I would say that the fishes exhibited the greatest diversity (though the brachiopods also had considerable diversity) and mostly were of the ostracoderms (with a platey or shell-like skin and no jawbone) which exhibited many varieties and also the placoderm which had gills, a jawbone and fins so was developing characteristics of modern fish.
Explanation:
All animals are in one kingdom (called Kingdom Animalia); all plants are in another (Kingdom Plantae). ... Other systems have six or more kingdoms. Species are the smallest groups. A species consists of all the animals of the same type, who are able to breed and produce young of the same kind.
The three major types of pollution are air pollution, water pollution, and land pollution. Sometimes, air pollution is visible. A person can see dark smoke pour from the exhaust pipes of large trucks or factories, for example. More often, however, air pollution is invisible.
Assuming that Element X is neutral or the atom of element X is neutral or uncharged it will possess the same number of electrons which is 80.
Is this just in general or in a certain area?