Explanation

During embryonic development, the lateral mesoderm is divided into two distinct layers by the intra-embryonic coelom 

The intra-embryonic coelom is a fluid-filled cavity within the lateral plate mesoderm.

As the embryo develops, the coelom divides the lateral plate mesoderm into two layers.

• the somatic mesoderm (which lies adjacent to the ectoderm) 
• the splanchnic mesoderm (which lies adjacent to the endoderm). 

This division is crucial for the formation of organs and structures in the developing embryo.