author(s)
Asmita Ray, Nupur Pal, Rojina Khatun, Sudeshna Sengupta and Malavika Bhattacharya

abstract
Early jawless vertebrates, both extinct and extant, exhibited unique defense strategies to survive in their environment. Fossil records reveal morphological and sensory adaptations in extinct jawless vertebrates, while extant vertebrates like lampreys and hagfish have more complex cellular and molecular defense mechanisms, including antigen-specific VLRs. Comparing defense systems provides a deeper understanding of immune evolution.