Half-a-billion-year-old fossil offers new clues to how life exploded on sea floor

University of Oxford ^ | 09/14/18 | Ruth Abrahams

[Simon Green]

Stephen Pates, a researcher from Oxford University’s Department of Zoology, has uncovered secrets from the ancient oceans.

With Dr Rudy Lerosey-Aubril from New England University (Australia), he meticulously re-examined fossil material collected over 25 years ago from the mountains of Utah, USA. The research, published in a new study in Nature Communications, reveals further evidence of the great complexity of the oldest animal ecosystems.

Twenty hours of work with a needle on the specimen while submerged underwater exposed numerous, delicate microscopic hair-like structures known as setae. This revelation of a frontal appendage with fine filtering setae has allowed researchers to confidently identify it as a radiodont – an extinct group of stem arthropods and distant relatives of modern crabs, insects and spiders.

‘Our new study describes Pahvantia hastasta, a long-extinct relative of modern arthropods, which fed on microscopic organisms near the ocean’s surface’ says Stephen Pates. ’We discovered that it used a fine mesh to capture much smaller plankton than any other known swimming animal of comparable size from the Cambrian period. This shows that large free-swimming animals helped to kick-start the diversification of life on the sea floor over half a billion years ago.

[trebb]

Amen!