Remember that 400 million-year-old fossilized picture of an ancient fish that looks like an emoji? ↓↓
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Caption: The Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences discovered for the first time in Wuning a new genus of true armored fish: Junqing Qingshui and Hedgehog Anji .
Recently, in Qujingsu, Yunnan Province, which is known as the “Kingdom of Ancient Fish”, Chinese paleontologists have discovered the “Second Emoji Pack”!
Journal of Vertebrate Paleontology recently published a new study on the true armored fish online. Chinese researchers discovered a new genus of true armored fish in the 410 million-year-old Xitun Formation in the Qujing area of eastern Yunnan: Shuoda Xitun fish.
The ecological restoration map of Shuoda Xitun fish (painted by Shi Aijuan).
“This is the first time to discover the true armored fish in the Xitun Formation in the Qujing area. This fish has typical characteristics of the true armored fish and belongs to the true armored fish order. There is no doubt about the fish family. This discovery fills the gap where no real armored fish has been seen in the Xitun Formation.” On April 18, in an interview with a reporter from Science and Technology Daily, Zhao Wenjin, a researcher at the Institute of Paleo-Spine of the Chinese Academy of Sciences, said.
Since the 1960s, paleontologists have discovered a wide variety of ancient fish fossils in the Early Devonian strata exposed at the foot of Xicuifeng Mountain in Qujing City, Yunnan Province. This step by step uncovers the mystery of the evolution of ancient fish.
The Xitun vertebrate group represented by polygill, Yunnan fish, Yang’s fish, etc. has long been known all over the world, and it is the most famous Early Devonian spine in the world. One of the treasure houses of animal fossils, it has received extensive attention from the early vertebrates. These fossils are mainly produced in the Xitun Formation near Xitun Village, Xicheng Street, Qilin District, Qujing.
However, “so far, in the Xitun Formation, the main output area of the Xitun vertebrate group, no important group of armored fish has been found. The exact report of the class.” Zhao Wenjin emphasized.
Photos of Shuoda Xitun fish fossils (photographed by Gai Zhikun), 3D reconstruction and restoration of head armor (painted by Feng Mingjuan).
In recent years, the early vertebrate evolution research team of the Institute of Paleovertebral Science, Chinese Academy of Sciences has continued to carry out field excavations of fish fossils in the Lower Devonian Xitun Formation in the Qujing area. A large number of ancient fish fossil materials have been obtained, among which 5 armored fish specimens have typical characteristics of the eutherididae, which should be a new genus of eutheridus.
Zhao Wenjin introduced that the true armored fish is an extinct type of fish that “wears” armor. It is a kind of jawless fish unique to East Asia. In my country and northern Vietnam, it is a very indigenous fish.
“The genus name of the newly discovered giant Xitun fish indicates that it was found in the Xitun Formation near Xitun Village, Qujing, and the species name is derived from its large head. A.” Zhao Wenjin said.
Based on previous phylogenetic analysis of armored fishes, combined with new understanding of some characteristics of Xitun fish, the researchers constructed a phylogenetic analysis including 66 characteristics. The new matrix of , in which 3 new features are added are the presence or absence of the central canal, the thickness of the head armor and the presence or absence of remnants of the central transverse canal.
The results of the latest phylogenetic analysis show that the genus Xitun fishes, together with the genus Shieldfish and the genus Euryphae, form a monophyletic group—the branch of Eurydidae, And among the three, Xitun fish and shield fish are more closely related.
Meanwhile, the sensory duct system of Xitun fish has primitive and derived mosaic features. This discovery provides new key evidence for exploring the evolution of the sensory duct system in armored fish.
In this regard, Zhao Wenjin said that this study not only filled the geological gap between the Xishancun Formation and the Xujiachong Formation during the Early Devonian of the true armored fish in the Qujing area, but also It enriched the fish diversity of the Xitun vertebrate group, and helped us to further clarify the phylogenetic relationship between the various groups of the true armored fish, and deepened our understanding of the radiation evolution of the armored fish subclass in the Early Devonian. cognition.
Source: Science and Technology Daily