USA Cambrian Trilobite fossil lot in Matrix Small No. 019

Cambrian Trilobite fossil in Matrix from the Monte Neva Formation 019: Nice mix of partial and nearly complete trilobites with good detial. Back side has nice cast of sea floor texture. 7.6 oz The Monte Neva Formation is a Middle Cambrian calcareous siltstone exposed in the Little Schell Creek range in White Pine County, Nevada, USA The Cambrian lasted from ~542 million years ago to ~487 million years ago, and was a time of explosive evolution in the marine frontier. This material was deposited on the floor of a vast inland sea present in what is now North America at that time. A number of genus and species of trilobite are present in this shale unit, including Elrathia, Agnostids, and Perenopsis. Nevadia is possible in the lower portion of the unit, and other genera may also appear. Trilobites present may be complete or partial, may be preserved as a mold or intact specimen, and may or may not include the original phosphatic carapace coating. These are all genuine specimens from the E