GordonC Posted April 16, 2019 Share Posted April 16, 2019 Mahantango Formation Sparrowbush NY; Is there enough detail to ID? Looks somewhat like Dalmanites boothi. @piranha Thanks, Gordon Size: it will fit under a dime. 1 Link to comment Share on other sites More sharing options...
Fossildude19 Posted April 16, 2019 Share Posted April 16, 2019 Nice find, Gordon. Looks like a Greenops pygidium. Not sure on the species. Rotated and contrasted. 3 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...
Tidgy's Dad Posted April 16, 2019 Share Posted April 16, 2019 Nice find! Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Al Tahan Posted April 16, 2019 Share Posted April 16, 2019 I think the cephalon is part of what helps distinguish the species but @Fossildude19 is right about the genus. Probably a greenops sp. Link to comment Share on other sites More sharing options...
GordonC Posted April 16, 2019 Author Share Posted April 16, 2019 D. boothi was reassigned to Greenops. See Plate 51 Trilobites of NY. (revised) These from the Hamilton Formation in Maryland GS Plates. Link to comment Share on other sites More sharing options...
DevonianDigger Posted April 16, 2019 Share Posted April 16, 2019 This is almost certainly Greenops boothi. I think it's the only Greenops described from the Mahantango. It is at the very least, the only one in Trilobites of New York described from the formation. Jay A. Wollin Lead Fossil Educator - Penn Dixie Fossil Park and Nature Reserve Hamburg, New York, USA Link to comment Share on other sites More sharing options...
piranha Posted April 16, 2019 Share Posted April 16, 2019 According to Lieberman & Kloc 1997, three Mahantango asteropygine species are reported: Bellacartwrightia phyllocaudata Greenops boothi Greenops grabaui 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 PDF LINK 3 Link to comment Share on other sites More sharing options...
Jeffrey P Posted April 16, 2019 Share Posted April 16, 2019 Given that this fossil was collected on the New York side of the Delaware River would make it probably Mount Marion Formation, Marcellus Shale, Hamilton Group which is equivalent to the Mahantango Formation on the opposite side of the river. I agree that it is a Greenops pygidium. Given the current uncertainty regarding Greenops species differentiations I simply label mine as Greenops sp. This, by the way, is the first specimen of Greenops I've seen east of Madison County. Shoot me if any of you have found one with me and I'm just forgetting. 2 Link to comment Share on other sites More sharing options...
GordonC Posted April 16, 2019 Author Share Posted April 16, 2019 Hi Jeff, I beg to disagree. Pa Geology Survey has mapped the Mahantango to the Delaware river within one mile of the location of collection. NY has done nothing in this area. Political boundaries do not a formation make. Highest regards. G 2 Link to comment Share on other sites More sharing options...
DevonianDigger Posted April 17, 2019 Share Posted April 17, 2019 8 hours ago, piranha said: According to Lieberman & Kloc 1997, three Mahantango asteropygine species are reported: Bellacartwrightia phyllocaudata Greenops boothi Greenops grabaui 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 PDF LINK 4 And then there was Scott, lol! I didn't have a chance to check that particular paper, I figured that Trilobites of NY was going to be enough for this one. My mistake! The pygidial spines do appear to be far too long for G. grabaui, and the proportion of the median pygidial spine seems too narrow for G. boothi. From the few details that are visible in the photos, it looks like the terminal ridge of the axial lobe is rather narrow. That, combined with the pygidial spines, actually leads me to think that B. phyllocaudata might be the best fit. Scott is way better at classification than I am, so I would really love to hear his feedback on this, but these are my two cents. Perhaps even @GerryK could give his thoughts. Jay A. Wollin Lead Fossil Educator - Penn Dixie Fossil Park and Nature Reserve Hamburg, New York, USA Link to comment Share on other sites More sharing options...
hemipristis Posted April 17, 2019 Share Posted April 17, 2019 Paint me impressed that y'all can ID trilobite butts trilobutts? 'Those who cannot remember the past are condemned to repeat it.' George Santayana Link to comment Share on other sites More sharing options...
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