Found a broken egg shell about 80 million years ago, which may be a dinosaur egg

Fossil specimens of dinosaur eggs, broken eggshells, etc., found in Shanyang, Shaanxi, and Laiyang, Shandong, about 80 million years ago. Photo by Sun Zifa, a reporter from China News Service

In recent years, the earliest fragmented eggshell fossils about 80 million years ago were discovered in Shanyang, Shaanxi and Laiyang, Shandong. Who laid the eggs?

The latest research by Wang Xiaolin's team from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences (Institute of Paleospine, Chinese Academy of Sciences) believes that they are less different from the dinosaur egg species in the Nanxiong Basin of Guangdong-Pingling Laminated Eggs, and the North American Citrus The egg shells are similar, and it is speculated that the mother dinosaur may belong to the hadrosauridae.

This paper on the latest research progress in the field of paleontological fossils was recently published online by the international professional academic journal "Historical Biology". The study also conducted an in-depth analysis of the round egg family fossil classification of dinosaur eggs, and revised the classification positions of other round egg family members at home and abroad. It also provided new evidence for the discussion of the egg-laying mothers of this type of dinosaur egg.

Wang Qiang (left), associate researcher of the Institute of Paleospine, Chinese Academy of Sciences, and Zhu Xufeng, a doctoral student, introduced the latest developments in the study of dinosaur egg fossils. Photo by China News Agency reporter Sun Zifa

and Dinosaur Egg Pingling Laminated Eggs are small

Corresponding author of the paper, associate researcher of the Institute of Palaeospine, Chinese Academy of Sciences Wang Qiang and the first author of the paper, Zhu Xufeng, doctoral student at the Institute of Palaeospine of the Chinese Academy of Sciences On the 20th, I was interviewed by reporters on the latest research results in Beijing.

Zhu Xufeng said that in recent years, the research team has collected a large number of dinosaur egg shell fragments in the Shanyang Basin of Shaanxi Province and the Laiyang Basin of Shandong Province. The fossil age is about 80 million to 66 million years ago.

When they were studying the diversity of dinosaur eggs in each basin, they found some materials that could be compared with the Laminae Laminae of the genus Dinosaur in Nanxiong Basin, Guangdong. The research team further studied the dinosaur egg materials newly discovered in Shanlu and the original materials of Pingling laminated eggs, and found that the dinosaur egg materials of Shanlu had egg shell decoration, egg shell microstructure pattern, shell unit morphology, stomata morphology, etc. Compared with the original materials of Pingling laminated eggs, the differences are small, and these differences are not enough to establish new egg species. Therefore, the new materials of dinosaur eggs from the two places in Shanlu are classified as Pingling laminated eggs.The egg species has so far found very few fossil materials in China, and lacks a complete egg body, so it cannot be classified as a known egg family.

Zhu Xufeng, a doctoral student at the Institute of Paleospine, Chinese Academy of Sciences, demonstrates the research process of dinosaur egg fossils in the laboratory. Photo by Sun Zifa, a reporter from China News Service

is very similar to the eggshell structure of the North American Citrusaurus

. The ridge stack egg has a small difference, and the eggshell of the hadrosaurid dinosaur Ceratosaurus found in North America also has very similar microstructure characteristics, which may be related to members of the hadrosaurid dinosaur.

Zhu Xufeng said that for a long time, Citrus eggs have been regarded as members of the round egg family. This in-depth study of the Pingling laminated eggs found in China shows that this type of egg shell is quite different from the round egg family. It is not suitable for the round egg family. Therefore, the latest research has revised the classification positions of some members of the round egg family found at home and abroad, and also provided new evidence for the discussion of the egg-laying mothers of this type of dinosaur egg.

Pingling laminated egg shell fragments, a, b, and c represent materials from Nanxiong, Shanyang, and Laiyang respectively. Photo courtesy of the research team

Revised the genus and classification of dinosaur eggs

As the most important result of this research, the research team of the Chinese Academy of Sciences completed the revision of the characteristics of the dinosaur eggs and the original The classification of related dinosaur egg fossils is revised.

Previously, Pingling Laminated Eggs had been classified into the Big Round Egg Family of Dinosaur Eggs. According to the analysis of the research team, the Pingling layered eggs and the big round egg family are quite different in terms of surface decoration and shell unit fusion, and it is not appropriate to place the Pingling layered eggs in the big round egg family.

Pingling laminated egg (top) and Jiangjunding round egg (bottom) shell diameter section microstructure comparison. Photo courtesy of the research team Photo by

According to the research and description of some types of dinosaur eggs that have similar outer surface textures and eggshell microstructures to the Pingling Laminated Eggs, including the famous Citrusaurus eggs in the Upper Cretaceous of North America,These dinosaur eggs are often classified into the round egg family.

The research team compared the descriptions and photomicrographs of these "round eggs" in Asia, North America, and Europe, and found that these "round eggs" are quite different from the general top round eggs found in Laiyang, and it is difficult to return them. Into the round egg family.

The research team specifically suggested that the round eggs of Citrusaurus found in the Gobi Desert of the Mongolian Plateau, the fine-layered para-round eggs from Shanyang, Shaanxi, and the unnamed round eggshells in the Jaisan Basin of Kazakhstan should be included. Pingling Laminated Eggs; the Alberta round eggs found in Alberta, Canada and the Europa round eggs found in Spain were revised as members of the genus Lamellar; the eggs of the celestial dragon in North America are also classified as members of the genus Lamellar.

Pingling laminated egg shell decoration and stomata opening characteristics. The upper, middle and lower parts are materials from Nanxiong, Shanyang and Laiyang respectively. Photo courtesy of the research team

lays the foundation for the study of the relationship between dinosaur eggs and dinosaurs

Wang Qiang pointed out that it is very difficult to confirm the types of dinosaur eggs and their relationship with the laying mothers, and there are only a few types of dinosaur eggs. The parent dinosaurs can be confirmed, including long-shaped eggs (egypterosaurus) and prismatic eggs (strodontodons). Due to the close relationship between Pingling Laminated Eggs and Citrusaurus eggs, it is reasonable to believe that its mother dinosaur may belong to the hadrosauridae.

He said that the study by the Institute of Paleospine of the Chinese Academy of Sciences not only enriched dinosaur egg species, clarified the domestic and international distribution of Pingling laminated eggs, and further revised the foreign classification of some round eggs dinosaur eggs.

Pingling laminated egg (upper, middle) and Jiangjunding round egg (lower) eggshell chord microstructure comparison. Photo courtesy of the research team

Through this study, it is further clarified that when establishing the relationship between dinosaur eggs and dinosaurs, more will be based on finding embryos in dinosaur eggs, or juvenile dinosaurs and dinosaurs in the same layer. The close relationship between the eggs "provides a good basis for us to establish the relationship between dinosaurs in different locations, different layers, and different eras throughout the Cretaceous period." Wang Qiang said.

(Source: China News Network)