Evolution ordered that our fish ancestors were cross-finned fish, of which only relic coelacanth now exists, which certainly deserves a separate article in the future.
However, the evolution of the emergence of fish on land could go in a completely different scenario, and, perhaps, even in due time, it did.
Before us are ancient extinct fish that had every chance of becoming progressive land creatures, but something went wrong. These guys swam in the waters of the young Earth between 430 and 250 million years ago, and they were called acantodes.
The animals differed from ordinary fish, first of all, in a large number of fins, which in many species turned into sharp thorns, which served as a protection and a way of moving through labyrinths in the then heavily littered water.
Based on the remains, this class of fish was successful, and spiked herrings have spread across the globe, including both salty oceans and fresh rivers and lakes. The length of different species ranges up to 2 meters. The specializations were very different. Some ate plankton, some meat, some seaweed.
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What is the trick of these spiked fossils. Let's return to the recent material on the theory of probability of biological systems. Unlike their cross-finned relatives, it has been suggested that the evolutionary potential on land for the Akandod was much higher. It's all about their huge number of additional specialized fins, the number of which in some species reached 6-7 pairs. A sort of centipede fish, considering that most often the fins were spines or ossified legs.
Let's compare the two scenarios. In the first, cross-finned fishes (our ancestors) on their wretched soft fins insanely slowly master the land, simultaneously turning into amphibians. They move sluggishly, because on four weak legs you cannot run far. The nervous system sucks, because in order to keep a big head on weight, you also need normal support. Hunting is difficult, because you only have a mouth. But despite all the shortcomings, cross-finned fish were able to win the evolutionary race, giving rise to both dinosaurs and mammals.
Second option. Acanthodes nevertheless thought of going ashore. They have a huge plus - a huge number of ossified limbs, which, depending on the conditions, can be transformed as desired. Acantodes do not have problems with fast movement, because on small sharp legs you can very quickly run along the shore, as crabs have been successfully doing for millions of years. There are grounds for the development of complex nervous activity, since good support makes it possible to enlarge the skull. Hunting can be insanely convenient. You can use your sharp legs as a spoke, or you can transform the front pair of sharp legs into prototypes of hands, and the transition to a protein diet is also a prerequisite for brain development.
In the second scenario, acantodes would most likely oust their cross-finned competitors and there would be no amphibians, dinosaurs, birds, mammals. But something would be much more interesting. For example, a super-developed civilization of the descendants of Acanthodes that existed as much as 300 million years ago.
And, however, perhaps it was so? For such a period, acantodes would have long ago become higher beings, conquered the galaxy, or even passed into another dimension, becoming what can be very carefully called God.
Author: MauganRa