DTG, remember that these yuties are waaayyy bigger than a real yutyrannus, and bigger creatures usually have longer lifespans(humans and koi carp are exceptions, but remember for their families they are pretty big species),

a real yutyrannus (nine meters long) could likely live twenty five years if it wasn't eaten as a chick(and, yes, I do refer to baby yuties as chicks)

A Yutyrannus saevus, the ARK yuty, is. . . Maybe. . . Eighteen meters or more, if we look at the lifespans of similar sized creatures, for instance, bowhead whales,

the yuties could have a lifespan of about one hundred and fifty years taking into account the fast growth speed, although judging by the fact seasnake said Blicket and Wildew were only juvenile/adolescent a few years later,

They could easily live for. . . Oh. . . Three hundred years, give or take about a hundred depending on their luck

~Poecilotheria metallica,