The family trees of passengers Isaac Allerton, Mary Norris Allerton, Mary Allerton, and Degory Priest are fairly well documented, and I've added their parents' names/dates to hubby's family tree. Above, the entry for Isaac Allerton's father Edward and his descendants, dates and all, in a timeline chart created using RootsMagic 7 genealogy software.
Next, I scrolled down the timeline looking for Mayflower ancestors and their parents to see who's earliest. Even though Edward Allerton was born in 1555, he's not the oldest ancestor in hubby's Mayflower branch. Edward Allerton's granddaughter, Mayflower passenger Mary Allerton, later married Thomas Cushman of the Fortune. So the earliest ancestor from that line is actually Thomas Couchman, b. 1538.
Now to my family tree. The oldest ancestor I can name and date on my mother's side is my great-great-great grandfather, Yosef Moshe Kunstler, who died in NagyBereg, Hungary (now known as Berehi, Ukraine) on June 13, 1854. My wonderful cousin B visited the cemetery and photographed the headstone 20 years ago. According to the headstone, Yosef's father's name was Hillel. That's where the trail ends.
On my father's side, the oldest ancestor I can name and date is my great-great grandma Rachel Shuham Jacobs, born about 1845 in Plunge, Lithuania. She married young, was widowed, and came to New York City with her grown daughter and son in the late 1880s. Rachel died in New York City on December 8, 1915. Her death cert shows her parents as Moses Shuham and Sarah Levin, but unfortunately, I have no other info on them.
Thank you to Amy Johnson Crow for this week's #52Ancestors prompt, which is "Oldest."