Posts Tagged ‘extinct baleen whales’

Carcharodon Megalodon is NOT still Extant. Shame on the Discovery Channel.

August 9, 2013

The Discovery Channel began its annual Shark Week with a 2 hour program about an extinct species of shark, Carcharodon megalodon (or Carchocles megalodon–scientists dispute the classification).  The programming executives care more about ratings than scientific accuracy because they chose to run a phony sensationalist documentary rather than a show based on fact.  It was an embarrassing hoax.  Two supposed marine biologists claimed they had evidence that megalodon was still extant and had bitten a yacht in half off the coast of South Africa in April 2013.  All the evidence they disclosed had alternate and more likely explanations.  For example they showed a photograph of a beached whale that supposedly had its tail bitten off by a megalodon.  They failed to consider that a ship’s propeller could have done the exact same damage.  While I was watching this fake documentary,  I noticed the so-called scientist didn’t act like a scientist.  He proposed killing the shark to prevent another attack.  The recent supposed attack was a rare anomaly–another attack seemed unlikely.  Moreover, I doubt a scientist would propose killing an unknown, possibly rare and endangered species.  The producers of this documentary  staged a dramatic ending.  The team’s scientific vessel dragged a big mock whale behind them littered by a massive bombardment of chum in order to attract a megalodon.  A scientist in a shark cage tagged the supposed megalodon with a tracking device, they all barely survived with their lives, and they then watched the sonar image of the shark carry the tracking device to crush depth where the device was destroyed–a convenient explanation for why they can’t locate it again.

The 2 supposed marine biologists who conducted this study expedition, Collin Drake and Madelyn Joubert, are unknown.  They are not employed by any university and probably are an actor and actress and are not scientists.  I also could find no evidence of a yacht sinking off the South African coast with all hands lost in April 2013.  Shame on the Discovery Channel for misleading the public.  I’m sure there are millions of people out there now who think megalodon is still extant.  It’s not–the evidence strongly suggests it has been extinct for at least 2 million years.

Jawbone of a megalodon compared to the jawbone of a great white shark.  The dispute over the scientific name stems from a controversy over whether megalodon is closely related enough to the great white shark to be considered in the same genus–Carcharodon.  Scientists who think it is not closely related put it in the genus Carchocles.  There probably isn’t enough evidence to determine who is correct.  A DNA test is required but megalodon’s fossils are too old and no longer hold DNA.

Megalodon was one of the most awesome predators to ever live on earth.  It first evolved 18 million years ago as a shark that specialized in feeding upon whales.  Its teeth were specially adapted for biting off hard bony whale flippers, a brutal action that would have quickly disabled the leviathons.  By contrast, great white sharks attack the soft body parts of their prey.  Megalodon was large, growing to 60 feet long and likely preyed upon dugongs, sea turtles, and fish as well as whales and dolphins.

Artist’s rendition of megalodon about to attack a whale.

The heyday of megalodon was the mid to late Miocene, an era when both the oceans and the continents hosted a greater diversity of life than later eras.  During this time period a tropical ocean current revolved between North and South America.  The shallow sea located between the 2 continents was a calving ground for many more species of whales than live on earth today, and it was also a nursing ground for sharks, fish, and invertebrates.  There were 20 genera of baleen whales living in the oceans then compared to just 6 genera today.  An extinct species of sperm whale, Leviathon mellvillei , like megalodon, specialized in feeding upon baleen whales.  Unlike the extant species of sperm whale, Physeter macrocephalus, which specializes in sucking down squid, Leviathon mellvillei had upper teeth built for shearing off whale fins.

A tropical current used to flow between North and South America.  When the landbridge emerged to join the 2 continents, this tropical current and migratory pathway shut down, causing a massive number of marine extinctions, including megalodon.

Megalodon began declining during the Pliocene about 3 million years ago when a landbridge gradually emerged connecting North and South America.  This landbridge caused a massive number of marine extinctions.  The landbridge itself replaced the shallow seas that served as a nursery  for whales and fish, but more importantly it blocked tropical whale migrations and the ancient ocean currents that had existed as part of the marine ecosystem for millions of years.  All the tropical baleen whale species that migrated between North and South America became extinct.  Many fish and saltwater snail species also couldn’t survive the change in oceanic currents.  All surviving species of baleen whales follow circumpolar migration routes.  Because megalodon was a warm water species, there were no whales to feed upon when the remaining species of whales migrated to arctic or antarctic waters.  That’s probably why megalodon became extinct.  There is no evidence megalodon still lives, despite the Discovery Channel’s disgraceful fake documentary.