Wednesday, December 13, 2006
From BBC News (UK): Mammals took to the skies at least 70 million years earlier than previously thought, scientists say.
A fossil uncovered in China suggests mammals were trying out flight at about the same time - or even earlier - than birds, the team reports in Nature.
The researchers said the squirrel-sized animal, which lived at least 125 million years ago, used a fur-covered skin membrane to glide through the air.
The creature was so unusual, they said, it belonged to a new order of mammals.
The US-Chinese team said Volaticotherium antiquus, which means 'ancient gliding beast', belonged to a now extinct ancestral line and was not related to modern day flying mammals, such as bats or flying marsupials.
Continued at "Earliest flying mammal discovered"
Based on the jounal Nature paper:
"A Mesozoic gliding mammal from northeastern China"
by Jin Meng*, Yaoming Hu, Yuanqing Wang, Xiaolin Wang and Chuankui Li
Gliding flight has independently evolved many times in vertebrates. Direct evidence of gliding is rare in fossil records and is unknown in mammals from the Mesozoic era**. Here we report a new Mesozoic mammal from Inner Mongolia, China, that represents a previously unknown group characterized by a highly specialized insectivorous dentition and a sizable patagium (flying membrane) for gliding flight. The patagium is covered with dense hair and supported by an elongated tail and limbs; the latter also bear many features adapted for arboreal life. This discovery extends the earliest record of gliding flight for mammals to at least 70 million years earlier in geological history, and demonstrates that early mammals were diverse in their locomotor strategies and lifestyles; they had experimented with an aerial habit at about the same time as, if not earlier than, when birds endeavoured to exploit the sky.
*From Jin Meng's homepage:
"I am interested in morphology, systematics and evolution of mammals in general and early mammals in particular. My past research concerned several mammal groups such as didymoconids, multituberculates, and gliriforms (rodents, lagomorphs and their early kin). Current research focuses on higher-level phylogeny of Glires (Rodentia + Lagomorpha): their morphology, relationships, distributions, function and evolution. In addition to teeth, I have been working on cranium, ear region and enamel microstructure of teeth as sources of data to address phylogenic and evolutionary issues of those taxa." [More]
**Info on the Mesozoic (comprising the Triassic, Jurassic, and Cretaceous):
The Mesozoic Era is one of three geologic eras of the Phanerozoic eon. The division of time into eras dates back to Giovanni Arduino, in the 18th century, although his original name for the era now called the 'Mesozoic' was 'Secondary' (making the modern era the 'Tertiary'). Lying between the Paleozoic and the Cenozoic, Mesozoic means 'middle animals', derived from Greek prefix meso- for 'between' and zoon- meaning animal or 'living being'. It is often called the 'Age of Medieval Life' or the 'Age of the Dinosaurs', after the dominant fauna of the era.
The Mesozoic was a time of tectonic, climatic and evolutionary activity. The continents gradually shifted from a state of connectedness into their present configuration, this rifting providing for speciation and other important evolutionary developments. The climate was exceptionally warm throughout the period, also playing an important role in the evolution and diversification of new animal species. By the end of the era, the basis of modern life was in place.