The recent discovery of an ancient fish fossil in China with a particular type of jawbone has evolutionary scientists intrigued. The discovery may provide clues to how the jaws of fish evolved to become the jawbone we have today.
Researchers recently discovered a 423-million-year-old fossil of an armored fish in China. After analyzing the fossil found that it belonged to an armored fish which had a head like a dolphin and was part of a strange group of animals known as placoderms.
The jawbone of the new fish fossil has several similarities with other land animals, which have led scientists to conclude that the jaws of modern land vertebrates and other bony fish have originated from placoderms. This recent discovery which has been called Qilinyu rostrate, coupled with a different placoderm fossil found in 2013, may lead to scientists to a revolution in the story of the evolution of early vertebrates.
The main reason for why these two discoveries are so important is that they can change the established of evolution while our ancestors were just fish. Normally, every vertebrate animal has a specific set of bones in the head. Observing fish fossils, the scientists saw the placoderms have jaws but their bones were very unusual. This led to the believe that three-part jaws of modern humans had originated in other bony fish while dismissing placoderms as a weird branch of the vertebrate tree.
This theory was disputed in 2013 when Per Ahlberg, a paleontologist at the Uppsala University in Sweden, and his colleagues found a fish fossil with the body characteristics of a placoderm but the jaws of a bony fish. The more recent discovery only serves to reinforce the idea that placoderms weren’t just an independent branch of evolution but may have been the ancestors of bony fish.
The initial view has allowed to take root simply because scientists did not find any link between placoderms and bony fish. The two recent discoveries changed all this by providing an intermediary evolutionary link between the two types of fish specimens, placoderms with the unusual jaw and the bony fish with a jawbone more similar to our own.
What do you think about the discovery of the fish fossil?
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