Asaphid trilobite

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By Michael Alan Prestwood

Sat 21 Mar 2026

Published 6 months ago.

Updated 2 months ago.

Asaphid trilobite

Lived from 470 to 445 million years ago.

The asaphid trilobite was a broad-bodied, smooth-shelled kind of trilobite common in Ordovician seas. It had a wide oval shape, large head shield, segmented middle, and rounded tail. That would place it roughly around 470 to 445 million years ago, when shallow seas were full of armored arthropods like this one.

Trilobites lived in our ancient oceans for nearly 300 million years, from the Early Cambrian Period about 521 million years ago, to the end of the Permian Period. To the Great Dying that killed off most life about 252 million years ago.

Trilobites do not have any direct living descendant species. They completely vanished during the Permian mass extinction approximately 252 million years ago, making them an evolutionary dead end.

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Michael Alan Prestwood
Author & Natural Philosopher

Prestwood writes on science-first philosophy, with particular attention to the convergence of disciplines. Drawing on his TST Framework, his work emphasizes rational inquiry grounded in empirical observation while engaging questions at the edges of established knowledge. With TouchstoneTruth positioned as a living touchstone, this work aims to contribute reliable, evolving analysis in an emerging AI era where the credibility of information is increasingly contested.