The duckbill’s tail corset evolved for an obvious mechanical purpose: to keep its backbone stiff and immobile from a point just behind its shoulders all the way down to the hindmost tail section. Even the most devout believers in swimming duckbills are forced to admit that this bony latticework would make for an unusually unsupple spine, the very reverse of what is necessary for swim-ming with smooth, horizontal undulations.dinosaur factory
The supposedly definitive monograph on duckbills came out in 1942. Its two authors (one was the senior professor of paleon-tology at Yale) had to engage in quite a twisted form of logic to explain away the problem of the duckbill’s stiff backside. They ad-mitted the bony system of rods must have evolved to maintain the backbone rigid for perambulations on land when the duckbills chose to walk about on terra firma. big size dinosaur. But perhaps, the authors argued, the tendons were a little loose so that a small degree of side-to-side movement was possible in the tail. But they ignored a critical problem. The duckbill’s ancestors had been land livers,life like dinosaur with mod-erately strong tail corsets, and the duckbills themselves increased the stiffness of the corset. The monographers of ’42 failed to ex-plain why duckbills would evolve in the wrong direction—why the duckbill family had stiffer, not more supple, tails than their ances-tors.