Elrathina
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Elrathia Temporal range: Middle Cambrian |
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| Elrathia kingii | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Trilobita |
| Order: | Ptychopariida |
| Family: | |
| Genus: |
Elrathia Walcott, 1924 |
| Type species | |
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Conocoryphe kingii Meek, 1870 |
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| Species | |
Elrathia is a genus of ptychopariid trilobite species that lived during the Middle Cambrian of Utah, and possibly British Columbia. E. kingii is one of the most common trilobite fossils in the USA locally found in extremely high concentrations within the Wheeler Formation in the U.S. state of Utah.E. kingii has been considered the most recognizable trilobite. Commercial quarries extract E. kingii in prolific numbers, with just one commercial collector estimating 1.5 million specimens extracted in a 20-year career. 1950 specimens of Elrathia are known from the Greater Phyllopod bed, where they comprise 3.7% of the community.
"...trilobite occupied the exaerobic zone, at the boundary of anoxic and dysoxic bottom waters. E. kingii consistently occur in settings below the oxygen levels required by other contemporaneous epifaunal and infaunal benthic biota and may have derived energy from a food web that existed independently of phototrophic primary productivity. Although other fossil organisms are known to have preferred such environments, E. kingii is the earliest-known inhabitant of them, extending the documented range of the exaerobic ecological strategy into the Cambrian Period."
Even though the generic name Elrathia was first published in the combination E. kingii, a species from the House Range Utah, the name, itself, is derived from Elrath, Cherokee County, Alabama.
E. kingii is a medium-sized trilobite with a smooth sub-ovate carapace that is tapered towards the rear. Thorax is usually 13 segments. Pygidium has four axial rings and a long terminal piece. Posterior margin of the pygidium has a long broad medial notch.
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Wikipedia