![]() These sharks' broad, flat, hammer-shaped heads are called cephalofoils, and no other creature in the world has a head quite like it. THEIR HEADS MAY GIVE THEM A HUNTING EDGE. They also argued that today’s modestly-sized bonnethead and winghead sharks independently evolved from big ancestors. What did the earliest hammerheads look like? According to the researchers, these were probably large-bodied animals. The fossil record tells us sharks have existed for at least 420 million years-so if the University of Colorado team is correct, hammerheads are relative newcomers on the world stage. The molecular evidence suggested that the hammerheads started to diversify around 20 million years ago. In 2010, geneticists at the University of Colorado, Boulder compared DNA samples from eight hammerhead species in an attempt to map out the family’s evolutionary history. IT LOOKS LIKE THEY EVOLVED SOMEWHAT RECENTLY. Three hammerhead species have a high risk of extinction: the great hammerhead, which is threatened by the shark fin trade and bycatch (unwanted fish captured as a byproduct of commercial fishing) the winghead ( Eusphyra blochii), whose population is believed to have declined 50 percent in 42 years from overfishing and net entanglement and the scalloped hammerhead ( Sphyrna lewini), which, in 2014, became the first shark to ever receive protection from the U.S. Hammerheads also vary in terms of overall size: The smaller species max out at 3 to 5 feet in length, while the biggest is the great hammerhead ( Sphyrna mokarran), which can be up to 18 feet long and weigh over 1000 pounds (with 10 to 13 feet and 500 pounds being closer to average). Keen-eyed observers can tell most of these guys apart by the slight differences in their skull shapes. Nine belong to the genus Sphyrna (Greek for "hammer"), while the other-an oddball called the winghead shark-is the sole member of its own genus, Eusphyra. ![]() Įxperts have identified 10 living shark species in the hammerhead family (although it’s possible that even more exist). These fish are diverse, they’re weird, and someday they might change the way we fight skin cancer. There were mere inches away from a truly gargantuan great white shark and there was blood in the water.Is there any fish in the world that casts a more distinctive shadow? Divers have little trouble recognizing a hammerhead when they see one. It is remarkable how calm they stayed on the ledge. “I panicked for the guy in green and he’s so chill about it. “I wouldn’t even care about losing the fish, that was awesome.” I would’ve buckled and fell in the water to be dessert for the great white.” **It’s the chemical currency that tells us about the value of our experiences and efforts**. You can start to see why dopamine is so fundamental to the evolution of every species. ![]() I’ll also never forget that incident because when we get a big and unexpected release of dopamine, it leaves and indelible mark on our memory. However, the reward of seeing it breach was greater than the meal we would’ve had. A local great white reminded us that, when they are around, humans eat last. ![]() We wanted tuna for our dinner and we had one on the line… we were expecting a (meal) reward. For the SHOCKING twist□ Hand-lining a HUGE tuna takes an INSANE turn!□□ #fyp #foryou #greatwhiteshark #bigeye #fishtok #sharkencounter #tiktokviral #fishingadventure #heartstopping #mustwatch #sharkfishing #tunafishing #biggamefishing #deepseafishing #fishinglife #Australia #SouthAfrica #Japan #USA #NewZealand #Indonesia #CostaRica #Mexico ![]()
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