Scans of a subset of its roughly a whole bunch of vertebrae — some the scale of grapefruits — confirmed the shark had died on the age of 46. The researchers estimated the meg’s life expectancy to be round 88 to 100 years, implying that their specimen had been roughly “middle-aged,” Dr. Shimada mentioned. In addition they back-calculated the shark’s measurement by its earliest years, and located it might need been greater than six and a half ft lengthy when it was born.
“That’s a extremely large child,” mentioned Mr. Cooper, who was not concerned within the examine.
To succeed in such a staggering measurement, burgeoning megs could have snacked on one another whereas nonetheless within the womb, Dr. Shimada mentioned. Most sharks hatch from eggs inside their moms’ our bodies, then are birthed as dwell younger. However the pups of some species don’t take kindly to roommates: As soon as hatched, they are going to start to casually devour their unhatched siblings, which helps them beef up earlier than being born.
“It’s this large, calorie-dense, nutritious meal that may assist these embryos get greater, quicker,” mentioned Allison Bronson, who research the evolution of fish at Humboldt State College in Arcata, Calif., however wasn’t concerned within the examine.
With that a lot heft in tow, mini-megs might need emerged able to duke it out with potential predators, or not less than dwarf a very good variety of them in measurement. A voracious urge for food, coupled with warm-bloodedness, might need helped them snarf down loads of prey, permitting the juvenile terrors to bulk up much more.
Mr. Cooper mentioned the examine offered essential knowledge on a poorly understood animal. However he famous that some calculations it used have been primarily based on knowledge gathered within the Nineties, when researchers relied extra closely on nice white sharks to estimate features of megalodon anatomy. Drawing too shut a comparability between the 2 animals, he mentioned, may result “in underestimations in some particular physique dimensions.”
It’s additionally laborious to understand how consultant this one particular person megalodon was of its species, Dr. Bronson mentioned. “There’s loads of variation in fishes,” she mentioned. “Even fish of the identical age, similar species, can develop at actually totally different charges and attain actually totally different sizes.”
Researchers can’t understand how troublesome carrying and birthing a six-foot-plus pup might need been for megalo-moms. However “proportionally, whereas that child is basically large, so is the grownup,” Mr. Cooper mentioned. At most measurement, some megalodons might need spanned almost the size of a bowling lane — loads of house to deal with even a basketball-player-size embryo.