Fish Fossil Plate
Eocene (55.8 to 33.9 million years ago)
Unknown excavation; possible Green River Formation, North America
Dimensions: 20" x 13" x 1"; weight not given

A lake bed fossil slab. Possible Knightia or Gosiutichthys impression and fossil remains; due to both having dorsal fins positioned closer to the head. During the Eocene epoch, the region now comprising Wyoming, Colorado, and Utah was dominated by a vast network of freshwater lakes. The Green River Formation is the geological unit that preserved the sedimentary record of this system, which included Lake Gosiute, Lake Uinta, and Fossil Lake.

Excavations of this type provide important information about ancient earth creatures. Mortality plates suggest these ancient creatures were schooling fish, much like modern herring. This behavior, where fish swim together in groups, makes them vulnerable to a single catastrophic event. This is not a random collection of individual deaths over time. This is a "death assemblage," which captures a single, instantaneous event that killed a large school of fish. Many environmental factors could have created this event: landslide, lake overturn, or an algae bloom.

This is a great example for collectors and those who appreciate natural decorative displays.
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