This ancient fish was bigger than a whale shark—and faster than scientists ever imagined (1 Viewer)

[Cold Ethyl]

Scientists have long struggled to explain why bony fishes are so small: The heaviest—the ocean sunfish—is just 2.3 metric tons, but cartilaginous fishes like whale sharks can weigh up to 34 metric tons. Now, a new study of an ancient giant suggests this modern difference is merely an evolutionary accident.
Bony fish, which make up some 95% of all fish species, might be constrained by their metabolism according to one argument. Larger animals generally have to make do with less oxygen per gram of tissue; because bony fish seem to have higher metabolic requirements than sharks, it might simply be impossible for them to grow much larger than the ocean sunfish.
Enter Leedsichthys problematicus. The extinct fish—thought to be the largest on record—lived about 165 million years ago in Europe and South America. It grew to at least 16.5 meters in length and might have weighed 45 metric tons, which means it was larger even than today's whale shark

Realizing modern biologists had left ancient fish out of their equation, scientists decided to calculate L. problematicus's metabolic requirements. They used data from living bony fish as a guide, and they found that it would have not only survived, but thrived: In theory, the giant fish could have cruised along at speeds of 17.8 kilometers per hour while still keeping its tissues adequately oxygenated, they report this month in Palaeontology. For comparison, the speediest living fish probably swim no faster than 30 kilometers per hour.
It's still a mystery why there are no gigantic bony fish today, but metabolically speaking there's no reason why they shouldn't exist, the researchers conclude.

Science | AAAS

www.science.org

 

[ZeroK]

Excellent Post Cold E! By chance, would u have any info on this find?

 

[Ellzibette]

There is a lot about evolution that doesnt fit. When you dig into it, its really fascinating.

 

[hedgerow]

Excellent Post Cold E! By chance, would u have any info on this find?View attachment 683507

Interesting. I didn't realize they even had chalk 153k years ago.

 

[Mudskipper]

Scientists have long struggled to explain why bony fishes are so small: The heaviest—the ocean sunfish—is just 2.3 metric tons, but cartilaginous fishes like whale sharks can weigh up to 34 metric tons. Now, a new study of an ancient giant suggests this modern difference is merely an evolutionary accident.
Bony fish, which make up some 95% of all fish species, might be constrained by their metabolism according to one argument. Larger animals generally have to make do with less oxygen per gram of tissue; because bony fish seem to have higher metabolic requirements than sharks, it might simply be impossible for them to grow much larger than the ocean sunfish.
Enter Leedsichthys problematicus. The extinct fish—thought to be the largest on record—lived about 165 million years ago in Europe and South America. It grew to at least 16.5 meters in length and might have weighed 45 metric tons, which means it was larger even than today's whale shark

Realizing modern biologists had left ancient fish out of their equation, scientists decided to calculate L. problematicus's metabolic requirements. They used data from living bony fish as a guide, and they found that it would have not only survived, but thrived: In theory, the giant fish could have cruised along at speeds of 17.8 kilometers per hour while still keeping its tissues adequately oxygenated, they report this month in Palaeontology. For comparison, the speediest living fish probably swim no faster than 30 kilometers per hour.
It's still a mystery why there are no gigantic bony fish today, but metabolically speaking there's no reason why they shouldn't exist, the researchers conclude.

Science | AAAS

www.science.org

Geez that makes Xiphactinus look like a goldfish - wonder if it was a filter feeder at that size?

There is a lot about evolution that doesnt fit. When you dig into it, its really fascinating.

Bold claims need bold evidence

Excellent Post Cold E! By chance, would u have any info on this find?View attachment 683507

I reckon that's a stretch to conclusively say that's a Homo foot print let alone specifying Homo Sapiens, there were a few different hominins running around still. Would be interesting reading the paper on this and see peer reviews - there must be more than one imprint showing walking gait pattern etc otherwise it could have happened by other means without any bipedal input whatsoever

 

[Kapitän Ghul']

100 million years before what most of us think was the time of dinosaurs. Life is funny.

 

[wiggins]

Scientists have long struggled to explain why bony fishes are so small: The heaviest—the ocean sunfish—is just 2.3 metric tons, but cartilaginous fishes like whale sharks can weigh up to 34 metric tons. Now, a new study of an ancient giant suggests this modern difference is merely an evolutionary accident.
Bony fish, which make up some 95% of all fish species, might be constrained by their metabolism according to one argument. Larger animals generally have to make do with less oxygen per gram of tissue; because bony fish seem to have higher metabolic requirements than sharks, it might simply be impossible for them to grow much larger than the ocean sunfish.
Enter Leedsichthys problematicus. The extinct fish—thought to be the largest on record—lived about 165 million years ago in Europe and South America. It grew to at least 16.5 meters in length and might have weighed 45 metric tons, which means it was larger even than today's whale shark

Realizing modern biologists had left ancient fish out of their equation, scientists decided to calculate L. problematicus's metabolic requirements. They used data from living bony fish as a guide, and they found that it would have not only survived, but thrived: In theory, the giant fish could have cruised along at speeds of 17.8 kilometers per hour while still keeping its tissues adequately oxygenated, they report this month in Palaeontology. For comparison, the speediest living fish probably swim no faster than 30 kilometers per hour.
It's still a mystery why there are no gigantic bony fish today, but metabolically speaking there's no reason why they shouldn't exist, the researchers conclude.

Science | AAAS

www.science.org

O2 at 35% may have helped...