Hands or feet

The hand of Iguanodon has become part of dinosaurian folklore for one obvious reason. The conical thumb-spike was originally identified as a rhinoceros-like horn on the nose of the Iguanodon (Figure 9) and was immortalized in the giant concrete models erected at London's Crystal Palace (Figure 2, Chapter 1). It was not until Dollo provided the first definitive reconstruction of Iguanodon in 1882 that it was proved to everyone's satisfaction that this bone was indeed a part of the dinosaur's hand. However, the hand (and the entire forelimb) of this dinosaur held a few more surprises.

The thumb, or first finger, comprises a large, conical, claw-bearing bone that sticks up at right angles to the rest of the hand and can be moved very little (Figure 21A). The second, third, and fourth fingers are very differently arranged: three long bones (metacarpals) form the palm of the hand and are bound tightly together by strong ligaments; the fingers are jointed to the ends of these metacarpals and are short, stubby, and end in flattened and blunt hooves. When these bones were manipulated, to see what their true range of movement was likely to be, it was found that the fingers splayed outwards (away from each other) and certainly could not flex to form a fist and perform simple grasping functions, as might have been expected. This distinctive arrangement looks similar to that seen in the feet of this animal: the three central toes of each foot are | similarly shaped and jointed, splay apart, and end in flattened ;

hooves. The fifth finger is different from all the others: it is quite o separate from the previous four and set at a wide angle from the ยง

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