Wiktionary
n. an ancestor that two or more descendants have in common
Usage examples of "common ancestor".
We may err in this respect in regard to single points of structure, but when several characters, let them be ever so trifling, occur together throughout a large group of beings having different habits, we may feel almost sure, on the theory of descent, that these characters have been inherited from a common ancestor.
But then, we dukes are all related to one another through our common ancestor the Emperor Wen.
The early Roman law only recognized as relatives those who would have been members of the same patriarchal family, and under the same patriarchal authority, had the common ancestor survived.
We don't know exactly how long ago the common ancestor of cows and peas lived, but fossil evidence suggests that it was somewhere between 1,000 and 2,000 million years ago.
Put together a bird and a crocodile, and you can glimpse the genome of their common ancestor, a pre-dinosaur reptile from around two hundred and fifty million years ago.
What does seem possible, however, is that their similarities may be the remnants of a shared legacy received from a common ancestor.
According to the Satapatha Brahmana, Prajapati is their common ancestor.
It is possible that we two Mixtlis could have sat down and traced our lineage back to a common ancestor, but our divergent development had moved us far apart in more than distance.
The original system for the common ancestor of all monkeys and apes was probably promiscuous mating.