How did Lamarck contribute to the study of invertebrates?

Jean-Baptiste Lamarck made foundational contributions to the study of invertebrates, a field he significantly shaped during his tenure as a professor at the National Museum of Natural History.1

Appointed in 1793 to oversee the study of "insects, worms, and microscopic animals," Lamarck took on the task of classifying this vast and previously poorly analyzed portion of the animal kingdom. His primary contributions include:1

• Terminology: He coined the term invertebrate to describe animals lacking a backbone, effectively defining the group as a distinct area of scientific study.1
• Systematic Classification: He authored the comprehensive multivolume work Histoire naturelle des animaux sans vertèbres (1815–22), which established a systematic approach to classifying these organisms.2
• Paleontology: Lamarck is recognized as a founder of invertebrate paleontology, applying his systematic rigor to the study of fossilized invertebrates.2

Beyond his specific work on invertebrates, Lamarck is remembered as a pioneering zoology systematist and an early evolutionary theorist who sought to organize all life into a natural system of increasing complexity.2