Jawsos

Jawless Fish, also referred to as Jawsos in scientific literature, are a group of ancient fish that lived during the Cambrian to Silurian periods. These animals evolved from ancestors with paired fins and jaws, and are characterized by the absence of jawbones. The absence of a jawbone led to significant changes in the feeding behavior and feeding structures of these animals.

Jawless fish were among the first vertebrates to appear on Earth, playing a crucial role in the early evolution of animal life on the planet. They were characterized by gill slits, paired fins, and a dorsal and anal fin. Some jawless fish were armored with dermal scales, while others had skin or possibly bony plates as protection.

One of the most significant jawless fish species is the Myllokunmingia. Fossil evidence suggests that these ancient creatures were only a few centimeters long and were characterized by the presence of a skull with gill slits. The Myllokunmingia fossils were discovered in the early-Ordovician period, making it an early example of the evolution of vertebrates. Hadrosharkas, another jawless fish species, was found in the early-Ordovician period and had jaw-like structures that suggest it may not be entirely jawless after all.

Fossil records indicate that jawless fish were among the dominant species in early oceans. However, their diversity decreased significantly with the appearance of jawed fish, which became more prominent with the development of jaws. Jawless fish eventually became extinct, but their legacy can be seen in the development of modern vertebrates.