ANCIENT ANIMAL SURVIVAL SECRETS

Discover the remarkable resilience of Earth's oldest and hardiest animals, overcoming mass extinctions and conquering the planet's ever-changing climate

- WORDS AILSA HARVEY

As animals that lived long before us and dominated Earth between 245 and 66 million years ago, we are fascinated by the dinosaurs.

Yet there are others alive today that lived alongside them, came before them and have remained relatively unchanged for hundreds of millions of years. Some have endured five mass extinction events and survived, while the dinosaurs were doomed to perish.

The key to a creature’s success over the course of geological eras varies, though there are some general traits that make its long-term survival more likely.

Firstly, they need to be adaptable and flexible. If a sudden mass-extinction event occurs and the conditions of its environment change suddenly, the speed at which an animal can adapt to these new – and often more hostile – conditions determines whether they survive or are wiped out. The next factor to consider is reproductive capability. Instead of being the toughest and longest living animals, some take a strength-in-numbers approach. Fast reproduction means that even if an animal lives a short life, it can reproduce and help maintain the population of its species within this short time. The less time there is between birth and reproduction in an animal's life cycle, the better the chances of producing offspring.

Complexity isn’t always the best approach. Some of the longest lasting inhabitants of Earth are those with a simple biological makeup that can adapt more easily to a changing environment and don’t need so much energy to sustain complex functions. This might mean that the animal is brainless, as brains demand huge amounts of a body's total energy for complex functions. The human brain, for example, uses up 20 per cent of your energy intake. So while humans may be considered one of the most advanced species, we have only existed for 200,000 years. In the grand scheme of things, we're a new life form and have not yet had a test of survival in the same way much older species have.