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Not dino but kinda cool.
Lava fossilised this Jurassic fern down to its cells
One hundred and eighty million years ago, this Jurassic fern was minding
its own business when it was suddenly engulfed by a lava flow. The plant
was almost instantly fossilised, preserving it in incredible detail –
right down to its individual chromosomes in various stages of cell division.
The fern is very similar to a living species: the cinnamon fern,
Osmundastrum cinnamomeum. The similarity of the cinnamon fern to the
fossil supports the idea that is a "living fossil" [...]
Fossilized Nuclei and Chromosomes Reveal 180 Million Years of Genomic
Stasis in Royal Ferns
Rapidly permineralized fossils can provide exceptional insights into the
evolution of life over geological time. Here, we present an exquisitely
preserved, calcified stem of a royal fern (Osmundaceae) from Early
Jurassic lahar deposits of Sweden in which authigenic mineral
precipitation from hydrothermal brines occurred so rapidly that it
preserved cytoplasm, cytosol granules, nuclei, and even chromosomes in
various stages of cell division. Morphometric parameters of interphase
nuclei match those of extant Osmundaceae, indicating that the genome
size of these reputed “living fossils” has remained unchanged over at
least 180 million years—a paramount example of evolutionary stasis.