T. rex, bigger than ever

Photo taken at Universal Studios "Jurassic Park" 4/12/07 by Scott Kinmartin.

While Tyrannosaurus rex wasn't the largest of all meat-eating dinosaurs, it holds a special place in the hearts and minds of school children everywhere. No other animal symbolizes 'huge fearsome predator' like T. rex. It turns out that the kids may have been thinking too small. According to Jack Horner and his colleagues from the Museum of the Rockies, all the T. rex specimens we know about may have been still growing.

Earlier this month, Horner presented his findings at the Society of Vertebrate Paleontology. Upon cutting open a variety of bones in the museum's collection, he found evidence of blood vessels and osteocytes, hallmarks of bones that are still growing. This was true not only for bones previously labelled as 'juvenile' but also in bones thought to have come from adults.

To be clear, the 'adult' specimens may well have been sexually and behaviorally mature. There are species alive today that continue to grow throughout their lifetimes, and this may have been true of dinosaurs. Horner speculates that, had they lived, the larger T. rex specimens would have continued to grow thicker and bulkier, rather than longer or taller.

On the other hand, perhaps there are T. rex giants waiting to be discovered. Think about that, all you future paleontologists.