Re: Which animal holds the record for 'longest dominator of Earth'?

No single species has ever managed to "dominate" the world. A species that does well can do well in one area, but it will never show up in enough places to dominate the whole world. This means I'll have to answer with some larger groups.

Defining what one means by a group of animals dominating is a bit vague; tiny creatures called phytoplankton are the base for most life in the sea, but you wouldn't notice them without a microscope and they get eaten by all sorts of other creatures. They may be important, but it would be hard to call them dominant! I'll give you two groups, one in the ocean and one on land, that have been around for a long time, have a lot of species, and are still going strong.

In the ocean, fish would be the dominant group of animals. The first jawed fish showed up over 410 million years ago, and they've been doing well for over 370 million years. They are at the top of the food web, they have a lot of species, and they are key parts of almost all the ecosystems that they are a part of.

On land, the dominant animals are definitely the insects. About half of all the species that have been discovered are insects. They are found virtually everywhere on the earth. Although insects may be small, their large population means that the weight of all the insects in the world is many times the weight of all the people! Dinosaurs were dominant for a hundred million years or so, but insects first show up as fossils from 300 million years ago.

What about people? We've managed to dominate the world, no doubt about that, but we've only managed to do that in the past fifty or so years, which is nothing compared to fish or insects.