Microraptor zhaoianus, M. gui, M. hanqingi
Name: Microraptor zhaoianus, M. gui, M. hanqingi
Name Meaning: Small Thief
First Described: 2000
Described By: Xu et al.
Classification: Dinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves, Eumaniraptora, Dromaeosauroidea, Dromaeosauridae, Microraptoria
Microraptor is a fairly famous little dinosaur due to its clear four wings on its fossil. It is known from numerous (over 300 specimens), very well preserved fossils from Liaoning, China, in the Jiufotang Formation. Microraptor lived in the Aptian age of the Early Cretaceous, about 125 to 120 million years ago. Microraptor was distinctive at the time of its discovery for having long, pennaceous feathers, the kind that we typically associate only with birds - solidifying the link between birds and dinosaurs. It was about 1 meter long and only would come up to the calf of a 1.8 meter high person. It had a thick covering of feathers all over its body, with a fan on the end of the tail. Its fossilized melanosomes, or pigment cells, have been analyzed, and found to have black, glossy coloration and iridescence like modern starlings.
Microraptor, in having four limbs, and a tail fan, was probably able to glide between trees. In fact, the hind wings would have hindered its ability to run on the ground, and would have been confined to an arboreal environment. However, whether or not it could actually fly - meaning, power its own movement through the sky - is fairly controversial. It may have had too primitive of shoulder joints to flap; however it did have a shoulder girdle that could have allowed the wings to be positioned vertically, allowing upstroke of the wing. Wind tunnel experiments have been conducted that Microraptor could actually glide fairly well, regardless of its ability to power its own flight.
To glide, it has ben suggested that its hindlimbs and forelimbs were on different levels, such as on a biplane. It could have then glided by launching from a perch, swooping down, and then landing on another tree. Through this model, Microraptor could have potentially achieved powered flight, in addition to gliding. There are some who criticize this hypothesis, though these studies have been insufficient at best. Whether or not the biplane model is correct will require more testing and analysis. On the ground, Microraptor would have dragged its feathers behind him, and only by keeping the wings elevated could it have avoided damaging them. Thus it did not use its forelimbs to capture prey. It may have parachuted from trees to ambush prey on the ground from short distances. Thus, this creature was a mainly arboreal species, spending most o fits life in the trees.
This has profound implications for the evolution of flight in birds. It indicates that avian flight evolved from predominantly being powered by all four limbs to being only powered by the forelimbs. Studies of Archaeopteryx, modern birds, and dinosaurs with long primaries on their feet such as Pedopenna indicate that bird flight did undergo this shift. Microraptor has been preserved with remains of food in its stomach as well- specifically it could feed on mammals, lizards, and even tree-perching birds. It also could have eaten fish, due to the evidence of fish scales found in the abdomen. Thus, Microraptor was an opportunistic hunter, feeding on those things it could find in its habitat and glide down to catch. It may have been nocturnal, however its iridescent plumage indicates that this is unlikely.
Shout out goes to artisticthingem, the artist of the top Microraptor (and a general lover of four-winged dinosaurs, ad my friend)!