6.25x8.25" thin artboard has intricately detailed pen and ink illustration by Krenkel showing a native wearing animal skins hunting duck-billed dinosaurs with bow and arrows. Krenkel has signed his initials in lower left-hand corner and added "At The Earth's Core" notation at bottom. In the early 1960s, Ace Books revived the works of Tarzan creator Edgar Rice Burroughs, the first published being "At The Earth's Core." Krenkel created the cover art as well as a frontispiece. We are unsure if this is the art for this frontispiece or if this piece of art by Krenkel was unpublished. N. Mint and ready for display.