<span>There
was development of super continent Gondwana after Pannotia broke up. This led
to a largest number of creatures evolving such as algae and the armored
arthropods like trilobites. This period was referred to as Cambrian period in
the first Paleozoic era.</span>
Answer:
As the river erodes the landscape in the upper course, it winds and bends to avoid areas of hard rock. This creates interlocking spurs, which look a bit like the interlocking parts of a zip. When a river runs over alternating layers of hard and soft rock, rapids and waterfalls may form.
It is know as Rhythmic layering
Southeast Asia is divided into <span>a peninsula and several archipelagoes.</span>
