Ryan C. McKellar/Royal Saskatchewan Museum
The golden chunk of amber is 99 million years old. Inside sits something extraordinary. It’s a tiny dinosaur tail — with pristinely preserved feathers.
The tail is about the length of a matchstick, a bit under 37 millimeters (1.5 inches). It curves through the fossilized resin known as amber. Within, eight full sections of vertebrae are present. Mummified skin can be seen shrink-wrapped to bone. A full-bodied bush of long filaments sprouts along the tail’s length. A team led by Lida Xing of the China University of Geosciences in Beijing, China, described the finding December 8 in Current Biology.
It’s “an astonishing fossil,” they write. Feathers from this time period, the Cretaceous, have been found trapped in amber before. The new find, however, is the first with clearly identifiable bits of dinosaur included. The tail bones of the new fossil gave Xing’s team a clue to the dino’s identity. It may have been a young coelurosaur (see-LOOR-uh-soar). It would have looked something like a miniature Tyrannosaurus rex.
Dinosaur feathers pressed flat into rock don’t always provide much information about structure. Those preserved in amber can offer more, the authors point out. In amber, “the finest details of feathers are visible in three dimensions,” the researchers write.
The little dino’s feathers lack a well-developed rachis. This is the narrow shaft that runs down the middle of some feathers, including those used by modern birds for flight. Instead, the dino’s feathers may have been ornamental, the authors say. Under a microscope, they appeared chestnut brown on top, and nearly white below.
amber Fossilized tree resin (not sap). Researchers think most of this gemstone likely comes from conifers, or evergreen trees that bear cones.
biology The study of living things. The scientists who study them are known as biologists.
birds Warm-blooded animals with wings that first showed up during the time of the dinosaurs. Birds are jacketed in feathers and produce young from the eggs they deposit in some sort of nest. Most birds fly, but throughout history there have been the occasional species that don’t.
coelurosaur A small, slender, bipedal, carnivorous dinosaur with long forelimbs. Scientists believe birds evolved from coelurosaurs.
colleague Someone who works with another; a co-worker or team member.
dinosaur A term that means terrible lizard. These ancient reptiles lived from about 250 million years ago to roughly 65 million years ago. All descended from egg-laying reptiles known as archosaurs. Their descendants eventually split into two lines. They are distinguished by their hips. The lizard-hipped line became saurichians, such as two-footed theropods like T. rex and the lumbering four-footed Apatosaurus (once known as brontosaurus). A second line of so-called bird-hipped, or ornithischian dinosaurs, led to a widely differing group of animals that included the stegosaurs and duckbilled dinosaurs.
fossil Any preserved remains or traces of ancient life. There are many different types of fossils: The bones and other body parts of dinosaurs are called “body fossils.” Things like footprints are called “trace fossils.” Even specimens of dinosaur poop are fossils. The process of forming fossils is called fossilization.
geoscience Any of a number of sciences, like geology or atmospheric science, concerned with better understanding the planet. People who work in this field are known as geoscientists.
resin A sticky, sometimes aromatic substance, often secreted by plants. It may also be the viscous starting ingredient for some plastics that will harden when heated or treated with light.
Tyrannosaurus rex A top-predator dinosaur that roamed Earth during the late Cretaceous period. Adults could be 12 meters (40 feet) long.