Tut's Dagger: 5 Most Incredible Discoveries of the Week

An ancient, cosmic dagger and a new way of looking at T. rex make the list of the week's intriguing discoveries:

• King Tut's Dagger Just Got More Interesting: King Tut’s dagger is out of this world—or at least it was at some point. Researchers who analyzed the blade say the iron used to make it came from a meteor. And another insight involving linguistics suggests that Egyptians knew full well about the dagger's unusual source material.
• There Was More Than One Alamo: Turns out the site we know as the Alamo in San Antonio wasn't its first iteration. Archeologists now think it was initially founded at a different site in 1718, then moved about a mile away to yet a second one in 1719. Part of the secrets lie under a parking lot.

• Underwater 'Lost City' Is Something Else Entirely: A "lost city" discovered by snorkelers off the Greek island of Zakynthos isn't an underwater metropolis after all. Turns out Mother Nature is responsible for these weird formations, though you might not think that at first glance.
• T. Rex Didn't Look the Way We Thought: The image of a "ferocious-looking" Tyrannosaurus rex with a "permanent smile" of huge protruding teeth is taking a hit thanks to one Canadian paleontologist. Robert Reisz says the T. rex actually had scaly lips covering its teeth—just don't picture Mick Jagger lips.
• Eating Plastic Is Making Young Fish Stupid: Fish are getting hooked on plastic that's making them "smaller, slower, and more stupid," say researchers. The worst part is that they seem to love the stuff—see why researchers liken it to fishy fast food.

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