Bird skeletons delighted medieval anatomists because of their lightness and economy.(dinosaur factory) The bones of most flying birds are of a tubular-strut design. All the major limbs are cast in a thinwalled, hollow construction. Just so were the pterodactyl’s bones designed. Even the apparently massive upper arm bone (humerus) of the gigantic Texas pterodactyl had only an outer shell of very hard bone a few millimeters thick.
And just as avian bones achieve their greatest lightness by being filled not by marrow but by a core of air sacs connected to the lungs, likewise the pterodactyl’s bones are constructed to contain airsac liners. (life size dinosaur for sale)Though lung tissue itself is never preserved in fossils, the presence of air sacs can be detected from the characteristic pores in the bony walls which provided entrance for the air canals. Running one’s finger over the smooth-edged pore in the arm bone of a great aerial dragon is like feeling the fossil breath of the giant, now long gone. Through these pores surged the oxygen-rich air each time the stout basketwork of the ribcage drew the Mesozoic atmosphere through the dragon’s nostrils.
Arm power was wing power in pterodactyls, as it is in birds and bats.(animatronic dinosaur costume) The pterodactyl’s upper arm bones were short compared to birds’, but its forearm and wrist were longer a difference that must surely reflect an as yet undiscovered contrast in the mechanics of upstroke and downstroke. Strong fliers among today’s birds put greater stresses on the upper arm than on any other bony component. In these birds the humerus is the largest bone in the skeleton. (lifelike dinosaur for sale)And the distribution of stress in a pterodactyl’s skeleton can be discerned by scanning the patterns of girth in the bones-the humerus is always the thickest, usually twice the girth of the thigh. There’s no ambiguity here; pterodactyl’s evolutionary transformation had concentrated nearly all the body’s strength in the flight organ.