Human jaws might have evolved from placoderms’ jaw structure, as specialists say.
(Mirror Daily, United States) A new study from scientists shows that human jaws are related to fossil fish jaws. The ancient fish originates from China, and it lived more than four hundred million years ago. It belongs to the placoderms species, which is a bony fish species, the only one which shares features with humans in terms of jaws.
Placoderms are an extinct species, and they appeared in the early Silurian age. The fish is called Qilinyu and was an armored fish, just like the other members of the species. According to the study, body length could exceed twenty centimeters. The fossils have recently been found in a Chinese region, called Yunnan.
A team of Swedish and Chinese specialists was in charge of the new study. They explain that today, all vertebrates display a similar structure for their jaws, namely components such as the maxilla, the premaxilla, and the dentary. Human jaws are no exception from this rule.
Specialists state that the fossil fish jaws stand as the missing link in the evolution chain. They display similar structures for their jaws. So experts believe that human jaws evolved from this prehistorical fish forms.
A similar discovery was made three years ago. A placoderm fish skeleton, belonging to an Entelognathus, was found in the same Chinese area. The skeleton, also dating from the Silurian period, is similar to placoderms, but also displays features such as the maxilla, premaxilla, and dentary.
The new Qilinyu fossils stand as proof which reinforces the idea that fish jaw structures and the human ones are quite similar.
The specialists’ research concludes that the old gnathal plates identified in the Silurian fish are the starting point of the development of human jaws.
The Silurian age was the geologic period when bony and jawed fish thrived. Forms of land life also begin to appear back then, but they were microscopical. Most of them were plants living in the proximity of water, and anthropoids.
The new research from the Chinese and Swedish specialists was published in the journal Science. The study was a partnership between the Uppsala University in Sweden and the Institute of Vertebrate Paleontology and Paleoanthropology in China city capital, Beijing.
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