Asaphiscus facts for kids
Quick facts for kids Asaphiscus |
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Asaphiscus wheeleri, Cambrian shale, Utah | |
Scientific classification | |
Kingdom: | |
Phylum: | |
Class: | |
Order: |
Ptychopariida
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Family: |
Asaphiscidae
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Genus: |
Asaphiscus
Meek, 1873
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Species | |
Synonyms | |
Eteraspis |
Asaphiscus is a genus of trilobite that lived in the Cambrian. Its remains have been found in Australia and North America, especially in Utah.
Distribution
- A. wheeleri occurs in the Middle Cambrian of the United States (Delamaran, Lower Wheeler Shale, Millard County, Utah, 40.0°N, 113.0°W; and Menevian, Wheeler Formation, House Range, Utah, 39.2° N, 113.3° W).
Description
Asaphiscus are average size trilobites of (up to 8 centimetres or 3.1 inches) with a rather flat calcified dorsal exoskeleton of inverted egg-shaped outline, about 1½× longer than wide, with the widest point near the back of the headshield (or cephalon). The cephalon is about 40% of the body length, is semi-circular in shape, has wide rounded genal angles, and a well defined border of about ⅛× the length of the cephalon. The central raised area of the cephalon (or glabella is conical in outline with a wide rounded front and is separated from the border by a preglabellar field of about ⅛× the length of the cephalon, and has 3 sets of furrows that may be clear or inconspicuous. The articulated middle part of the body (or thorax) has 7-11 segments (9 in A. wheeleri), with rounded tips. The tailshield (or pygidium) is about 30% of the body length, is semi-circular in shape, with a wide flat border, and an entire margin.
Reassigned species
Some species originally described as belonging to Asaphiscus have later been reassigned to other genera.
- A. capella = Glyphaspis capella
- A. granulatus = Genevievella granulata
- A. gregarius = Blainia gregarius
- A. minor = Cedaria minor
- A. unispinus = Weeksina unispina
- A Pictorial Guide to Fossils by Gerard Ramon Case