Osmundastrum pulchellum

Extinct species of fern

Osmundastrum pulchellum is an extinct species of Osmundastrum, leptosporangiate ferns in the family Osmundaceae from the lower Jurassic (Pliensbachian-Toarcian?) Djupadal Formation of Southern Sweden. It remained unstudied for 40 years. It is one of the most exceptional fossil ferns ever found, preserving intact calcified tissue with DNA and cells. Its exceptional preservation has allowed the study of the DNA relationships with extant Osmundaceae ferns, proving a 180-million-year genomic stasis. It has also preserved its biotic interactions and even ongoing mitosis.

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