Microraptor

Microraptor is an extinct genus of small, paravian dinosaurs that lived around 125 to 120 million years ago. It is often referred as a ‘four-winged’ dromaeosaur. There are three described species of this genus, but studies have suggested that all of them belong to one species M. zhaoianus.

Pictures

Physical Description

Microraptor was a small, crow-sized species with a small skull and small beak. They had underrated or probably partially serrated teeth. Their upper arm bones were unusually long. Microraptor possessed four wings – one each on its forearms and hind legs. They had true flight feathers (both primary and secondary) like modern day birds. Microraptor is one of the few bird precursors to have wings and long flight feathers on their legs. Their body was covered with thick layer of feathers. Its color was glossy black possibly with a note of iridescence. The function of the hypothesized iridescence is not known, but it is believed that it had something to do with sexual display or communication. They also had a long and feathered tail.

Adaptation and Behavior

They probably lived on trees. Its narrow front wings were capable of gliding and flapping. Its hind wings were primarily used while taking a turn into the air. It is believed to be a clumsy runner as their wings were linked to the hind legs.

Since its forewings and hind wings were on different levels, an overlaid take-off would have been impossible. Paleontologist Sankar Chatterjee suggested that they had a phugoid style of gliding. Some researchers suggested that feathered dinosaurs could parachute from trees to the ground – possibly to ambush or attack their prey. In a 2007 study, Chatterjee and J. Templin stated that Microraptor’s combined wing surface was too narrow to parachute to the ground from a significant height without hurting it. But, they did not deny the possibility of parachuted short distances.

In the past, scientists have found mammalian bones, bird bones among its gut contents. In 2013, paleontologists said that they have found fish scales in the abdominal cavity of a specimen. It’s hunting behavior is not known. Anatomically, it was impossible for Microraptors to utilize its clawed forelimbs in catching its prey.

Based on its eye’s scleral ring, it was believed that Microraptor was nocturnal. But, some doubt this idea following the suggestion of Microraptor’s iridescent plumage.

Discovery and Naming

In 1999, Microraptor was first presented as part of a composite fossil named Archaeoraptor. In that sample, a Microraptor tail was added to the body of a Yanornis. A species name Archaeoraptor liaoningensis was given even before it was officially acknowledged as a recognized specimen. After it had been declared as fake, avian paleontologists tried to assign the name Archaeoraptor to that Microraptor part. However in the mean time, Xu Xing, one of the scientists who was part of the Arhcaeoraptor research team, had already found further remains and named it Microraptor zhaoianus. In 2010, it was stated that more than 300 undescribed skeletal remains attributable to Microraptor or probably its close relatives are present in several Chinese museums.

Interesting Facts

• Cryptovolans, earlier described as a four-winged dinosaur, is actually considered Microraptor species by many. Paleontologist Stephen Czerkas, while describing Cryptovolans pauli (which was earlier referred as different species), stated that their flying ability was better than Archaeopteryx.
• In 1915, naturalist William Beebe argued in favor of the existence of four-winged species at some point during the evolution of avians.
• Microraptor has been depicted in online games, toy lines and documentary films.