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Re: pteros have lift-off

Just so I understand, What is the number for the CG height at rest? And the number for the CG height above THAT number is 3.34 meters for Q northropi based on an isometrically scaled up Q sp? Is there a multiplier you use for determining height of apogee based on resting CG height?

Do you start at the zero point measuring acetabulum or glenoid height? And how many of these height units does your favorite pterosaur have to achieve in the first leap?

I use the cg, but glenoid works as a marker, too. For a 200kg Quetz northropi launching at 30 degrees from the horizontal, I get a cg elevation (or glenoid elevation) of 3.34 meters from the resting line (i.e. its a somewhat larger number taken from the beginning of the unload). Impressive, but hardly supernatural. And more than enough for clearance on the downstroke.

How fast do your calculations say a few particular pteros can run before they get to the femur breaking point?

Running speed to break point relationships are rather tricky, actually, but ballpark 6-7 m/s for a big azhdarchid, perhaps, assuming it could even run bipedally at all. Nyctosaurus comes in very wimpy, of course; probably under 4 m/s. But to be honest, I've mostly worried about bipedal leaping ability, because that's much more telling than running speed for several reasons (see below).

I can see your interest in the last hop after a running take-off. Or a bipedal hop vs. a quad hop. Absolutely.

If pteros ran at the speed of living lizards capable of bipedal locomotion, that would be a paltry 2.5 to 4 m/s or 5.7 to 8.8 miles/ hour. I looked through your paper and did not see a specific estimate for minimum flight speed. Is there a number we can compare?

David Peters