1. Scientists Find Earliest Signs of Eukaryotic Shell-Making

    Fossilized eukaryotes dating roughly 809 million years ago show evidence of creating mineral shells. Credit: P. Cohen Image credit: None
    Fossilized eukaryotes dating roughly 809 million years ago show evidence of creating mineral shells. Credit: P. Cohen

    On September 27, 2016, paleobiologist Phoebe Cohen of the NASA Astrobiology Institute team at MIT presented a talk entitled “The First Appearance of Controlled Eukaryotic Biomineralization in the Neoproterozoic Fossil Record” at the Geological Society of America (GSA) Annual Meeting in Denver Colorado.

    She spoke about the discovery of fossilized eukaryotes from the Fifteenmile Group of Yukon, Canada that showed evidence of an early form of biomineralization, when an organism produces minerals to build or harden structures like bone or tissue. The observed exoskeletal shells were made out of calcium phosphate, and Cohen’s team dated the fossils back to around 809 million years ago. This is the oldest evidence of biomineralization among eukarya, and the team believes this evolutionary milestone was made possible through predatory pressures and marine conditions that increased the availability of dissolved phosphates pulled from ocean sediment.

    A story detailing Phoebe Cohen’s GSA presentation is available at Science News.

    Source: [Science News]