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Fossils push animal evolution back 300 million years

Source: newscientist.com

TL;DR

Fossils from 635 million years ago reveal complex animals like sponges and corals evolved far earlier than thought.
These Ediacaran finds in China and Canada push back animal origins by over 300 million years.
The discovery challenges the idea that animals only appeared after the Cambrian explosion 541 million years ago.
It reshapes our timeline of life's complexity on Earth.

The story at a glance

Surprise fossils unearthed in remote rocks are rewriting the dawn of complex life. Researchers from Imperial College London and others report these finds now, upending long-held views on animal evolution.

Key moments & milestones

635 million years ago: Ediacaran period sees earliest evidence of sponges, corals, and worm-like creatures in China's Lantian Formation.
575 million years ago: Similar fossils appear in Canada, showing sustained animal presence.
541 million years ago: Traditional Cambrian explosion marks burst of animal diversity - now seen as a later flourish.
2024: Teams use advanced microscopy to confirm cellular structures in the ancient specimens.

Signature highlights

Dickinsonia - a flat, quilted organism once debated as a lichen - now confirmed as an animal via cholesterol biomarkers.
Sponge embryos preserved in China, with spicules and collar cells matching modern species.
Worm burrows and ctenophore fossils indicate active, mobile life long before skeletons evolved.
Comparative ages:

Period	Key Fossils	Age (millions of years)
Ediacaran	Sponges, corals	635
Cambrian	Diverse phyla	541

Key quotes

"These fossils force us to rethink when and how animals first appeared." - Emily Carlisle at Imperial College London.

"The Ediacaran biota were not failed experiments - they were the roots of animal kingdoms." - Scott Evans at University College London.

Why it matters

This shifts evolutionary timelines, suggesting animals weathered Earth's turbulent Cryogenian ice ages and influenced oxygen levels earlier. It prompts re-examination of ancient rocks worldwide for overlooked signs of complexity. Watch for debates on whether these pioneers survived to seed Cambrian seas - a clue to life's resilience.