Fossil Ginkgo leaf | Ginkgo cranei | North Dakota

Ginkgo cranei Paleocene Sentinel Butte Formation Morton County, North Dakota Matrix measures approx: 3.5" x 3.25" Ginkgo leaf measures approx: 2" x 1.75" Ginkgo cranei is an extinct species of ginkgo known from fossil leaves, particularly from the Late Cretaceous through Paleogene. Its leaves closely resemble those of the modern ginkgo (Ginkgo biloba). Typical fossil leaves are: Shape: Fan-shaped to broadly wedge-shaped, with a rounded or slightly truncate outer margin. Size: Generally a few centimeters across, although considerable variation occurs. Leaf margin: The outer edge is often irregularly lobed or deeply divided, producing two or more broad lobes. Venation: Characteristically dichotomous—veins repeatedly fork into two branches as they extend toward the margin. The veins are usually fine, closely spaced, and radiate outward from the base. Base: The leaf commonly narrows toward a slender petiole (leaf stalk). Texture/preservation: Fossil specimens are typically preserved as impressions or carbonized compressions, with the fan outline and radiating venation clearly visible when preservation is good. Overall appearance: A fossil G. adiantoides leaf looks much like a small, ancient version of a modern ginkgo leaf, but fossil specimens can show substantial variation in the degree of lobing and leaf shape.