In a new study, American paleontologists have found the first evidence of complex respiratory organs in sea creatures that are 450 million years old.
Trilobites are an extinct class of marine arthropods that appeared on Earth in the early Cambrian period, about 521 million years ago. They are called an evolutionarily successful species because they survived for 250 million years – longer than dinosaurs.
In the course of the new work, scientists studied several hundred prints of the bodies of trilobites of the species Triarthrus eatoni in order to compile a detailed description of their structure, since it was not previously known about this.
It turned out that the limbs of these trilobites were covered with feather-like and dumbbell-like outgrowths, which were similar to the gills of modern horseshoe crabs, lobsters and some other invertebrates.
According to biologists, trilobites could have gill structures in the upper extremities, with the help of which they breathed.
It is not yet clear how trilobites protected their gills from damage and pollution. The authors hope that it will be possible to find out in the course of further research.