aplomado Posted March 12, 2015 Share Posted March 12, 2015 I was thinking about buying this small Gerastos trilobite. Does it look ok? 1 Link to comment Share on other sites More sharing options...
Auspex Posted March 12, 2015 Share Posted March 12, 2015 From on-line comparisons, this is a bug that seems not to have obvious eye facets, so my tool kit is exhausted on the first test... "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
LordTrilobite Posted March 12, 2015 Share Posted March 12, 2015 Gerastos have pretty fine facets, so the eyes should look quite smooth. Personally, I think it looks real. It seems to have some nice crisp details on most parts. And the matrix between the segments looks to be on it rather than part of it. With those photo's it's hard to tell though. Olof Moleman AKA Lord Trilobite Link to comment Share on other sites More sharing options...
Fossildude19 Posted March 12, 2015 Share Posted March 12, 2015 The fact that the matrix is broken and has been glued is a good sign. I don't know that Gerastos had any eye facets. Mine certainly doesn't. You could always do a hot needle test, and/or examine with a loupe to see if there are any air bubbles evident on the trilo. Regards, Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 __________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
piranha Posted March 12, 2015 Share Posted March 12, 2015 ...I don't know that Gerastos had any eye facets. Mine certainly doesn't... Every trilobite possessing vision had eye lenses. The densely packed holochroal eye lenses of Gerastos are usually not obvious. 2 Link to comment Share on other sites More sharing options...
Fossildude19 Posted March 12, 2015 Share Posted March 12, 2015 Every trilobite possessing vision had eye lenses. The densely packed holochroal eye lenses of Gerastos are usually not obvious. Thanks for setting me straight, Scott! And now I know. Regards, Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 __________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
sseth Posted March 12, 2015 Share Posted March 12, 2015 It looks legit to me. I have handled thousands of these and think this is the real thing. _____________________________________ Seth www.fossilshack.com www.americanfossil.com www.fishdig.com Link to comment Share on other sites More sharing options...
piranha Posted March 12, 2015 Share Posted March 12, 2015 These figures show Gerastos and the lenses of another typical holochroal eye from an illaenid trilobite. The individual lenses measure ~100 μm! Schoenemann, B. (2007) Trilobite eyes and a new type of neural superposition eye in an ancient system. Palaeontographica Abteilung A, 281:63-91 3 Link to comment Share on other sites More sharing options...
Malcolmt Posted March 12, 2015 Share Posted March 12, 2015 Looks real, very common trilobite from there not really worth faking Link to comment Share on other sites More sharing options...
aplomado Posted March 12, 2015 Author Share Posted March 12, 2015 These figures show Gerastos and the lenses of another typical holochroal eye from an illaenid trilobite. The individual lenses measure ~100 μm! IMG1.jpg Schoenemann, B. (2007) Trilobite eyes and a new type of neural superposition eye in an ancient system. Palaeontographica Abteilung A, 281:63-91 Amazing eyes! Link to comment Share on other sites More sharing options...
Olenoides Posted March 13, 2015 Share Posted March 13, 2015 Yes, it's legit. Those Gerastos are very common, so you can get roughly prepared examples pretty cheap. I've reprepared dozens of them myself. Some can cleanup quite well with an additional 5 -10 minutes of work with air abrasives. I find many/most have some shell restoration, usually to replace flaked shell or they will carve a missing cheek out of rock. I don't see any signs of restoration on that one, just the repaired cracks. 1 Link to comment Share on other sites More sharing options...
Arcadia Posted March 16, 2015 Share Posted March 16, 2015 (edited) If it's fake then it would fool me. Edited March 16, 2015 by Arcadia Link to comment Share on other sites More sharing options...
Fred Posted March 16, 2015 Share Posted March 16, 2015 You can rest assured, this is a genuine Gerastos. Although they are sometimes faked (relatively rarely, because it's not worth it in general, as Malcolmt points out), this one shows sufficient detail which all match Gerastos morphology nicely: the tubercles, 10 segments, general shape and outline of head and tail sections... all ok. Fossildude19 points out the cracks by which the specimen has been found. These are good tell-tales for a genuine specimen. Typically, a crack perpendicular to the body orientation is insufficient to reveal whether the specimen is complete. So the rock is often broken again to see whether the trilobite continues in the matrix. This might explain why this specimen is broken more than once. 2 Paleo database, information and community Link to comment Share on other sites More sharing options...
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