Dinosaur egg morphological characteristics

The first dinosaur eggs discovered were those of Protoceratops, which were oval in shape, about 7.5 cm wide and 15 cm long, and there were up to 30 of them, with the egg tips pointing inward and arranged in a spiral shape in the nest. Dinosaur eggs are amniotic eggs. The amniotic eggs are covered with a calcium shell that is both strong and resistant to drying. There are many small pores on the shell. These pores are "windows" for the embryo to breathe air during development. The eggshell is 2 to 7 mm thick, making it the thickest eggshell in the world. Inside the eggshell, there is a large yolk that supplies nutrients to the embryo. An amniotic sac surrounded by amniotic membrane is filled with amniotic fluid in which the embryo is immersed. There is also a sac for storing excrement. The amniotic egg has a delicate and reasonable structure and will not dry out or lose water on land. The embryo is safe and comfortable inside. Dinosaur eggs come in various shapes, but their diameters are mostly between 10 and 15 centimeters. There are approximately thousands of dinosaur eggs found around the world. A dinosaur egg fossil with a long diameter of 30.48 cm and a short diameter of 25.4 cm was discovered in France. This is the largest known dinosaur egg fossil in the world.
What was found at that time were only two broken egg fragments, and it was unclear what animal egg fossil fragments they belonged to. Later, after studying the microstructure of the egg fragments, it was found that its microstructure was similar to that of a turtle egg, so it was believed that the two broken egg fragments belonged to an unknown reptile. Shortly afterwards, many broken egg fragments and some complete egg fossils of different sizes and shapes were discovered in the Cretaceous strata of southern France. The microstructure of the egg fragments was also similar to that of turtle eggs, and they must also belong to reptile egg fossils. . So, what type of reptile do these egg fossils belong to? Because the diameter of the egg fossils discovered at that time was relatively large, some were larger than 20 centimeters in diameter, much larger than turtle eggs. Among reptiles at that time, only dinosaurs could lay such large eggs, so the egg fossils discovered were called for dinosaur eggs. Since then, some dinosaur egg fossils have been discovered in the Cretaceous strata in many countries around the world. Since the number of dinosaur egg fossils found worldwide is not large (no more than 500), what is seen is generally the calcium shell of the egg. It is very rare to find eggs containing certain dinosaur embryo fossils. It is difficult to Determine which type of dinosaur the egg fossils found were produced by. Therefore, for a long period of time, the research on dinosaur egg fossils did not make important progress. Dinosaurs are oviparous animals that hatch to produce new generations through fertilization. Therefore, the discovery and study of dinosaur egg fossils is of great scientific significance for revealing the reproductive habits, behavior, living environment and causes of extinction of dinosaurs.
Our country is a country with extremely rich reserves of dinosaur egg fossils in the world. According to research, the shapes of dinosaur egg fossils include round, oval, oval, oblong and olive shapes. The outer surface of the eggshell is smooth or dotted.
French scientists say they have discovered the smallest dinosaur egg ever discovered if bird eggs are not included. Because scientists consider birds to be living dinosaurs, bird eggs should also be counted as dinosaur eggs. Researchers said that four miniature dinosaur eggs were laid by the same dinosaur, and two of them contained embryos. These dinosaur eggs were probably the size of a goldfinch, or slightly larger. The body length of a goldfinch is generally about 11 centimeters.