Scientific Classification
















Basilosaurus sp.


Basilosaurus Isis as it appeared in the documentary walking with Beasts 2001

Basilosaurus, sometimes known by its scientific synonym Zeuglodon, is a genus of ancient cetaceans that are thought to have died out 33 million years ago, this was during the time the Eocene epoch ended and the Oligocene started. These primitive beasts look nothing like today’s whales. They were long and serpentine. Basilosaurus is often suggested often as the explanation for sea serpent and lake monster reports. Basilosaurus was one of the largest animals of its time at 66 ft with some non peer reviewed sizes putting it at 70 ft. They are two species (other species from across the world have been assigned, but they turn out to be other Eocene cetaceans). The type species from North america, Basilosaurus cetoides is commonly found in the gulf coast of the Southern US and Basiosaurus isis which is found throughout Northern Africa but the most complete skeletons of the species coming from Egypt. Basiosaurus isis is a very well understood species and its environment and its role in that environment is well understood. These fossils come from the Wadi El Hitan formation, the Wadi El Hitan is now considered a world heritage site, and is one of the most prized fossil locations in Egypt. Fossils from Wadi El Hitan show that B. isis was a predator attacking a smaller whale called durodon and many fish and possibly sharks as seen in the documentary walking with beasts. Basilosaurus cetoides more likely just feed on large sharks and fish.

Basilosaurus was originally named by Harlan due to the fact he thought it was a marine reptile. The name Zeuglodon was recommended later after a geological conference, but due to the fact that only the original scientific describer is the only one who can rename a species, so the name Basilosaurus was stuck. Zeuglodon is preferred by cryptozoologists, as the species was called Zeuglodon for a fair bit of time.

If these primitive whales are still alive, they would certainly fit with the a few select characteristics of basilosaurus, such as a long body. However many sightings are based over outdated overly serpentine designs from the 1950s. any lake monsters and sea serpents present an elongated, serpentine shape, similar to Basilosaurus. In addition, many sea serpents and lake monsters have been reported from northern waters that are thought to be too cold for reptiles such as plesiosaurs or giant snakes, but these same waters would be fine for an aquatic mammal. While this could be the case Basilosaurus has no evidence it contained blubber and in its time it did not need it (although evolving it could be the case, but its not the most likely option)

Sea serpents and lake monsters are also frequently described as having bits of hair (especially a mane) and as swimming with vertical spinal flexure, both characteristics of mammals, not reptiles.

Even though the latest Basilosaurus fossils are around 33.9 million years old, it is not a terrible concept to think it could have survived past that time and into the modern times. Although this can be countered by most skeptics and paleontologists, due to the fact Basilosaurus went extinct during an extinction that would not favor its survival[1] and that fact whale fossils are quite common even having whale fossils up to 10,000 years old the max date that fossil can form.[2]

Basilosaurus probably evolved from mesonychids, a family of hoofed predators, or from very close relatives of the mesonychids. Some of the earliest whales even had rows of tiny hooves along the edges of each flipper (early hoofed animals had larger numbers of hoofed toes than today’s modern ungulates such as cows and horses).

In recent years the animal have become the primary focus of several cryptozoology researchers who theorize that the animal may be responsible for some modern reports of Lake Monsters and Sea Serpents.


Basilosaurus seems to be a better choice then the plesiosaurus, Pliosaurus, Icthyosaurus or Mosasaurus due to the fact its more recent in the fossil record, however the evidence seems to point to the fact, that just like marine reptiles, its most likely not the case. However it is a possibility, just not a very likely one.

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