Dinosaur eggshell study confirms biogenic origin of secondary eggshell units
The calcitic layers of the eggshells of archosaurs (including crocodilians and birds) and turtles are composed of distinctive crystalline structures known as eggshell units. Those growing from the shell membrane are called primary eggshell units (PEUs), while those forming within the calcitic layer are called secondary eggshell units (SEUs). Although rare in modern bird eggs, SEUs are common in dinosaur eggs. Due to the lack of in-depth research on this structure, however, scientists are uncertain whether they are biogenic or abiogenic in origin.
The calcitic layers of the eggshells of archosaurs (including crocodilians and birds) and turtles are composed of distinctive crystalline structures known as eggshell units. Those growing from the shell membrane are called primary eggshell units (PEUs), while those forming within the calcitic layer are called secondary eggshell units (SEUs). Although rare in modern bird eggs, SEUs are common in dinosaur eggs. Due to the lack of in-depth research on this structure, however, scientists are uncertain whether they are biogenic or abiogenic in origin.
