Mississippi: Basilosaurus and Zygorhiza (state fossils)
Mississippi: Basilosaurus and Zygorhiza (state fossils)
Mississippi has more official fossils than any other state, having two state fossils, the early whales Basilosaurus and Zygorhiza, and also a fossil for its state stone, petrified wood. The early whales lived during the Eocene Epoch, around 45 million years ago, when the coastline of the Gulf of Mexico extended across what is now Mississippi.
Basilosaurus is the larger and better-known of the two state fossils. It had a small head and a narrow body 50 - 80 feet long, giving it the look of a "sea serpent." The first specimen of this whale was found in 1832 along the Ouachita River, and since that time specimens have turned up regularly in Mississippi, Louisiana, and Alabama. Zygorhiza was a smaller whale, reaching only 20 feet, and had a more whale-like body form. The first well-preserved specimens of Zygorhiza were found on the Gulf Coastal Plain in the late 1800s, and a nearly complete skeleton was excavated near Tinsley in 1971.
These early whales were well adapted for a swimming lifestyle but still retained the complex teeth of their ancestors. Their descendants, the modern whales, either have simple conical teeth (dolphins, orcas, sperm whales) or sieve-like baleen plates (grey whales, right whales and most others). Basilosaurus and Zygorhiza may have used their complex teeth both to crush prey like fish and squid, and to strain smaller food items from the water.
These prehistoric whales were honored as twin Mississippi state fossils with Senate Concurrent Resolution No. 557 on March 26, 1981.
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