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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This trilobite is a direct-line ancestor to insects, spiders, and crustaceans. It reminds us that early animal life was already complex, varied, and successful.
Subject: Arthropod Evolution.
This trilobite fossil on display in my home is likely an Asaphid trilobite from about 450 million years ago. Trilobites were not our ancestors. Mammals arose from a different branch. Our connection lies deeper in time, through a shared bilaterian ancestor that lived about 600 million years ago, before either lineage took its separate path.
What is the end of the Permian Period 252 million years ago called? .
Answer. The Great Dying.
was first published on TST 6 months ago.
