Discovery Channel's Shark Week 2013 premiered last night with a fake "Megalodon" documentary that left some viewers scratching their heads. "Megalodon: The Monster Shark Lives" is a two-hour mockumentary that opened the 26th annual Shark Week last night. According to Gawker, there was a blink-and-you'll miss it disclaimer that read:

"None of the institutions or agencies that appear in the film are affiliated with it in any way, nor have approved its contents. Though certain events and characters in this film have been dramatized, sightings of "Submarine" continue to this day. Megalodon was a real shark. Legends of giant sharks persist all over the world. There is still debate about what they might be."

Shark Week 2013 asks: is Megalodon still alive?

Basically, Discovery Channel aired a fake hunt for a prehistoric shark that most reputable scientists believe has probably been extinct for more than a million years. This angered some viewers, who took to Twitter to express their disappointment with Shark Week's opening night fallacies.*

Matt Benoit tweeted, "@Discovery should be ashamed @SharkWeek is supposed to be about education, not fabricated stories for #ratings all of #megalodon was fixed."

Ruben R. Diaz tweeted, "Shark Week had a 'documentary' about #megalodon, up next is an in-depth analysis about the very real threat of a #Sharknado."

Justin Denson tweeted, "@SharkWeek Why did you abandon informative, science based programming in favor of Sci-Fi Channel fodder? Shocked Mermaids didn't find Megalodon,"

Some people were confused. Dylan Walsh tweeted, "Shark Week got me convinced that megalodon is real."

Some people tweeted questions at David Shiffman, a marine biologist studying shark conservation, who took to his account @WhySharksMatter to clear the facts.

"As a professional #shark scientist, I can unequivocally state that despite a #SharkWeek documentary, #megalodon is extinct," he tweeted.

"Woke up w/ a #megalodon hangover. @Discovery @sharkweek did nothing to promote science, only promoted fear. Grateful for @WhySharksMatter."

But it wasn't all condemnation for Shark Week 2013.

Nicole St. Onge tweeted, "I think @SharkWeek should just play #Megalodon all week. That's how crazy that is. Loved the kickoff."

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