Life on Earth is in a constant race to change and adapt, both to itself and the world around it.
About the only thing that is a constant in the natural world is that there is no constant!
Just a quick look at our fossil records and sadly, the current mass extinction event going on in the wilds of today is proof of that.
Animals that have been icons and staples of the natural world, from the elephants to the whales, to lions and tigers, to the panda, are disappearing, animals that feel like such monoliths of natural beauty are fading away into the bedrock of extinction.
Creatures that seemed too successful to fail or disappear, such as the dinosaurs and woolly mammoth, which seem so powerful and unstoppable, have been proven by their absence in today’s world, to be just a stone’s throw away from disappearing (well, technically the stone has to be at least 6 miles across and from outer space, but the point still stands).
However, then some aspects of the natural world seem to have been around forever.
Take trees for example. Whilst many orders and species have come and gone, it all feels like they have been here since the very beginning.
Even some animal groups feel like a part of this. Some groups, such as sharks, feel like they have been around forever.
However, what if I told you that not only have they only been around for a fraction of it, but that one is older than the other?
In this guide to our natural history, we are going to show you when these two groups of life first arrived in our natural history, as well as whether or not sharks, the king of the sea are trees, the towering greenery of the land. The answer might just surprise you!
Evolution of Sharks
So, before we start exploring the very long and very widening history of trees, let’s take a look at our fishier entry in this guide first!
Sharks as a group are part of the wider family of fish, which, as a whole, are largely aquatic vertebra animals that have gills and limbs that do not have any digits.
This may seem like very basic information to cover.
But it is vital information, as when we are discussing the evolution of sharks, we are also discussing the evolution of many orders of animals that are alive today, and many more that have lived throughout Earth’s history.
Animal life as we know it started to evolve in the Cambrian period of Earth’s history, some 585 million years ago.
It was so long ago, that very little life existed on land, if any, outside of a few microbiological organisms.
Among the first two distinct groups to evolve during the middle to late Cambrian, around 535 million years ago, were invertebrates, animals that lack a backbone, which include a wide variety of life, from jellyfish to squid, to scorpions.
The other, vertebrates, started with only very small, finless, and jawless fish species.
It is these primitive that give rise to every other back-boned animal on Earth, from frogs to primates, to elephants, to us, and sharks.
When it comes to sharks as we know them, the first signs of the ancestors of sharks, if not sharks themselves, are during the following geological period, the Ordovician, around 450 million years ago.
This is when we start to find fossils of shark scales in rocks from this period, though the fact that no teeth have been found, usually the only trait that sharks leave in the fossil records, means that this is somewhat questionable.
However, between the late Ordovician and the early Devonian, between 420 million and 380 million years, we start to see the first true shark species evolving.
Evolution of Trees
So, if Shark Evolved around the 400 million year mark when did trees first appear on land?
The interesting observation that many paleontologists and geologists will tell you, is that large forms of life on land are more difficult to support than in the water, as does not have the same buoyancy that counteracts gravity on an organism’s body.
Because of this, virtually any form of life, never mind just trees, doesn’t appear in our fossil records until much later than in the oceans.
Generally speaking, the first plants start to appear on land around 400 to 380 million years ago.
The main thing that allowed these early land pioneers to survive was their vascular system, which helped the plants stand up straight up and not fall under their weight.
By the time of the Carboniferous, around 360 million years ago, we start to see the emergence of trees as we would recognize them, as large plants with woody branches.
However, trees such as pines, flowering trees, and even conifers, would not appear for at least another 100 million years.
Are Sharks Older Than Trees?
So, based on what we have discussed, we can see that the first sharks predate the earliest trees on the land, and by quite a considerable amount of time!
Even at the latest point for sharks to evolve, they are some 20 million years older than the first true trees as we recognize them appearing, and the gap is potentially even larger!
Are Sharks Living Fossils?
Because of the age of the group, some people think that sharks are living fossils, but this is a misunderstanding of what the term means.
Living fossils are animals that have changed little, if at all, for millions of years. And while the group has been around for a long time, they have seen major changes too.
The first sharks look nothing like the hammerhead and great whites today.
So, it turns out that sharks are older than trees.
So, next time you see a shark, pay it some respect. In the story of life on earth, it’s a senior citizen!
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