DarasFossils Posted January 1, 2023 Share Posted January 1, 2023 Hello, I am very interested in collecting trilobites and so far I nearly have one from every order (except Agnostia and a questionable Redlichiid), but though I feel I am fairly knowledgable on them overall, I am embarrassed I cannot tell the difference between species such as Phacops, Reedops, Adrisiops, Drotops, Morocops, Austerops, and Chotecops. Species like Hollarops or Morocconites are easy to tell because they have the spines or spikes though their body looks very similar. Usually when I buy trilobites they are labelled but the ones I have gotten as gifts or from rock shops are generally unlabelled. Some are easy to tell due to context (Chotecops are generally preserved in pyrite, Drotops generally being huge,) but Phacops and Reedops?! To me, they look identical, and I've heard the best way to see is counting eye facets, but several of mine have only poorly preserved or partial eyes. I also recently acquired a pair of labelled Adrisiops and I heard that they are referred to as a 'smiley Phacops' but I am not sure where that comes from. I also think the Proetid Gerastos looks quite superficially similar to all of these species, especially when poorly preserved, but I think I can tell that one apart due to it's smaller eyes and different glabella. On top of that, I am very concerned I have some fakes from the time when I was younger and did not know very much about looking for casts or composites and those can have all kinds of crazy things going on that are not in 'real' trilobites. I will try to factor out the suspicious trilobites when comparing my collection. Are there any other context clues or morphology I can look for on these similar species? Comparison photos would be nice to see the visual differences if there are any! Thank you to anyone who helps! Link to comment Share on other sites More sharing options...
Kane Posted January 1, 2023 Share Posted January 1, 2023 Eye lense/file counts are among the most diagnostic features for Moroccan phacopidae. This might present a good start: McKellar R.C., Chatterton, B. D. E. (2009). Early and Middle Devonian Phacopidae (Trilobita) of southern Morocco. Palaeontographica Canadiana 28. PalaeoCan28_1-110.pdf 1 ...How to Philosophize with a Hammer Link to comment Share on other sites More sharing options...
piranha Posted January 1, 2023 Share Posted January 1, 2023 58 minutes ago, DarasFossils said: I also recently acquired a pair of labelled Adrisiops and I heard that they are referred to as a 'smiley Phacops' but I am not sure where that comes from. "Etymology - Combination of ‘adrisio’ (Latin: the action of smiling) + ‘ops’ (Greek: eye), a common suffix of phacopine genera, in reference to the name “smiley Phacops” that has been applied informally to members of the new genus." Van Viersen, A.P., Holland, D., Koppka, J. 2017 The Phacopine Trilobite Genera Morocops Basse, 2006 and Adrisiops gen. nov. from the Devonian of Morocco. Czech Geological Survey, Bulletin of Geosciences, 92(1):13-30 PDF LINK 1 Link to comment Share on other sites More sharing options...
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