Tricrepicephalus

Tricrepicephalus
Temporal range: Dresbachian
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Tricrepicephalus texanus, 19 mm
Scientific classification
Kingdom:
Animalia
Phylum:
Arthropoda
Class:
Trilobita
Order:
Ptychopariida
Superfamily:
Crepicephalacea
Family:
Tricrepicephalidae
Genus:
Tricrepicephalus

Kobayashi, 1935
species
  • T. texanus (Shumard, 1861) (type species) = Arionellus texanus, Batyurus texanus, T. coria
  • T. arcuatus Tasch, 1951
  • T. asiaticus Yuan & Yin, 1998
  • T. tripunctatus (Whitfield, 1875) = Arionellus tripunctatus
Synonyms

Paracrepicephalus Lochman, 1936

Tricrepicephalus is an extinct genus of ptychopariid trilobites of the family Tricrepicephalidae with species of average size. Its species lived from 501 to 497 million years ago during the Dresbachian faunal stage of the late Cambrian Period. Fossils of Tricrepicephalus are widespread in Late Cambrian deposits in North America, but is also known from one location in South America. Tricrepicephalus has an inverted egg-shaped exoskeleton, with three characteristic pits in the fold that parallels the margin of the headshield just in front of the central raised area. The articulating middle part of the body has 12 segments and the tailshield carries two long, tubular, curved pygidial spines that are reminiscent of earwig's pincers that rise backwards from the plain of the body at approximately 30°.[1]

  1. ^ Moore, R.C. (1959). Arthropoda I - Arthropoda General Features, Proarthropoda, Euarthropoda General Features, Trilobitomorpha. Treatise on Invertebrate Paleontology. Vol. Part O. Boulder, Colorado/Lawrence, Kansas: Geological Society of America/University of Kansas Press. pp. O249–O250. ISBN 0-8137-3015-5.