Surprising fossils bring confusion in the mammalian family tree   Leave a comment


  • Megaconus ("Big hump") lived 165 million years ago in what is now China, was ground dwellers and vegetarians.
     Megaconus (“Big hump”) lived 165 million years ago in what is now China, was ground dwellers and vegetarians.
  • This excellently maintained find was a completely new light on the shape of the original mammal.
     This excellently maintained find was a completely new light on the shape of the original mammal.

    Arboroharamiya jenkinsi also lived 165 million years ago in what is now China, but quite different Megaconus: namely trees and as insectivores.

  • Arboroharamiya jenkinsi also lived 165 million years ago in what is now China, but quite different Megaconus: namely trees and as insectivores.

The two rat-sized animals lived about 165 million years ago in what is now China, but were otherwise completely different in almost every respect

London / Bonn / Vienna – For over a century, paleontologists knew only the teeth of the animal. And they were strange enough, the molars had cusps that is what the paleontologists suggested that the animals have crushed plant food. This gave the creature the name: Megaconus called in German “Big Mute”.

However, as the corresponding animal really looked like, which remained a mystery for over 100 years – that could be solved thanks to a spectacular Funds in the northeast of China now. Researchers led by Thomas Martin and Zhe-Xi Luo, both of the Steinmann-Institute, University of Bonn, lay in the journal “Nature”, a detailed analysis of the 165 million years old skeleton ago, the locals had found.

Because of the bone structure, the 250 grams, primal mammal was the size of a rat today, should have moved slowly on the ground, the researchers suggest. Nevertheless Megaconus was probably not have been easy prey for enemies: he has (see illustration above left) has a shot blocked well with poison glands on the hind legs his enemies.

The animals lived about 40 million years before the first true common ancestors of today’s mammals. And unlike their contemporaries they subsisted not insects. The teeth were far from Megaconus an unusual specialization of dentition, Martin and his colleagues write. This in turn means the special adjustments are not a privilege of modern mammals.

More confusion in the family tree of mammals takes a second, similarly ancient origin mammalian Fund from China, which is also presented in “Nature”. In this case, it is a species which was christened the name Arboroharamiya.Unlike Megaconus, who lived on the ground, like this little four-legged friend was adapted to living in trees and eating insects.

In an accompanying commentary in “Nature” it is said that the two discoveries have quite different implications for the origin of mammals. Its roots trace back one must now probably a little more, namely 200 million years. 

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Posted August 8, 2013 by kitokinimi in Uncategorized

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