I was struck the other day by a video of a cormorant 'flying' underwater in which it was shown to be clearly using both its wings and its feet to generate thrust and to manuever (braking, turning, etc). This is, of course, not news to anyone, but it made me wonder if M. gui may have used its hindlimb wings in much the same way while airbone. A "thrust producing kick" would have been useful to an animal with forelimb wings that on their own may have been too small for powered flight (an aspect ratio of between 4-5 based on my measurements from figure 1(c) in Xu et al--no idea what the wing loading was though). If the animal was using its forelimb wings to merely glide, a kick that produced some upward thrust would extend the time the animal could remain airborne. If, on the other hand, it was producing some thrust with its forelimb wings through some degree of flapping, appropriately t! im! ed kicks could have contributedto that overall lift and perhaps assisted in keeping the animal airborne for a much longer time.