Last december, we survived to the end of the world… Ok, that was a fairy tale. But what if something similar could happen? Can you imagine how it would feel to witness a massive extinction? The Earth has already witnessed FIVE of them! The biggest event was the Permian-Triassic one (also known as “the Great Dying”), about 250 million years ago, and it affected over 96% of all marine species. We are only seeing a negligible fraction of the descendants of the first marine organisms! Many years after, species returned to settle the sea, faster than they did in land. Paleontologists estimated that in about 10 million years, but discoveries like the one I’ll describe spoiled this calculus.
One of these new sea residents appeared eight million years after the Great Dying, and was discovered recently in Nevada. Nevada then was located in the Panthalassian Ocean, as the land masses were all together forming Pangea. Even though they discovered the first pieces in 1997, it wasn’t until 2010 when they tried to find more skeleton parts. Researchers found a very well preserved fossil, with a complete skull, the entire vertebral column, and the fins: is called Thalattoarchon saurophagis(which means “lizard-eating sovereign of the sea”).
This ichtyosaur was at least 28 feet (8.6m) long. It had a huge skull with a very strong jaw, armed with large (5” or 12,7cm) and sharp teeth. With them, the animal could eat other marine reptiles. Imagine huge reptiles, not the lizards you can find in your favourite park! Researchers say that the Thalattoarchon could eat an animal of its own size. Imagine the battle! An animal with the size of a bus eating another bus-sized animal. The only comparison we can do using modern animals is with orcas and great white sharks, because they also choose similar-size preys.
This animal was at the top of the food chain, it was a macropredator, so it had a lot of preys to choose (ecosystems rebuild from the bottom up). That means that the Earth recovered its biodiversity even sooner than expected, and that the ecosystems had the same structure as they have nowadays. It is believed that since the Thalattoarchon appeared, the predator niche has been occupied. That doesn’t mean that if something similar occurs right now, the Earth will recover itself with the same velocity. But it is really useful as we can now have an idea about how the biota react to catastrophic events.
If a massive extinction is happening right now, will the biota react better or worse than it did before? Are we restricting its reaction capability?