crinus Posted November 25, 2014 Share Posted November 25, 2014 This topic is being addressed to GerryK as he is the author of the reference but I am posting it here in case anyone is interested or can chime in. I recently purchased a collection of fossils from the Alpena, Michigan area. I am in the process of incorporating it into my collection and would like to get all the IDs correct. This trilobite was in the collection. It was labeled as Neometacanthus callites, Alpena limestone, Alpena, Michigan. I have no doubt that the locality is correct as the collection contained quite a number of trilobites from the same locality. The previous owner collected these herself and was very precise on locality information. ID is another thing. From your 1997 paper, I infer that the name is not valid and that this specimen may be a Bellacartwrightia jennyae. You do not report this species from anywhere other than New York. Can you confirm that this specimen is B. jennyae. crinus Link to comment Share on other sites More sharing options...
erose Posted November 26, 2014 Share Posted November 26, 2014 Really nice bug! Link to comment Share on other sites More sharing options...
piranha Posted November 26, 2014 Share Posted November 26, 2014 ...From your 1997 paper, I infer that the name is not valid and that this specimen may be a Bellacartwrightia jennyae. You do not report this species from anywhere other than New York. Can you confirm that this specimen is B. jennyae... I agree it matches very well with Bellacartwrightia jennyae. Lieberman and Kloc do mention the species is recorded outside of New York: Only two species of asteropyginines, Bellacartwrightia pleione (Hall, 1861) and B. jennyae, new species, are known with certainty from the strata underlying the Hamilton Group and its equivalents in the Appalachian, Michigan, and Illinois Basins. Lieberman, B.S., & Kloc, G.J. (1997) Evolutionary and biogeographic patterns in the Asteropyginae (Trilobita, Devonian) Delo, 1935. American Museum of Natural History Bulletin, 232:1-127 Link to comment Share on other sites More sharing options...
GerryK Posted December 1, 2014 Share Posted December 1, 2014 Crinus Your trilobite is definitely not a Bellacartwrightia. It appears to be an undescribed species of Greenops. The interesting thing about your trilobite is that it has the usual Greenops features but there are some features in the photo that are not. See list and photo below. Greenops features: 1) The S2 furrow does not reach the glabellar furrow 2) The interior and posterior portions of pygidial pleural segments are of equal elevation 3) The pygidium appears to have the usual 11 pygidial axial rings Non Greenops features: 4) The posterior border furrow appears to be deflected backward on to the genal spine 5) Greenops anterior border is narrow and even in length. Your trilobite appears to have a slight forward protruding lip on the border Features 4 & 5 may be do to crushing or prepping. Different photo angles may clear up what these features are. What make this trilobite different from other described species of Greenops are the long, conical pygidial lappets. There are many Asteropyginae from North America that are in need of revision. I have collected many Asteropyginae that still need to be described from New York, Illinois, Iowa, Pennsylvania and Ontario Canada. It wouldn't surprise me that the Asteropyginae from the Michigan basin are different from the Appalachian basin and the species names from New York would not apply in Michigan.The Michigan basin Asteropyginae are in need of revision. 1 Link to comment Share on other sites More sharing options...
fossilized6s Posted December 1, 2014 Share Posted December 1, 2014 Undescribed ay, that's pretty cool. ~Charlie~ "There are those that look at things the way they are, and ask why.....i dream of things that never were, and ask why not?" ~RFK ->Get your Mosasaur print ->How to spot a fake Trilobite ->How to identify a CONCRETION from a DINOSAUR EGG Link to comment Share on other sites More sharing options...
piranha Posted December 1, 2014 Share Posted December 1, 2014 Gerry, The conical pygidial lappets are very unusual. Since that feature appears to be exclusive to your other Bellacartwrightia spp., is this a transitional Greenops? Link to comment Share on other sites More sharing options...
GerryK Posted December 1, 2014 Share Posted December 1, 2014 Gerry, The conical pygidial lappets are very unusual. Since that feature appears to be exclusive to your other Bellacartwrightia spp., is this a transitional Greenops? Conical pygidial lappets are not exclusive to Bellacartwrightia. I have undescribed Greenops with conical pygidial lappets. Conical pygidial lappets in Greenops may be a pedomorphic feature. Look at the meraspid of Greenops grabaui on Plate 53 in "Trilobites of New York" and see how the lappets are conical but are not in the adult (Plate 54). Also look at Plate 49. 1 Link to comment Share on other sites More sharing options...
piranha Posted December 1, 2014 Share Posted December 1, 2014 Conical pygidial lappets are not exclusive to Bellacartwrightia. I have undescribed Greenops with conical pygidial lappets. Conical pygidial lappets in Greenops may be a pedomorphic feature. Look at the meraspid of Greenops grabaui on Plate 53 in "Trilobites of New York" and see how the lappets are conical but are not in the adult (Plate 54). Also look at Plate 49. A paedomorphic Greenops would be very exciting. Most of us only know about your published specimens. Hopefully you have a follow-up paper planned for the near future! Link to comment Share on other sites More sharing options...
crinus Posted December 2, 2014 Author Share Posted December 2, 2014 Thanks everyone for the input. Really appreciate it. crinus Link to comment Share on other sites More sharing options...
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