Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
Friis initially specialized in lignite, or brown coal, a precursor of black coal that forms from decaying vegetation.
Source: https://www.newyorker.com/science/elements/the-fossil-flowers-that-rewrote-the-history-of-life