Sepulkas were first mentioned by Lem's interstellar traveller Ijon Tichy during his fourteenth voyage.
It is further revealed that the entire Encyclopaedia Cosmica was a hoax — and therefore any speculations about the "pornosphericity" of sepulkas must be discounted.
"[4] A comparison of two recent Russian biographies of Lem (written in 2014 and 2015) notes that neither biographer was able to clarify the nature of sepulkas.
[6] In the film, Tichy acquires a sepulka (an egg-shaped object), but when he tries to board his spaceship (piloted by professor Tarantoga), he is hit by a meteorite, the plague of Enteropia, and at that moment it is revealed that the purchased egg-shaped object stored Tichys's double, which was the standard remedy against the meteorite kills on Enteropia.
It was identified by Alexandr Pavlovich Rasnitsyn and named by his colleague and science-fiction author Kirill Eskov.
[11] In 1972 Russian paleontologist Nina Shevyryova (Нина Семёновна Шевырёва, 1931–1996) named an extinct rodent Sepulkomys eboretus.
[12] "Eboretus" is another bow to Lem: "eboret" is a type of public transport on the planet Enteropia visited by Tichy in his "Fourteenth Voyage".