30297 - Top Beautiful 2.23 Inch Crotalocephalina (Crotalocephalus) gibbus Lower Devonian Trilobite Marrelomorph arthropods This Eremiasaurus tooth is preserved

This Eremiasaurus tooth is preserved in exceptional way

chromite Fe/Fe+Mg=0

calcium may be partly replaced by thorium

prefrontal contributes moderately to margin of naris and possesses small anterior supraorbital ridge

They lived during the Middle-Late Jurassic Epochs and serve as an biostratigraphic index fossil for that time period

30297 - Top Beautiful 2.23 Inch Crotalocephalina (Crotalocephalus) gibbus Lower Devonian Trilobite Marrelomorph arthropods This Eremiasaurus tooth is preservedNice and well prepared specimen. Crotalocephalina sp, Pibyl and Vanek 1964 (trilobite) Trilobita Phacopida Cheiruridae Parent taxon: Cheiruridae according to P. A. Jell and J. M. Adrain 2002 See also Sepkoski 2002 Sister taxa: Acanthoparyphinae, Anasobella, Ancyginaspis, Arcticeraurinella, Areia, Areiaspis, Borealaspis, Bornholmaspis, Ceraurinium, Ceraurinus, Cerauroides, Cerauromeros, Cerauropeltis, Ceraurus, Chacomurus, Cheirurinae, Cheirurus,