1. Plural of gastrula; early embryonic stages in animal development characterized by the formation of three primary germ layers (ectoderm, mesoderm, and endoderm).
Usage: biology; developmental biology; technical

Examples

• During embryonic development, gastrulas form after the blastula stage.
• The gastrulas of different animal species show remarkable similarities in their basic structure.
• Scientists study gastrulas to understand how tissues and organs begin to differentiate.
• Under the microscope, gastrulas display the characteristic three-layered organization.
• The formation of gastrulas is a critical milestone in animal development.