Is it just Shark Week, or did thresher sharks get smarter?

Divers off the coast of Cebu, an island in the Philippines, called Simon Oliver when they noticed sharks exhibiting some strange behavior.

Oliver, an expert on these sharks since he began studying them in 2005, dropped everything to see what all the fuss was about. Apparently they were using their tails to hunt—strange behavior because it was thought that only smart mammals like dolphins and whales practiced tactical use of the tail fin.

Equipped with underwater camera equipment, the Thresher Shark Research and Conservation Project set out to film the new shark activity. They captured footage of 25 hunting events, then went back to the lab to analyze the videos.

The researchers found that the sharks hunt schooling sardines using a four-step procedure. This way, instead of collecting just one fish in their mouth per hunting event, they first stun the fish to eat an average of 3.5 sardines.

Thresher sharks’ tails comprise about 50% of their total length, which is particularly impressive for the 20-foot, 1,000-pound individuals. A sardine lucky enough to survive its initial fear would witness an incredible “tail-slap,” only to die or become stunned shortly after.

First the shark prepares. This preparatory lunge lasts longer than the other three phases, allowing the shark to perform some advanced physics calculations in order to determine tail velocity needed based on mass… Just kidding, they aren’t that smart! The shark then strikes, recovers briefly, and collects its prey.

“This extraordinary story highlights the diversity of shark hunting strategies in an ocean where top predators are forced to adapt to the complex evasion behaviors of their ever declining prey,” said Oliver.

These sharks had been studied previously, but Oliver thinks that lack of food has caused the sharks to hunt near the surface, finally giving humans a glimpse of their unique hunting techniques.

The footage is pretty incredible, and you can check it out here!

Alyssa Keimach is an astronomy and astrophysics student at the University of Michigan and interns for the Morrison Planetarium.

Thirty years ago, a farmer discovered an adult male mastodon skeleton in Washington state. At the time, archeologist Carl Gustafson excavated the fossil and found some peculiar things about it. Ed Yong explains in the Guardian:

[He] noticed a pointed object embedded in its rib. Gustafson took a fuzzy x-ray and interpreted the object as a projectile point made of bone or antler… By dating organic matter around the fossil, he estimated that it was about 14,000 years old.

Other researchers challenged the man-made instrument and date—one reason was that it pre-dated the Clovis culture by about 1,000 years. Clovis is the name given to the distinctive tools made by people starting around 13,000 years ago. Gustafson’s finding would have rewritten the history of people on our continent.

Technology has changed quite a bit since the discovery of the mastodon bone thirty years ago. Enter Michael Waters of Texas A&M. As we described in an article about his research last spring, he’s not afraid to rewrite history. Waters contacted Gustafson about performing new tests on the rib with the bone point.

Waters modern tests confirmed Gustafson’s suspicions. New radiocarbon dates confirmed that the site was 13,800 years old. High resolution CT scanning and three-dimensional modeling confirmed that the embedded bone was a spear point, and DNA and bone protein analysis showed that the bone point was made of—get this—mastodon bone.

“The evidence from the site shows that people were hunting mastodons with bone weapons before the Clovis stone spear point,” says Waters.

In addition, the new evidence supports extinction theories of large mammals at the end of the last Ice Age. During the last cold period, herds of mammoth, mastodon, camels, horses and other animals roamed Texas and North America. At the end of the Ice Age, these animals became extinct.

“While these animals were stressed by the changing climate and vegetation patterns at the end of the Ice Age, it is now clear from sites like [this one] that humans were also hunting these animals and may have been a factor in their demise,” Waters adds.

Timing is indeed everything. The current research was published last week in the journal Science.

Image courtesy of Center for the Study of the First Americans, Texas A&M University