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BASILOSAUR (PRIMITIVE WHALE) FOSSILS FOR SALE
What Did Basilosaurs Look Like?
Basilosaurs were long-bodied organisms that had a tails like those of modern whales: they had horizontal flukes that moved up and down. Their heads, however, more resembled land animals with a rostral structure (nose) in relative proportion to the rest of the skull. Modern whales have elongated jaws and rostral structures, called a telescoping skull.
An artist's rendering of a basilosaur. Drawing by Pavel Riha. GNU Free Documentation License
Basilosaur teeth, unlike modern whales, resemble the teeth of land carnivores more than the teeth of modern whales. They had different kinds of teeth in different areas of the jaw, including incisors, canines, and molars. Modern toothed whales have conical teeth throughout their jaws.
A mounted Basilosaurus isis skeleton at the Nantes Natural History Museum.
Basilosaurs retained all four limbs, but their rear legs were rudimentary and their function if any is not clearly understood. The front legs were modified into flippers but retained a functional elbow.
Basilosaurs ranged in size from 13-66 feet (4-20 meters) and likely would have weighed up to fifteen tons.
When Did Basilosaurs Live?
Basilosaurs first appeared in the Late Eocene, about 41 million years ago. They are descended from land-dwelling mammals like the amphibious Pakicetus, widely held to be a basal whale, and Ambulocetus, the transitional organism between land-dwelling creatures and whales.
Basilosaurs disappeared about 33.9 million years ago around the time of the Eocene-Oligocene extinction. This extinction event is attributed to volcanic activity, meteor impact, or climate change that lowered the temperature of the oceans.
Where Are Basilosaur Fossils Found?
Basilosaur fossils have been found on every continent including Antarctica. The first fossils were found on the US Gulf Coast. The most complete skeleton was found in Wadi El Hitan (Valley of the Whales) in western Egypt. Bartonian-aged deposits in the south of England and in New Zealand have also produced basilosaur fossils.
What Are Basilosaurs' Closest Living Relatives?
Though they are related to modern whales, basilosaurs have no living relatives. Both basilosaurs and modern whales are of the order Cetacea, but they are from different families.
Other Basilosaur Facts