Millipedes first appeared on the Earth for 425 million years ago. To such conclusion the researchers who rated the age of the Silurian and Devonian deposits in the UK using the uranium-lead method of Dating zircons. According to their publication in the journal Historical Biology, first terrestrial arthropods lived in the thickets of primitive plants on the shores of lakes, however, after only 40 million years on Earth have any real forests with rich fauna.
Millipedes (Myriapoda) were the first animals that walked out of water onto land. Unfortunately, paleontologists are still poorly represent yourself, when and how it happened. According to estimates, made by the method of molecular clock, this group of invertebrates appeared in the late Cambrian, about 500 million years ago. However, the oldest known fossil centipedes are much younger.
The researchers, led by Michael Brookfield (Michael E. Brookfield) from the University of Texas at Austin decided to restore the first stages of the evolution of terrestrial centipedes. For this, they said the age of the deposits, which were discovered the earliest remains of these invertebrates. It’s three fields, one of which is located in the vicinity of the English town of Ludlow, and the other two in Scotland, on the Isle of Kerrera and the village of Cowie.
Using the uranium-lead method of Dating of the mineral zircon (ZrSiO4), the authors estimated the age of the deposits on Carrera 425-426 in millions of years, at Ludlow, in 420 million years, and Cowie in 413-414 million years. In Carrera were found centipede Kampecaris obanensis, which is due to a new Dating gained status as the oldest known to science.
This species inhabited the surroundings of a freshwater lake located in semi-arid areas. This apparent adaptations to breathing air, he was not. Apparently, the first centipede was tied to the swampy coastal thickets of primitive maxonii plants (Cooksonia).
As shown by fossils from Cowie, ten million years later, the fauna of centipedes and other terrestrial arthropods has become much more diverse. In particular, among them there were species which were previously considered the oldest centipede — Pneumodesmus newmani. It was assumed that his age is 428 million years, however, the reassessment also made by the team members of Brookfield, showedthat he is 13 million years younger.
According to the authors, the first land plants and animals evolved in parallel, and the process was very rapid in geological terms. In just 40 million years the community went from stunted thickets, examples huddled on the banks of ponds, to full of forests with a varied fauna.
Researchers believe that the close relationship of vascular plants and early terrestrial arthropods makes findings centipedes over 425 million years is very unlikely, because these invertebrates simply did not exist a suitable environment. And the results of the evaluations by the method of molecular clock, which indicate the earlier origins of centipedes, they explain the distortion resulting from the rapid evolution of this group.
In the past year in Burmese amber was discovered millipede Burmanopetalum inexpectatum the age of 99 million years. The morphology of this species was so unusual that it had to allocate a separate suborder.
Sergey Knee High