Palaeontologists announce major discovery in Tete: The largest petrified forest in Africa is in Mozambique

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Palaeontologists announce major discovery in Tete: The largest petrified forest in Africa is in Mozambique

6:12 CAT | 25 Aug 2017

Lusa / Portuguese Palaeontologist Ricardo Aaraujo, in Tete province

Palaeontologists yesterday announced the discovery, in Tete province, of the largest fossilised forest on the African continent.

The announcement was made by palaeontologists Dino Milisse, director of the Mozambican National Museum of Geology, Nelson Nhamutole, curator and head of the new Palaeontology Laboratory at the same institution and Ricardo Araújo, from the Portuguese Instituto Superior Técnico and the Museum of Lourinhã.

“This discovery contributes to our knowledge of how forests were in the Permian period, about 250 million years ago, period immediately before the extinction of more than 95 percent of life on earth, where ecosystems were totally destroyed,” Araújo said.

The discovery was a surprise for the scientific community. “[There are ] large, densely populated fossilised trunks found in an area of over more than 75 kilometres,” he said, giving as an example “trunks over 12 metres high, which means that the trees would be three times that height and over two metres in diameter”.

Palaeontologists believe that the trunks discovered belong to the ‘Dadoxylon’ tree genre, an ancient classification with many different species. Further study of the collected fossil material may not only confirm this hypothesis, but also discover determine new genera and new botanical species.

“The potential for new genera and new species is great,” said Araújo, and there was a need for some reclassification of what was already known.

The expedition during which made the discovery took place between July 29 and August 17 discovered three new paleaobotany sites and revisited two others.

Mozambique has the most fossilised Permian forest on the continent, and is among the six areas with the most fossilised forest in the world, along with South Africa, Namibia, Brazil, Antarctica and Zambia.

The expedition was carried by the Mozambican Museum of Geology and Portugal’s Museum and Instituto Superior Técnico of Lourinhã.

Image result for permian period eat africa

Learn about the time period took place between 299 to 251 million years ago

The Permian period, which ended in the largest mass extinction the Earth has ever known, began about 299 million years ago. The emerging supercontinent of Pangaea presented severe extremes of climate and environment due to its vast size. The south was cold and arid, with much of the region frozen under ice caps. Northern areas suffered increasingly from intense heat and great seasonal fluctuations between wet and dry conditions. The lush swamp forests of the Carboniferous were gradually replaced by conifers, seed ferns, and other drought-resistant plants.

Early reptiles were well placed to capitalize on the new environment. Shielded by their thicker, moisture-retaining skins, they moved in where amphibians had previously held sway. Over time, they became ideally suited to the desert-type habitats in which they thrive today.

Animal development

Being cold-blooded, reptiles had to find ways to deal with big daily variations in temperature, from below freezing at night to over 100 degrees Fahrenheit (38 degrees Celsius) during the day. Some of the primitive pelycosaurs, which measured up to ten feet (three meters) long, had sail-like structures on their backs that are thought to have acted as heat exchangers, catching the sun in the morning to help warm the sluggish creatures.

Later, other mammal-like reptiles known as therapsids found an internal solution to keeping warm—scientists suspect they eventually became warm-blooded, conserving heat generated through the breakdown of food. These more metabolically active reptiles, which could survive the harsh interior regions of Pangaea, became the dominant land animals of the late Permian.

The therapsids flourished during the Permian, rapidly evolving many different forms, ranging from dinosaur-like fanged flesh-eaters to plodding herbivores. Some species reached a huge size, weighing in at over a ton. In the latter part of the Permian, smaller varieties emerged, likely warm-blooded and covered in insulating hair. From them, mammals would arise.

The Permian seas came to be dominated by bony fishes with fan-shaped fins and thick, heavy scales. There were large reef communities that harboured squidlike nautiloids. Ammonoids, with their tightly coiled, spiral shells, are also widespread in the Permian fossil record.

Massive loss of life

The Permian, however, represented the last gasp for much early prehistoric life. The period, and the Paleozoic era, came to a calamitous close 251 million years ago, marking a biological dividing line that few animals crossed. The Permian extinction—the worst extinction event in the planet’s history—is estimated to have wiped out more than 90 percent of all marine species and 70 percent of land animals.

Various theories seek to explain this mass extinction. Some scientists think a series of volcanic eruptions pumped so much debris into the atmosphere that the sun was blocked out, causing a significant drop in temperature and preventing plant photosynthesis, which in turn caused food chains to collapse.

Other scientists point to global climate change, citing evidence for a period of sudden warming and cooling. These rapid extremes of conditions may have meant species were unable to adjust. Other theories include a catastrophic release of methane gas stored under the seabed, triggered by earthquakes or global warming, or a massive asteroid impact.

Perhaps a combination of factors was to blame. But whatever the cause, new animals and plants would evolve to fill the void. Not least among them: the dinosaurs.

Source: Lusa / National Geographic