Where the evidence leads

Fossils show dinosaurs had more spine | Daniel James Devine

In recent decades, a dominant portion of paleontologists have taught that birds evolved from dinosaurs. The popular theory of bird origins has been bolstered by fossils showing filamentous patterns interpreted to be "protofeathers," or evolutionary precursors to modern feathers. But a controversial new study published in the Proceedings of the Royal Society B challenges this view.

The hubbub centers on a theropod called Sinosauropteryx, a turkey-sized dinosaur related to Tyrannosaurus rex. First discovered in 1994, Sinosauropteryx was hailed as an ancestor to birds after it was observed to sport a mane of fibrous structures along its spine—rudimentary feathers intended to keep the animal warm, as the theory went. But Alan Feduccia, a University of North Carolina professor and co-author of the Proceedings B paper, argues that a microscopic examination of the alleged "protofeather" fibers shows otherwise.