[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Jurassic fern...



Not dino but kinda cool.

http://www.newscientist.com/article/dn25269-lava-fossilised-this-jurassic-fern-down-to-its-cells.html

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" [...]


http://www.sciencemag.org/content/343/6177/1376
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.