Fulmars: flight apparatus

Wing

The fulmar wing consist of 10 bones: humerus, ulna, radius, radiale, ulnare, carpometacarpus, alular digit, two bones of the major digit and one minor digit.
The arm part (3 bones): humerus and ulna/radius are nearly of the same length and are rather long to the hand wing. It has, unlike most other tubenoses, no sesamoid or spreader bone in the elbow. The tendons only form the supporting structure for the patagial fan in the outstreched wing, The hand wing (7 bones) consists of the radiale and ulnare: two small bones in the wrist, carpometacarpus and the digits.

Sternum, coracoid and furcula

The sternum of fulmarine petrels are, apart from differences in size, quite similar and of the 'gliding type': rather short, wide (square) but with a well developed keel. Compared with the ultimate gliders, the albatrosses, the fulmars have proprtionally larger flight muscles but can still not meet with the shearwaters. Fulmarine breastbones have four notches at the distal side of the sternum, forming a framework for a membrane that protects the intestinals. The Giant Petrel's breastbone is very much like those of the Mollymawks, shows no notches and has also pneumatic holes at the inside but not as many as in the albatrosses. The smaller fulmars don't have pneumatic holes i8n the breastbone.