The text on the card is in Russian, an ancient language similar to the language native to the cave dweller island, although, everyone on the archipelato is practically bilingual (some are trilingual if they have relatives in the Mute tribe), so strong are the connections between the archipelago people. Still, some translation is definitely required, especially because surnames and patronymics no longer exist in the post-ice-age world.
Most Russian surnames symbolize belonging. For example, my surname - Makarova - means "a woman who belongs to Makar" (for a man it would be Makarov, without "a"), like in "Whose relative/servant are you?" - "Makar's" (Makar is an old male name, still used sometimes). After slavery was abolished, lots of surnames for newly freed people had to be invented on the spot (most slaves didn't have them before), so asking "whose person are you" and inventing a new surname based on the answer was often a quick solution to the problem. One of my ancestors had the name Makar.
This poor guy's surname was Sedov. Surnames like this one were created in a similar way but derived from nicknames, not names. Nicknames were widely spread back then. Here's why. Before the 1917 revolution, the church had a strict lists of names for babies, each name tied to a certain date (or several dates), that left parents no choice, so there could be a hundred Ivans in the same village. Nicknames helped address a certain Ivan and not the other and often replaced church-given names in ordinary life.
"Sedoy" means "grey-haired man" (a woman would be "Sedaya"). So its easy to imagine this situation "Whose son are you?" - "Sedoy's" (in Russian: Sedov). Boom! Your surname is Sedov now and your descendants will inherit it.
Patronymics are always derived from the name of the person's father. For example, my patronymic - Andreevna (the male version would be Andreevich) - means that my father's name is Andrey. In the past, patronymics also replaced names in some cases but only for older people. The combination "name + patronymic" is still used to politely address someone important, like a teacher.

Ellie translates the situation as "he was from Sedov family" and "his father's name was Anatoliy" to the other girls to simplify things for now: history lessons can wait until they're done with the caves.