Mined from: White River Formation, South Dakota, USA

Era: Cenozoic

Geological Age:  34 to 23 Million Years Old

Description: The White River Formation in South Dakota, USA, is renowned for its rich fossil record, particularly of mammal bones from the Oligocene epoch, approximately 34 to 23 million years ago. The landscapes of Oligocene South Dakota included open woodlands, grasslands, and scattered forests dominated by coniferous trees. These environments supported a diverse array of early mammals. Commonly found fossilized mammals from this locality include:

Oreodonts: a diverse group of herbivorous mammals that were abundant in North America during the Oligocene epoch. Species such as Merycoidodon and Leptauchenia are among the most commonly found fossils in the White River Formation. Oreodonts had unique teeth adapted for grinding tough vegetation, and they occupied various ecological niches within ancient ecosystems. Their ecological versatility and population density likely contributed to their highly frequent representation in the White River formation (the majority of the specimens from this lot are oreodont bones).

Perissodactyls: early ancestors of modern horses (Mesohippus and Miohippus) and rhinoceroses (Subhyracodon) have been identified in the White River Formation. These perissodactyls were adapted to browsing on leaves and vegetation in the ancient woodlands and grasslands of Oligocene North America.

Carnivores and Creodonts: early carnivorous mammals, including small dogs (Hesperocyon) and creodonts (an extinct group of carnivorous mammals), have also been uncovered in the White River Formation. These predators played important roles in the Oligocene ecosystems, feeding on smaller mammals and other prey.

Approximate Size of 1 piece: 3cm x 3.5cm x 2cm
Approximate Weight of 1 piece: 30g

Quantity: 1pc

We do our best to buy quality products- although not every rock is the same. If you choose to purchase the "staff pick option", we will select the best of the batch for you. Otherwise, it will be at random from the larger batch we have in stock.