I took a look at the people added in the list of surnames in the Venjoki project and I found this profile: Tuomas Ollinpoika Pennanen
I'm the one who added him once, but I know for sure I haven't done any research in Finnish archives. This profile must have been merged with another person's profile.
Can I somehow find out former connections to the profile? This man must have been connected to Venjoki before he was merged into a totally different person and someone removed his relatives.