The discovery of a new ancient flying reptile promises to answer questions—about the evolution of this species and others—that have been lingering since Charles Darwin's time.

The new 160-million-year-old pterosaur, named Darwinopterus in honor of the famed 19th-century naturalist, has emerged as an important middle specimen between early, long-tailed pterosaurs—also known as pterodactyls—and later short-tailed ones.

"We had always expected a gap-filler with typically intermediate features," David Unwin, of the University of Leicester's School of Museum Studies and a member of the research team that analyzed the fossils, said in a prepared statement. "Darwinopterus came as quite a shock to us." The new findings were published online today in the Proceedings of the Royal Society B.

The new animal, described from more than 20 specimens found in northeast China earlier this year, was not an average of primitive and advanced features as expected, but rather had some well-defined characteristics of each, including a long tail like older species and a head and neck like more recent ones. This discovery lends credence to the idea of rapid, "modular" evolution, in which large morphological parts of species undergo relatively fast changes via natural selection, rather than developing more slowly, bone by bone.