6.3" Paleocene Fossil Fruit & Leaf Association - North Dakota

Paleocene Fossil Fruit & Leaf Association - North Dakota #96954

This is a beautiful association of a fossil infructescence (fruit aggregation) with nutlets of the species Palaeocarpinus dakotensis, a fossil fruit from the Juglandaceae (Walnut) family of the species Cyclocarya brownii and a Gingko leaf (Ginkgo adiantoides) that was collected from the Sentinel Butte Formation of North Dakota. The fossils are finely detailed and the light preservation contrasts well against the dark orangish-brown rock.

It comes with an acrylic display stand.

During this time in the Paleocene epoch, the Ginkgo genus was only represented by a single polymorphic species, formerly described as Ginkgo adiantoides. In 2012, the taxon Ginkgo cranei was assigned in place of Ginkgo adiantoides. This species was distributed in much of the northern regions of North America, which had a hot, humid climate at the time. Its leaves were virtually indistinguishable from modern-day Ginkgo biloba. These species of Ginkgo went extinct approximately 7 million years ago.

The Juglandaceae (walnuts, hickories, pecans) has one of the best-documented fossil records in the Northern Hemisphere. The oldest modern genus, Cyclocarya, today restricted to China, first appears in the late Paleocene (57 ma) of North Dakota, USA. Unlike walnuts and pecans that produce edible fruits dispersed by mammals, Cyclocarya fruits are small nutlets surrounded by a prominent circular wing, and are thought to be wind- or water-dispersed. Because Cyclocarya fruits are winged, they might be assumed to be wind-disperse, but their radial symmetry does not have the aerodynamic qualities typical of wind-dispersed fruits, and may have been dispersed by water.

A paper describing these fruits in depth is linked below.

Cyclocarya brownii from the Paleocene of North Dakota, USA