Aspidella

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Aspidella is an Ediacaran disk shaped fossil.

In 1872 Elkanah Billings discovered Aspidella terranovica fossils for the first time in Duckworth Street, St Johns, Newfoundland. They were in a Precambrian outcrop of black shale. Billings was the head paleontologist with the Geological Survey in Canada at the time. Even so his findings were disputed by Charles Doolittle Walcott, an American, who claimed that the shapes in the rocks were concretions formed inorganically. Other explanations were that the circles were gas escape bubbles, or fakes planted by God to lure those with little faith into error. They were the first Ediacaran or Vendian fossils described by a scientist.

For decades Aspidella and its partner fossils were not considered to be Precambrian life forms. This lasted till the work of Reg Sprigg who discovered the Ediacara Hills fossils. Fossils were found in many other parts of the world in rocks of about the same age and became accepted as genuine remains of life forms.

Other places where Aspidella are found is the Bona Vista Peninsula and Mistaken Point in Newfoundland, and the Twitya formation in British Columbia.

The diameter of Apsidella varies from 1 to 180 cm but is usually under 10 cm.

Antiquity of Aspidella ranges from 610 million years ago to 555 mya.

Different morphological forms have been called Ediacaria or Spriggia. In Newfoundland it takes the form of ellipses, from 3 to 8cm long and 1 to 4 cm wide with a central pimple. The pimple is surrounded by sharp ridge edged concentric rings. The disk is a holdfast, with the pimple being where the stalk of the animal was connected. A frond was connected to the stalk, and this frond is what was called Spriggina.

Aspidella has also been used to name fungi of the Amanita genus.