Study Says T-Rex Probably Wasn't A Feathery Beast After All

Some recent research indicated that the Tyrannosaurus rex — that is, the T-rex — may have had feathers, but a new study has dashed that speculation, finding that the massive, ancient beast in fact had scaly, reptilian-like skin. The idea of a feathery T-rex came from the discovery that some theropods had feathers, leading some to speculate that the massive Tyrannosaurus rex did, as well. Researchers have found, however, that the evolution of gigantism included the loss of these extensive feather coverings.

The information was recently published in a study in the journal Biology Letters, where researchers explain that it was the discovery of filamentous feathers on some of the larger tyrannosauroids that lead to speculation about feathers on the T-rex. Assuming it was true, the discovery would have been important for researchers studying the evolution of feathers — early feathers like the ones on tyrannosauroids were quite a bit different than the flight feathers now found on most birds.

To help determine whether the T-rex had these same early feathers, researchers looked at the skin impressions found with a T-rex skeleton and partial skull recovered in Montana. Data about these skin impressions was also compared with what is known about skin from related-but-different Late Cretaceous tyrannosauroids. Researchers followed the changes related to the skin over the course of evolution toward larger body sizes.

The team found that the T-rex and many other large similar dinosaurs in all likelihood had skin with a reptilian quality, as well as extensive scales across the tail, abdomen, and thorax. However, the researchers say there's strong indication that the scales differ from reptilian scales, instead being an evolution of the primitive feathers that covered earlier, smaller Tyrannosauroids.

Why the larger beasts evolved in such a way that resulted in feather loss is unknown at this time, however, there is speculation about it. One possible reason involved warmer climates, though this recent study dismisses the notion. Instead, they suggest that a combination of greater activity and larger size both required better heat-loss abilities and provided better heat retention, a combination that made feathers not only unnecessary, but also potentially harmful.

SOURCE: Biology Letters