"Animals of the Past" by Frederic Lucas explores the fascinating history of vertebrate animals that have vanished from our planet, relying solely on fossil records for evidence of their existence. Written in 1901, this work delves into the concept of extinction, a term that only came into scientific use in the late 18th century, highlighting humanity's evolving understanding of life and loss. The book's focus on the diverse range of vertebrates, from fish to mammals, underscores the fragility of existence and the profound impact of extinction on ecosystems. Its themes of loss and the impermanence of life remain relevant today, reminding us of the importance of conservation and the delicate balance of our natural world.