Microraptor

Chapter • Meet the dinosaur

Overview

Microraptor was one of the smallest non-avian dinosaurs ever found, roughly the size of a crow or pigeon. It had a slender body, a small skull with tiny, forward-angled teeth, and a long stiffened tail ending in a fan of feathers. Its most striking feature is the plumage: long, asymmetrical flight feathers grew on both the arms and the legs, giving the animal four wing-like surfaces. Fossil melanosomes studied by Li and colleagues in 2012 indicate the feathers were black with an iridescent, glossy sheen similar to that of a modern starling or jackdaw. Exactly how Microraptor moved through the air is still debated. Most researchers picture it as a glider that climbed trees and sailed between trunks, though wind-tunnel experiments and computer models suggest it may also have managed short bursts of flapping flight. The feathers attached to the shins and toes would have made walking awkward, supporting the idea of a life spent mainly above ground. Like other dromaeosaurids it carried an enlarged, retractable claw on the second toe, although in Microraptor that claw was relatively modest. Gut contents preserved in several specimens give an unusually detailed picture of its diet. One individual contains the bones of an enantiornithine bird (O'Connor et al., 2011), another the remains of a small mammal (Larsson and Hone, 2010), a third fish scales and fish bones (Xing et al., 2013), and a fourth an entire lizard, Indrasaurus wangi, swallowed head first (O'Connor et al., 2019). Microraptor was clearly an opportunistic predator that took almost any small animal it could catch. Microraptor zhaoianus was described in 2000 by Xu Xing, Zhou Zhonghe and Wang Xiaolin, the species name honouring Chinese palaeontologist Zhao Xijin. The discovery has a dramatic backstory: the tail section of the notorious forged "Archaeoraptor" specimen turned out to belong to a Microraptor. The larger species Microraptor gui followed in 2003, and hundreds of specimens have since been excavated from the Jiufotang and Yixian formations of Liaoning Province in north-eastern China.

Chapter • Where it lived

Habitat

Microraptor lived about 125 to 120 million years ago, during the Early Cretaceous (Aptian), in what is now Liaoning Province in north-eastern China. Most fossils come from the Jiufotang Formation, with fewer from the older Yixian Formation, both part of the celebrated Jehol Biota. The landscape was a mosaic of lakes and wetlands fringed by conifer forest with ginkgoes, ferns, cycads and the earliest flowering plants, under a cool temperate climate punctuated by volcanic ash falls. Those ash falls buried animals so rapidly that feathers, gut contents and even colour-producing pigment structures survived.

Chapter • Wild behavior

Behavior & Ecology

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Chapter • Scientific place

Taxonomy