일반명 : 삼엽충화석(Trliobite)
학 명 : Hemirhodon amplipyge
지질시대 : 전기캄브리아기로 약 5억4천만년전( Lower Cambrian 540 mya)
지 층 : 마점층(Marjum Formation)
원산지 : 미국 유타( Millard Co., Utah, U.S.A.)
Size: 85 mm

Order: Corynexochida
Suborder: Corynexochina
Family: Dolichometopidae
Species: Hemirhodon amplipyge

This is a very colorful trilobite. It is a large Hemirhodon from Utah. This specimen is complete and has both free cheeks intact and tight. The red coloring on the specimen and matrix is just beautiful. This is a very displayable trilobite from Utah.

The Wheeler and Marjum Formations of western Utah contain from 1400 to 1800 feet of limestone and shale in one of the thickest, best exposed, and most fossiliferous successions of upper Middle Cambrian strata in North America. During the present study, seven stratigraphic sections were measured in the House Range and Drum Mountains, fossils were systematically collected, and the stratigraphic positions of all collections were recorded. From the fossils that were collected, 43 species of trilobites, eight species of brachiopods, four species of molluscs, and two species of porifera are described. Three genera and 21 species of trilobites are new. The new trilobite genera are Trymataspis, Utagnostus, and Utaspis, and the new trilobite species are Baltagnostus eurpyx, Bathyuriscus fimbriatus, Bolaspidella contracta, Bolaspidella drumensis, Brachyaspidion sulcatum, Cotalagnostus laevus, Elrathia alapyge, Elrathia marjumi, Hemirhodon amplipyge, Homagnostus incertus, Lejopyge calva, Linguagnostus perplexus, Modocia brevispina, Modocia laevinucha, Modocia nuchaspina, Peronopsis segmenta, Ptychagnostus akanthodes, Trymataspis depressa, Trymataspis lomaleie, Trymataspis pristina, and Utagnostus trispinulus. Abundant silicified specimens have provided new information concerning the morphology and ontogeny of agnostid trilobites. Trilobites from the Wheeler and Marjum Formations belong to the Bolaspidella Assemblage Zone of the "standard" Cambrian biostratigraphic column for North America. Three local assemblage subzones are defined, which from oldest to youngest are named for the index species Bathyuriscus fimbriatus, Bolaspidella contracta, and Lejopyge calva.