The earliest animal?
Origin 890 to 480 million years ago. Perplexity summary below.
Aimed at schoolchildren
Sponges are pumps!
When did sponges arise?
The proposed range of time for the origin of sponges spans from approximately 890 million years ago to around 480 million years ago. Key points include:
Some fossil evidence suggests sponges could date back as far as 890 million years ago, based on fossilized remains found in ancient rocks that may represent sponges, pushing the origin into the mid-Neoproterozoic era (Pre-Cambrian)
Molecular clock analyses and genetic evidence also support an origin during the Tonian to Cryogenian periods (about 600 to 800 million years ago), roughly corresponding to the Ediacaran period or earlier
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Confirmed fossil evidence of sponges with good preservation exists from the late Ediacaran period (around 600 million years ago)
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Some research narrows the window for the emergence of crown-group sponges (those leading to modern sponges with siliceous spicules) to about 548 to 517 million years ago, within the Cambrian or just before
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Biomarker molecules attributed to sponges have been found in rocks around 640 million years old, providing indirect evidence of their early presence
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Traditionally, some scientists placed the origin of sponges as late as the Cambrian period (541-485 million years ago), but increasing evidence supports significantly earlier origins
Overall, the likely span for sponge origins is roughly from 890 million years ago (oldest suggested fossils) through the Ediacaran (600-630 million years ago), and at least by the early Cambrian (around 540 million years ago) when sponges are more definitively fossilized.
This wide range reflects challenges in the fossil record, molecular dating uncertainties, and debates over the interpretation of early sponge-like fossils. Still, consensus leans toward sponges originating well before the Cambrian explo
