Microraptor is one of the world's most astonishing fossil discoveries: a tiny, feathered dinosaur possessing four, rather than two, wings, and the smallest creature in the dinosaur bestiary. On the following slides, you'll discover some essential Microraptor facts.01of 10
Microraptor Had Four, Rather Than Two, Wings
When it was discovered at the start of the new millennium, in China, Microraptor gave paleontologists a major shock: this birdlike dinosaur had wings on both its front and rear limbs. (All of the feathered "dino-birds" identified up to that time, such as Archaeopteryx, possessed only a single set of wings spanning their front limbs.) Needless to say, this has prompted some major reconsideration about how the dinosaurs of the Mesozoic Era evolved into birds!02of 10
Adult Microraptors Only Weighed Two or Three PoundsCorey Ford / Stocktrek Images / Getty Images
Microraptor shook up the world of paleontology in another way: for years, the late Jurassic Compsognathus was assumed to be the world's smallest dinosaur, only weighing about five pounds. At two or three pounds soaking wet, Microraptor has lowered the size bar considerably, even if some people still aren't willing to classify this creature as a true dinosaur (using the same reasoning by which they consider Archaeopteryx to be the first bird, rather than what it really is, a birdlike dinosaur).
Microraptor Lived 25 Million Years After Archaeopteryx
One of the most striking things about Microraptor is when it lived: the early Cretaceous period, about 130 to 125 million years ago, or a whopping 20 to 25 million years after the late Jurassic Archaeopteryx, the world's most famous proto-bird. This implies what many experts had already suspected, that dinosaurs evolved into birds more than once during the course of the Mesozoic Era (though clearly only one lineage survived into modern times, as determined by genetic sequencing and evolutionary cladistics).
Microraptor Is Known From Hundreds of Fossil Specimens
Hiroshi Nishimoto / Wikimedia Commons / CC BY 2.0
Not to overplay the contrast with Archaeopteryx, but this latter "dino-bird" has been reconstructed from about a dozen exquisitely preserved fossil specimens, all of them discovered in Germany's Solnhofen fossil beds. Microraptor, on the other hand, is known by hundreds of specimens excavated from the Liaoning fossil beds of China--meaning that not only is it the best-attested feathered dinosaur, but it's one of the best-attested dinosaurs of the entire Mesozoic Era!05of 10
One Species of Microraptor Had Black Feathers
Durbed / Wikimedia Commons / CC BY 3.0
When feathered dinosaurs fossilize, they sometimes leave behind traces of melanosomes, or pigment cells, which can be examined via electron microscopy. In 2012, Chinese researchers used this technique to determine that one Microraptor species possessed thick, black, layered feathers. What's more, these feathers were glossy and iridescent, a showy adaptation that may have been meant to impress the opposite sex during mating season (but had no particular impact on this dinosaur's ability to fly).06of 10
It's Unclear if Microraptor Was a Glider or an Active Flier
Since we can't observe it in the wild, it's difficult for modern researchers to tell if Microraptor was actually capable of flight--and, if it did fly, whether it actively flapped its wings or was content to glide short distances from tree to tree. We do know, however, that the feathered hind limbs of Microraptor would have made it an extremely clumsy runner, which lends support to the theory that this dino-bird was able to take to the air, probably by jumping off the high branches of trees (either to pursue prey or to evade predators).
One Microraptor Specimen Contains Mammalian Remains
What did Microraptor eat? To judge by the ongoing investigation of its hundreds of fossil specimens, pretty much everything that it happened across: the gut of one individual harbors the remains of a prehistoric mammal that looks very much like the contemporaneous Eomaia, while others have yielded remnants of birds, fish, and lizards. (By the way, the size and structure of Microraptor's eyes indicate that this dino-bird hunted at night, rather than during the day.)08of 10
Microraptor Was the Same Dinosaur as CryptovolansGetty Images / Handout / Getty Images
Around the time Microraptor was first coming to the world's attention, a maverick paleontologist decided that one fossil specimen deserved to be assigned to another genus, which he named Cryptovolans ("hidden wing"). However, as more and more Microraptor specimens were studied, it became increasingly clear that Cryptovolans was actually a Microraptor species--the vast majority of paleontologists now consider them to be the same dinosaur.09of 10
Microraptor Implies that Later Raptors May Have Been Secondarily Flightless
As far as paleontologists can tell, Microraptor was a true raptor, placing it in the same family as the much later Velociraptor and Deinonychus. What this means is that these famous raptors may have been secondarily flightless: that is, all the raptors of the later Cretaceous period evolved from flying ancestors, the same way ostriches evolved from flying birds! It's a dramatic scenario, but not all paleontologists are convinced, preferring to assign the four-winged Microraptor to a distant side branch of the raptor evolutionary tree.10of 10
Microraptor Was an Evolutionary Dead End
If you take a look in your backyard, you may notice that all the birds you see there have two, rather than four, wings. This simple observation leads inexorably to the conclusion that Microraptor was an evolutionary dead end: any four-winged birds that happened to evolve from this dinosaur (and for which we have as yet no fossil evidence) perished during the Mesozoic Era, and all modern birds evolved from feathered dinosaurs equipped with two wings rather than four wings.