Why Caviramus is a quadruped

Most of the time at least.
So, here is my official civilized response as to why even Caviramus was a quadrupedal pterosaur, and did not hop like a crow.

So, on the left, you see a Caviramus (no wing membranes for clarity) and on the right you see a crow (modeled after a random skeletal I forgot, I do NOT own the references used, the Caviramus skel belongs to Witton).

You can clearly see the crow has big feet located under it's centre of mass, along with much longer legs as well as more robust leg bones and a large pelvis to anchor the large muscles needed for bipedal locomotion.
Caviramus clearly lacks those features, but instead it has overbuilt wings with large manual digits for climbing and walking.
I just can't see why Caviramus would walk bipedally....except in Peters' universe.


(Don't start a war on this, I do this with my purest intentions, namely, science)