The Permian Extinction: A Catastrophic Event

Around 252 million years ago, a catastrophic event took place—so devastating that its exact cause remains a mystery. This event led to the mass extinction known as the Permian Extinction, which annihilated nearly all life forms.

This isn’t an exaggeration; this extinction event wiped out approximately 57% of biological families, 83% of genera, 81% of marine species, and 70% of terrestrial vertebrate species.

Trilobites? Extinct. Ancient fish? Gone. Corals and anemones? Eliminated. Nine distinct orders of insects were lost, and nearly all reptiles, the largest life forms at the time, faced extinction.

While the extinction did not eradicate all life, it severely hindered the regrowth of ecosystems for an estimated 4 to 6 million years, with full recovery taking close to 30 million years. During this recovery, certain small animal groups that found a successful ecological niche thrived, particularly a sub-order known as dicynodonts.

The Emergence of Lystrosaurus

In this post-apocalyptic world, plants rebounded more quickly than animals. As the foundational level of the food chain, plants flourished in a vacant environment devoid of predators. And then, Lystrosaurus appeared.

Fossil evidence reveals four distinct species of Lystrosaurus, varying in length from 2 to 8 feet, with most standing only a foot or two tall. These herbivores featured beaks, two tusks resembling those of pigs, and grinding teeth adapted for plant consumption, along with leathery, hairless skin.

Lystrosaurus is believed to be among the first animals to emerge after the Permian Extinction and thrived in its wake. For millions of years, as indicated by fossil records, Lystrosaurus was essentially the sole land vertebrate.

Imagine this world: plants, insects, a few fish in the oceans—and four species of small, pig-like, plant-eating creatures. That was it.

Several theories attempt to explain why this specific species survived an extinction event that eliminated so many others:

1. Lystrosaurus may have had the ability to enter a hibernation-like state known as torpor, as suggested by the thin growth rings found in its fossilized tusks.
2. Its short, sturdy legs were likely well-suited for burrowing, providing protection and enhancing survival in low-oxygen environments.
3. Lystrosaurus might have been a generalist herbivore, capable of subsisting on the limited plant species that survived the extinction.
4. It likely reproduced and matured rapidly, allowing it to dominate after slower-growing competitors were eliminated.
5. Lastly, luck may have played a significant role in its survival. Scientists acknowledge that, regardless of adaptations, chance can influence outcomes.

How Do We Define Success?

Lystrosaurus is no longer present today. Although it existed 250 million years ago, it shares a closer relation to modern mammals than it does to dinosaurs or today’s reptiles. In a distant sense, humans are descendants of Lystrosaurus!

But how do we define success? Is it determined by the duration a species has remained unchanged? If so, sea sponges and jellyfish, both virtually unchanged for over 500 million years, would be the winners.

Alternatively, is success measured by the dominance a species holds in the planet’s biosphere? By that standard, Lystrosaurus could be considered the most successful animal to have ever existed, a record likely unmatched unless another mass extinction occurs, leaving a sole surviving species.

While Lystrosaurus lacked the intelligence of humans, and did not create complex civilizations or launch spacecraft, humans have yet to endure for millions of years. As of now, it seems increasingly uncertain whether we can persist as long as Lystrosaurus once did.

Life is an ever-evolving game of survival, where varying conditions can either facilitate or hinder a species' position. Approximately 250 million years ago, a massive extinction event reshaped the landscape, paving the way for a small group of herbivores to become one of the most dominant life forms for millions of years.

This serves as a reminder: one doesn’t need to be the apex predator, the fastest, or the strongest. If a modest, burrowing, stout-legged herbivore can thrive as the most successful land animal for millions of years, then success is achievable for all of us!