Malcolmt Posted June 22, 2013 Share Posted June 22, 2013 (edited) My friend QuarrymanDave here on the forum asked me to prep what looked to be an unusual trilobite from the veralum formation of Ontario. This is Ordovician . The prep is not finished, I still need to do the fine detail . Even though this is just a cephalon , I think it is an amazing little fossil. It is 31.3 mm at its longest and 22.0 mm at its widest. I have certainly never seen this species in all the times I have been to the location he found it in. It could very well be a rare paraharpes ottawaensis or equally rare dolichoharpes dentoni Please jump in with your identification...... I am currently leaning towards it being dolichoharpes dentoni Edited June 23, 2013 by Malcolmt Link to comment Share on other sites More sharing options...
Auspex Posted June 22, 2013 Share Posted June 22, 2013 Wow; definitely not run-of-the-mill! "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...
jgcox Posted June 22, 2013 Share Posted June 22, 2013 Malcolm maybe Cryptolithus Bellulus? http://drydredgers.org/billwhite/small/088_cryptolithus_bellulus_penn_ord.jpg Link to comment Share on other sites More sharing options...
piranha Posted June 22, 2013 Share Posted June 22, 2013 Paraharpes was synonymized with Hibbertia in Owen & Clarkson 1992. The cephalic brim of Hibbertia is broad and flat with finely pitted ornament. Dolichoharpes looks like the correct ID. Congrats on the great find and prep! Owen, A.W., Clarkson, E.N.K. 1992 Trilobites from Kilbucho and Wallace's Cast and the location of the Northern Belt of the Southern Uplands during the Late Ordovician. Scottish Journal of Geology 28:3-17 Whittington, H.B. 1949 Dolichoharpes and the origin of the harpid fringe. American Journal of Science, ser. 5, 247(4):276-285 Whittington, H.B. 1949 A Monograph of the British Trilobites of the Family Harpidae. Palaeontographical Society, London 447:1-55 1 Link to comment Share on other sites More sharing options...
Bev Posted June 22, 2013 Share Posted June 22, 2013 Super bug and prep! The more I learn, I realize the less I know. BluffCountryFossils.NET Fossil Adventure Blog Go to my Gallery for images of Fossil Jewelry, Sculpture & Crafts Pinned Posts: Beginner's Guide to Fossil Hunting * Geologic Formation Maps Link to comment Share on other sites More sharing options...
PennyT. Posted June 22, 2013 Share Posted June 22, 2013 What a beauty! Nice craftsmanship and the usual excellent scholarship from Piranha. Link to comment Share on other sites More sharing options...
Ludwigia Posted June 22, 2013 Share Posted June 22, 2013 Well done everybody, from beginning to end! Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
TMNH Posted June 23, 2013 Share Posted June 23, 2013 That is certainly an unusual trilobite find! Nice prep too! Link to comment Share on other sites More sharing options...
FossilDAWG Posted June 23, 2013 Share Posted June 23, 2013 Great find, and great prep job! I have never seen a trace of any harpid trilobite in the Verulam, that certainly is a rare find. Don Link to comment Share on other sites More sharing options...
squalicorax Posted June 23, 2013 Share Posted June 23, 2013 Excellent Cephalon My Flickr Page of My Collection: http://www.flickr.com/photos/79424101@N00/sets Link to comment Share on other sites More sharing options...
trilobiteruss Posted June 23, 2013 Share Posted June 23, 2013 Awesome! Link to comment Share on other sites More sharing options...
Caleb Posted June 23, 2013 Share Posted June 23, 2013 That is a beautiful Dolichoharpes cephalon! Caleb Midwestpaleo.com Link to comment Share on other sites More sharing options...
Shamalama Posted June 24, 2013 Share Posted June 24, 2013 Nice find Dave and great job on the prep Malcolm! That is a really cool cephalon you got there. -Dave __________________________________________________ Geologists on the whole are inconsistent drivers. When a roadcut presents itself, they tend to lurch and weave. To them, the roadcut is a portal, a fragment of a regional story, a proscenium arch that leads their imaginations into the earth and through the surrounding terrain. - John McPheeIf I'm going to drive safely, I can't do geology. - John McPheeCheck out my Blog for more fossils I've found: http://viewsofthemahantango.blogspot.com/ Link to comment Share on other sites More sharing options...
Quarryman Dave Posted June 24, 2013 Share Posted June 24, 2013 So happy I found it. At 1st i almost dismissed it as a flexi or ceraurus but the genal spines were so different and striking that I had to give it to malcolm for prepping and ID. What an amazing prep job. thanks Malcolm Quarrycomber Link to comment Share on other sites More sharing options...
piranha Posted June 24, 2013 Share Posted June 24, 2013 Hi Dave, I tracked down some useful research material for you. Dolichoharpes dentoni is evidently a dubious species as the type material has been lost. Presently It appears that Dolichoharpes aff. D. reticulata is the preferred ID for this trilobite. Attached for your files is a PDF of the description and figures from Chatterton & Ludvigsen. Congrats again on your spectacular find! Chatterton, B.D.E. & Ludvigsen, R. 1976.Silicified Middle Ordovician Trilobites from the South Nahanni River Area, District of Mackenzie, Canada.Palaeontographica Abt.A 154:1-106 Dolichoharpes.pdf 2 Link to comment Share on other sites More sharing options...
Malcolmt Posted June 24, 2013 Author Share Posted June 24, 2013 Thanks Scott, this definitely is an excellent PDF for this fossil. Looking at the pictures and the comparing to the fossil in front of me I think we have a 100% match. Link to comment Share on other sites More sharing options...
FossilDAWG Posted June 24, 2013 Share Posted June 24, 2013 Dolichoharpes is shown as occurring in the Verulam in Ludveigsen's volume on the trilobites of Ontario. On the other hand, the genus is not mentioned in B.A. Liberty's extensive faunal list for the Verulam in his GSC memoir on the geology of the Lake Simcoe area, though he does list it for the Bobcaygeon. If Liberty didn't find it, it's safe to say it's really rare in the Verulam. Don 1 Link to comment Share on other sites More sharing options...
cowsharks Posted June 24, 2013 Share Posted June 24, 2013 Couple comments: 1) it's awesome that folks like Pirhana (scott) provide the type of info/materials that they do and 2) is it just coincidence that the pic Scott provided and Malcom's specimen are both missing the main body portion? Is that typical for that type of "rare" trilobite? Link to comment Share on other sites More sharing options...
FossilDAWG Posted June 24, 2013 Share Posted June 24, 2013 Cephalons are always more common than whole specimens. In the case of Dolichoharpes and related trilobites, the sutures that split to let the trilobite molt are at the margins of the head part, so a molted cephalon looks complete in that it is not missing the free cheeks, unlike most other trilobites. The same is true of the Cambrian olenellids (Olenellis, Bristolia, etc), which is why those trilobites are also mainly represented by what appear to be intact heads. The body, on the other hand, is made up of a lot of pieces (thoracic segments, and the pygidium or "tail") that readily break up, so complete specimens require especially rapid burial. Harpids lived partially buried in the sediment on the sea floor, and were good at burrowing, so they may have had to be buried deeper than some other trilobites to smother them after a storm or turbidity flow. That last part is just speculation on my part, though. Don 1 Link to comment Share on other sites More sharing options...
piranha Posted June 24, 2013 Share Posted June 24, 2013 Facial sutures are absent in the olenellids which is regarded as a primitive feature unique among trilobites except where they are secondarily lost (Treatise O 1997). Link to comment Share on other sites More sharing options...
FossilDAWG Posted June 24, 2013 Share Posted June 24, 2013 Thanks Scott, I obviously didn't phrase that clearly with regard to the olenellids. My bad. My point was, with harpids and olenellids molted heads will look intact, unlike Flexicalymene (as one of many examples) where the free cheeks will be dissociated. Don Link to comment Share on other sites More sharing options...
Quarryman Dave Posted June 25, 2013 Share Posted June 25, 2013 Thank you Scott for your information regarding this species the PDF photos exactly matches this specimen Quarrycomber Link to comment Share on other sites More sharing options...
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