Rahul Sharma (Editor)

Elrathia

Updated on
Edit
Like
Comment
Share on FacebookTweet on TwitterShare on LinkedInShare on Reddit
Kingdom
  
Family
  
Rank
  
Genus

Class
  
Trilobita

Phylum
  
Order
  
Elrathia wwwfossilmuseumnetFossilGalleriesUtahTrilobit

Similar
  
Bathyuriscus, Elrathia kingii, Peronopsis, Asaphiscus, Ptychopariida

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.

Contents

Elrathia Elrathia kingii Trilobite

"...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."

Elrathia Elrathia

Etymology

Elrathia Elrathia Wikipedia

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.

Description

Elrathia Gem Elrathia kingii Trilobite Fossil

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.

Elrathia Elrathia marjumi Trilobites

In contrast, E. marjum usually has 12 segments, 5 axial rings, lacks a notched posterior margin and possess incipient antero-lateral spines.

Elrathia Elrathia marjumi Trilobites

The British Columbian species, E. permulta, is much smaller, averaging about only 20 millimeters, and has up to thoracic 14 segments. Because E. permulta lacks several diagnostic features of the genus, it may, in fact, represent a distinct genus.

Synonyms

Elrathia is variously known as Elrathina, which is in fact a separate genus sometimes considered to be a synonym of Ptychoparella, and the species E. kingii is often erroneously called E. kingi (with one i).

References

Elrathia Wikipedia