Fish crawl ashore
Fins become limbs — the first four-legged animals
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Tiktaalik, found on Ellesmere Island in 2004, is one of the finest transitional fossils known: a fish with gills and scales, but also with a wrist, weight-bearing ribs and a neck. The move ashore probably had nothing to do with wanting to conquer land, and everything to do with shallow, oxygen-poor wetlands rewarding animals that could gulp air and shuffle between pools. Every tetrapod — humans included — inherited that body plan.
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In shallow, muddy rivers lived fish with strong fins that were almost like arms. They could push themselves through the mud and breathe a little air. Their descendants became frogs, lizards, birds — and eventually us.
Connects to
Part of Terra Saga — the story of Earth on a timeline. terrasaga.org