xenopaleontology

J. Q. R. Forster, professor of xenopaleontology and xenoarchaeology at King's College, London, was engrossed in a leather-bound volume from a shelf of 19th-century classics when Blake and the commander entered the library.

1990, Paul Preuss, The Medusa Encounter, Avon Books, →ISBN, page 122

I would vehemently hope that in some far-future day a real, honest-to-goodness human geology/xenopaleontology crew is sent to Mars and that it sets down in that same area and seriously examines some of these things up close and^([sic]) great detail.

2004 March 9, Herb Schaltegger, “Re: "Avoiding the 'F word' on Mars -- F*SSIL" -- Oberg”, in alt.alien.visitors (Usenet)

When it had left the system, the tool-users were in the middle of a spirited attempt to wipe themselves out, which led the frigate to one hypothesis that the biological material the freighter was carrying had been some sort of xenopalaeontology expedition to preserve the species; […]

2014, Gavin Deas, Empires: Extraction, Hachette UK, →ISBN, page 26