Meetings on May 25th and June 22nd
In our May and June meetings, David Saville continued his exploration of life on Earth looking at the Permian and Triassic periods.
In the Permian (299 – 252 mya), the wet climate of the Carboniferous was slowly replaced by a land dominated environment. This saw the development of a fully terrestrial fauna and the appearance of the first large land herbivores and carnivores. A mass extinction event then took place at the end of the Permian and is thought to have been caused by the flood basalt eruptions that created the Siberian Traps.
In the second half of the May meeting, Jane Harrison gave an excellent talk on the Geology of Guernsey from her recent holiday to this Channel Island.
In June, David took us through the Triassic (252-201 mya) period which followed this major mass extinction. The formation of a single supercontinent, called Pangaea, led to increases in temperature and greater aridity and life had to adapt. Plants, for example, developed waxy, needle-like leaves to help retain moisture and seeds evolved as they were more drought-resistant than spores. Insects continued to evolve but amphibians numbers declined as water resources shrank. Reptiles dominated. Most lived on the coastal margins or in the sea. Pterosaurs, which were the first to develop powered flight, bore superficial resemblance to dinosaurs but had evolved on a separate evolutionary branch. True dinosaurs appeared later in the Triassic, as did the first mammals, which were small shrew-like creatures. Some of these weird and wonderful animals were brought to life on a video.
Bob concluded the June meeting with some of the geological events that have recently been in the news.
Our next meeting will be at The Witham on Monday morning July 27th at 10 am. All are welcome to join us. Please contact the convenor for details.
Report by Bob Tuddenham and Jane Harrison