This is a 15.7" uncommon plate with 7 Dalmanites Limurus (Green, 1832), 2 Diacalymene sp, 3 Protolaster, 1 Dendrocrinus celcus (Ringueberg, 1888), several specimen of Hallopora elegentula (Hall, 1852), several specimen of Striispirifere niagarensis.
The plate comes was found in the Rodchester shale formation in Middleport, Western New York, USA. It is from the Sheinwoodian age of the Wenlock epoch of the Silurian period, 430 millions years ago.
Supplied with its special metal base.