Second Supereon

In our geological timescale, the Precambrian supereon (from 4.6 billion to 541 million years ago) set the stage to prepare our favourite players from the Animilia Kingdom to shine bright like the weird, wonderful and motile multi-cellular organisms that they are. In the Hadean eon, we are searching right at the back of grandpa's broom cupboard, and finding the earliest evidence of anything and everything. We say hello the formation of Earth itself, welcome the formation of our moon, and start to get serious about photosynthesis.

   But it is not until the as-yet-unnamed second supereon that we start to see the huge diversification of animal life, a process that started to really take wind during the Cambrian Explosion 541 million years ago.  During the Cambrian radiation , the spotlight shone on protists, a group of microorganisms made up of, amongst others, protozoa ('proto' - first, 'zoa' - animals), which were able to transform complex food particles into energy.

   The early protozoa were probably plant-eating organisms to begin with, but as food resources got scarce, the herbivore policy was forced to change and the process of hunting other microbes for food started - thus causing an early version of what we know as a food chain. This in turn caused evolutionary pressure to favour mutuations which enhanced defensive, sensory and mobility mechanisms. The protozoa also evolved protective strategies by way of organising themselves into large colonies, which was beneficial for protection from predators, and this led to the organisation of larger and more complex groups that would later evolve into metazoa - multicellular animals - ie, eventually you, me and the cat next door.

 And so, following possibly the shortest summary of the first 4 billion years of Earth ever, this blog PANGEA will look at some of the most unusual and interesting examples of metazoa that have graced our curious little planet. 99.99999% of all species that have lived here are now extinct - either through competitors, changing environment or evolutionary change - and this is a celebration of some of the weirdest and best.