The most complete full-bone fish evolutionary tree reconstruction to date

Source: Science and Technology Daily

Science and Technology Daily News (reporter Zhao Hanbin) Xu Guanghui, a researcher at the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, recently introduced to reporters that he has recently made a breakthrough in the comprehensive research on the early evolution of whole bone fish represented by Luoping strong fish 244 million years ago. The study described the skeletal morphology of the Robust Fish of Luoping, revealed some evolutionaryly important evolutionary sequences of skull features in whole-bone fish, and reconstructed the most complete evolutionary tree of whole-bone fish to date. The research results are published in the international academic journal PeerJ.

Researcher Xu Guanghui introduced that whole bone fish are divided into reaming fish and near-herring, and sparrow and bowfin fish are their living representatives. Luoping strong fish is the largest whole bone fish in the Luoping biota in Yunnan, with a total length of up to 40 cm, which is the largest whole bone fish genus found in the Middle Triassic strata worldwide 237 million to 247 million years ago, and has important potential value for reconstructing the ecological environment of marine vertebrates in the Triassic Period. Since it was first reported and named in 2014, the Ropin strong fish is a fossil species that has attracted much attention in the study of whole bone fish. However, due to the scarcity of fossils and the uncertainty of some key skeletal features, researchers disagree whether the Robust Fish of Luoping belongs to the near-herring or the reaming fish.

Researcher Xu Guanghui compared 9 newly collected fossil specimens with previous model specimens. In a 33-page paper, he described in detail the skeletal morphology of the Robust Fish of Luoping, revealing many new anatomical information and clarifying controversies over many key skull features such as square cheekbones, sequelbones, parasphenoid bones, hyoid jaws, and many other key skull features. "Previously, it was thought that square cheekbones were unique to articulated fish, and the presence or absence of bone extensions and square cheekbones was used as a sign to distinguish between the two types of fish. But in fact, I found that in the 4 genus of the near-herring, square cheekbones are also present, and in the Luoping strong fish, both bones are present, which also confirms that the two fish have a common ancestor. Researcher Xu Guanghui told reporters that on the basis of detailed comparative anatomy work, he included the Luoping strong fish into a large-scale branch systematic study, solved the problem of systematic classification, and confirmed that the Luoping strong fish is one of the earliest representative species of the near-herring predicted fish order.

The new research breaks through the previous use of arthial fish and herring as two independent research groups, including 60 fossil and 224 morphological characteristics of living genera, the two whole bone fish as a whole analysis and study, reconstructing the most complete whole bone fish evolution tree to date, providing a new perspective for understanding the early evolution, paleoecology and paleogeography of herring.