A collection of images, diagrams, sketches and research surveys believed to be “the world’s largest open access digital archive dedicated to life on Earth,” the Biodiversity Heritage Library is comprised of over 55 million pages of literature. The library (with ephemera dating back to the 15th century) has made over 150,000 illustrations from their collection available for free, high-resolution download. There are also a number of tools available, like “search features to find species by taxonomy and an option to monitor online conversations related to books and articles.” The library offers an immense look into history, art, nature (and all the ways they combine) for those looking to dive into the natural world. See a few of the illustrations at Colossal.
Biodiversity Heritage Library’s Immense Free Image Archive