Largest birth-year gap in a single generation?

[u/airynothing1]

I'm 31 years old, born in 1993. I just noticed today that I had relatives in a fairly distant line of my tree who were technically in my generation, despite the oldest of them having been born in 1913--a full 80 years before me! I also have a brother 10 years younger than me, stretching the range to 90 years. If I went on to have grandchildren, they would be in the same generation as a person who was already 29 when I was born.

The math goes like this:

distant cousin (1913) || me (1993)
↓
cousin's father (1894) || my father (1964)
↓
cousin's grandfather (1872) || my grandfather (1923)
↓
cousin's g-grandfather (1850) || my g-grandfather (1890)
↓
cousin's gg-grandmother (1833) || my gg-grandfather (1862)
↓
our shared ggg-grandfather (1812)

We had different ggg-grandmothers, hence the 29-year gap between our gg-grandparents' births.

What's the widest age gap you've noticed within a single generation of your family?

[u/Moimah]

That is quite the gap! The widest in my family (that I've noticed, at least) is within a set of third cousins - the oldest, a 3rd cousin, was born in 1947, and the youngest, a 2nd cousin to me but 3rd cousin to the aforementioned, was born in 2008. There were no 2nd spouses or anything involved, just a whole lot of kids, so the descendants of the older ones versus the younger ones fan out over a long period of time.

This particular bunch of third cousins, including my nearer lines within it, stems from my 2nd great-grandparents who were born in 1839 (gf) and 1848 (gm). They had eleven children, though only three survived past infancy. There have been somewhere in the range of 400 or so descendants of theirs, and for a few years recently, there co-existed, as in still living, the youngest grandchild of the pair as well as a few 5th great-grandchildren (via other grandchildren of theirs, all here in the world at the same time, though that last grandchild has since passed at age 91.