The Bible’s assertion that the Genesis patriarchs routinely experienced lifespans of hundreds of years is one of the claims in Scripture most ridiculed by skeptics. Hence, Biblical creationists should be interested in possible scientific corroboration of this claim. Whatever factor or factors were allowing extreme human longevity inthe pre- and immediate post-Flood worlds were likely also affecting the animal kingdom, as well. Hence, it is reasonable to suspect that animal lifespans were also once much greater than they are today. In this light, we examine fossil shark data for possible evidence of extreme longevity. Paleontologists have used allometric relationships and growth rings within shark vertebrae to construct ontogenetic length-versus-age growth curves for both extinct and extant sharks. Growth curves for fossil sharks are generally too short to provide direct evidence that fossil sharks experienced much greater longevity than extant sharks, but they are sufficiently long to show that fossil sharks took longer to mature than comparable extant sharks. Longevity studies of extant animals have repeatedly shown that greater ages at skeletal and/or sexual maturity are positively correlated with greater longevity, as are larger adult body sizes. Hence, the apparent delayed maturation and large adult body sizes of these giant fossil sharks is indirect evidence that they had much greater lifespans than extant sharks. By extension, it is partial scientific corroboration of the extreme human lifespans recorded in the earliest chapters of Genesis.