Xenology
xenology - n. 1. The science of foreign/ exotic things. 2. The science of parasites. [from Greek xenos stranger, logos science]
It's a science-fiction trope to have a scientist whose specialty is "xenology" (or "xenobiology," "xenochemistry," etc) whose job is to be the expert at anything that would not be encountered on Earth, and thus exposition for the sake of the reader of this story.
Characters in an RPG will probably have a 'xenology' skill, used for tests involving aliens or off-world artifacts.
Warhammer 40,000
"Xenology" is the title of a Black Library sourcebook, which purports to be an Inquisitor's account of his investigation of a rogue Magos Biologis working in the employment of a Radical Inquisitor Lord (who was in fact a Necron Lord in disguise). Along the way, he publishes the Tech-priest's notes on dissected aliens and xenotechnology.
Many interesting details of alien biology are given, some of which are a little dubious, like toes on a Tau. Other details are just weird, like Eldar having crystalline feces (that ought to hurt) and extremely sensitive ears.
It's unknown why these discrepancies are present. Perhaps the information is intentionally inaccurate as a form of sabotage or Lulz. Perhaps the tech priest was just incompetent and mixed up all his specimens.