After some general comments on the concept of asphaltene, outstanding problems relating to the molecular structure of Athabasca asphaltene are discussed in light of new results on aromaticattached appendages derived from ruthenium-ions-catalyzed oxidation (RICO). Detected were homologous series of R-branched C 1 -C 4 n-alkyl side chains up to C 30 -C 40 in an aggregate amount of ∼10% of the n-alkyl side chains, C 15 -C 20 regular isoprenoids, C 20 -C 28 cheilanthanes, C 27 -C 32 hopanes, C 27 -C 29 steranes, C 21 -C 24 pregnanes, and a number of branched hydrocarbons giving hydroxy carboxylic acids. The nature and distribution of these aromatic-attached biomarkers are similar but not identical to those reported to be attached to the asphaltene via a sulfide bridge. They may have originated from secondary biotic sources and became incorporated into the asphaltene via a Friedel-Crafts-type reaction. Additional, previously not considered reactions in the RICO of asphaltene are described, and aspects of the analytical procedures are reviewed. Also, a new protocol minimizing losses due to separations and volatility is discussed. Further structural elements of the asphaltene molecule were identified in the polar fraction of the asphaltene pyrolysis oil, including alkylpyridines and -quinolines, n-alkanoic/alkenoic acids, n-alkylamides (tentative), and n-alcohols. All straight-chain species were dominated by even carbon members. It is shown that contrary to recent erroneous suggestions in the literature, pericondensed aromatic units play a very minor role in the molecular structure of petroleum asphaltene.