Sujet : Cambrian explosion may have occurred 15 million years earlier than previously thought
De : invalide (at) *nospam* invalid.invalid (Pro Plyd)
Groupes : talk.originsDate : 29. Jun 2025, 20:35:43
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Organisation : Amateur Plyd
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https://phys.org/news/2025-06-cambrian-explosion-million-years-earlier.htmlThe Cambrian explosion was an extraordinary
phenomenon in the evolution of life on the planet
that led to the emergence of many animal phyla and
the diversification of species. During this period,
some 530 million years ago, most of the basic body
plans of organisms that have survived to the present
day emerged. However, this great explosion of life
that changed the evolutionary landscape on Earth
may have occurred millions of years earlier than
previously thought, a hypothesis now reinforced in
a study published in the journal Geology.
This is a main conclusion of a new study that
analyses the body profiles of organisms—symmetry,
segmented bodies, exoskeletons, etc.—from around
545 million years ago by analyzing trace fossils,
which are the fossilized marks in rocks and sediments
left by the activity of organisms in the past.
...
https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G53332.1/655874/Quantitative-decoding-of-Ediacaran-locomotoryQuantitative decoding of Ediacaran locomotory trace
fossil morphologies: Evidence for the emergence of
slender anterior-posterior body profiles