Although mammals arose in the Late Triassic Period and thus had been around as long as the dinosaurs, dinosaurs had dominated virtually every ecological niche possible for large animals. This limited mammalian diversity. After the demise of the dinosaurs, mammals now took advantage of these openings.

The mammals which appeared in the Oligocene Epoch were different, and somehow more modern, than their predecessors. For the first time, it was possible to discern most modern groups. Fossil mammals from the Oligocene Age actually resemble their present day counterparts.

Paleontologists and zoologists, both amateur and professional, may easily recognize these fossils as cats, dogs, camels, horses, rhinoceroses, rabbits, squirrels and mice. The trained eye may also note the presence of peccaries, ruminants, marsupials, hippopotamoids (anthracotheres), tapirs, mustelids, bears and raccoons. Present, but poorly represented, were bats and primates. In addition to these forms, there were some groups which are now extinct. These included the carnivorous creodonts, rodent-sized multituberculates, entelodonts (giant pigs) and pantolestids. Some very common Oligocene mammals were the oreodonts.

Reptiles & Amphibians

Cast fossil replicas of crocodilians, plesiosaurs, turtles, snakes, and various other marine critters.


Fossils and cast fossil replicas of shark teeth and ancient fish.


Various invertebrate fossils and cast invertebrate fossil replicas.

Plants & Amber

Plants are multicellular organisms which produce their own food through a process called photosynthesis. The first fossil plants and fungi appear in the fossil record about 480 MYA, although scientific data retrieved through molecular and protein evaluations indicate they have been around much longer. Aqueous plants may have been present 1000 MYA, colonizing the land about 700 MYA, while the first flowering plants occur about 140 MYA. Plant fossils include roots, wood, bark, leaves, seeds, fruit, pollen, spores, phytoliths and amber. These fossils are important, both for the information they give us about Earth’s past, and for their beauty.