On August 12 , 1990 , the most completeTyrannosaurus rexskeleton ever unwrap was excavate in the badlands of South Dakota by fossilist Peter Larson and Susan Hendrickson . The animal was dub “ Sue ” in honor of the latter scientist and , after alengthy sound battle , her stiff were buy for the hefty kernel of $ 8.4 million by the Chicago Field Museum . Today , she ’s easily become the humans ’s most far-famed dinosaur . But what if “ Sue ” was n’t actually a female ?
“ We ’d given theT. rexthat name and always referred to it as ' she ' or ' her ' , ” say Larson , “ But even at the situation , the great unwashed were asking me ' What if she ’s a male ? ' I ’d say that we could always point to that Johnny Cash song ' A son Named Sue . ' ”
Country classic notwithstanding , can paleontologists accurately make up one’s mind the sexual activity of a long - idle dinosaur ?
The short answer is yes … and no .
While Sue ’s gender remainsvery much in question , relatively recent research has shown that at least some dinosaur specimen may be sexed with reasonable sure thing by modern scientists . The riddle ’s solvent may very well consist in the bones of present - day dinos — also known as “ birds . "
produce eggs is a very taxing process for expectant avian mothers , as the calcium in their shells is biologically expensive to build . When testis start forge in the womb of a gravid bird , her dead body loose a heightened grade of oestrogen . This triggers the growth of what ’s known as “ medullary bone ” in spite of appearance of her vacuous stage and arm bone . The specialized medullary bone tissue provides much - need atomic number 20 for the growing eggshells and lingers until their windup , at which point it disappears .
In 2005 , paleontologists at North Carolina State University and Montana State University announced that they’ddiscovered medullary tissue paper within the tree branch bone of aT. rexspecimen , suggesting that the animal was A ) female and B-complex vitamin ) gravid at the time of its expiry .
The approach is hardly fool - proof : Only the bones of significant female dinosaur would show any planetary house of medullary tissue , rendering the proficiency useless for deduce the sex of the vast bulk of dinosaur skeleton . Nevertheless , the findings have excited a act of paleontologist , including one international squad which seek to deduce the link between grammatical gender and this tell - tale tissue in a group ofwell - preserved fossilized Bronx cheer this past February .
