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IONIATE POWER RUBRIC
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Tonian World: Reflects my fascination with historical geology. The Tonian period is the first geologic period of the last billion years, stretching from 1,000 million to 850 million years ago. The six short movements are a fanciful endeavor to capture certain aspects of this far, long-ago time
1. Neoproterozoic: The Neoproterozoic Era is the unit of geologic time from 1,000 to 541 million years ago. We are concerned here with the first of three periods, the Tonian
2. Acritarch: Acritarchs are organic microfossils, present from approximately 3.2 billion years ago to the present. During the Tonian Period, acritarchs started to increase in abundance, diversity, size, complexity of shape, and especially the size and number of spines.
3. Ramathallus lobatus: Red algae first appeared some 1.5 billion years ago. The Tonian saw an increase in multicellular complexity as represented by Ramathallus lobatus. These fossil bear a resemblance to some types of modern red algae.
4. Metazoa: The term for multicellular animals. Many think it was the later, Precambrian Ediacarian fauna that saw the first appearance of complex animals, but that is not so. It was during the Tonian that they first appeared.
5. Otavia antiqua: Is the most well known example of a multicellular animal from the Tonian. This animal has been described as an early sponge.
6. Sturtian glaciation: This is the first of several worldwide glacial events that occurred during the time called “Snowball Earth,” and marks the end of the Tonian Period.