertebral columns.  It doesn't seem like the vertebral column is split into two due to fossilization process.  Any idea?

[TeethCollector]

More preparation using acid or mechanical may reveal more about this Keicho..

 

My hypothesis is..

I think the right vert is the original one, since it is more centered. Left one may be another Keichosaurus' vertebrae which accidently attached to this specimen, or something else which looks like a vertebrae.