User blog comment:Lord Loss/Monster Hunter Theory... Blog/@comment-4555457-20111219223557/@comment-3298463-20111219224533

It's not really that hard to explain from a evolutinoary standpoint, the Blos must have the same ancestors as the rest of wyverns. They may have kept their reinforced wings because they help them to move through the sand.

As for how they're able to dig, asides from the whole anatomy not being the most appropiate, the only remotely plausible explanation I can fin at the moment is that sand in MH behaves differently than the one we have on Earth. Maybe it's composed by the remains of really soft rocks, I dunno.