Over time, all living things have evolved in some way. The process still continues today. Even though there are species that have disappeared, new ones are being discovered since many plants and animals have different ways of adapting. One adaptation that scientists are now looking at is how animals, and especially humans, have come to have jaws.
Jaws, just like much of our other body parts, have been the result of adaptation through the ages. Scientists might have an answer as to how such an adaptation happened with an ancient fish that has been found. The fish is a 423 million-year-old species from China, according to Science News. The fish has been given the scientific name Qiinyu rostrata.
The new fish species belong to a group known as placoderms. For a long time, scientists have thought that these fishes were strange since their jaws were not like that of most animals living today.
"They look like sheer metal cutters," said Per Ahleberg, a paleontologist from the Uppsala University in Sweden. "They're these horrible bony blades that slice together."
The interesting feature of the new fish found is that it has the body of a placoderm, but also has the jaw like that of a modern-day fish, as noted by Science Daily. It had the three-part jaw that modern living beings, including fishes, have yet still had the body of a placoderm. The new fish is connected to a placoderm found earlier, Entelognathus primordialis in that both have a three-part jaw.
With the discovery of two types of placoderms with the same type of jaws, the two can be seen as an intermediate step between the earlier placoderms and the bony fishes of today. The Qiinyu fish is also rather small, as it has been compared to the size of a box of tissues. Placoderms then aren't an evolutionary dead-end as some see, but now are more an evolutionary step from an ancient form to a more evolved one, at least as far as animal jaws are concerned.
Also recently an ancient ancestor of the bison has been found in cave paintings.
