pleecan Posted January 14, 2010 Share Posted January 14, 2010 (edited) Calling all fish fossil experts... can someone assist in ID this fish fossil.... fish is 5/8" long Sold as an Unknown Mazon Creek Fish Concretion fossil. Can anyone ID this tiny fish? You can see an eye, some close up shots of fins This is a weird looking fish with a faint pointed snout, pot bellied... with tapering tail, there appears to be a spiked dosal fin very faint, thought it might be a rare Similihariotta dabasinskasi, Zangerl 1979? Comments. Reminds me of a porpoise or dolphin shape. Also include a picture of Similihariotta dabasinskasi for comparison. Thanks in advance. PL Edited January 14, 2010 by pleecan 1 Link to comment Share on other sites More sharing options...
Auspex Posted January 14, 2010 Share Posted January 14, 2010 Sweet fossil, PL! Do you think the "pot belly" might be a yolk sac? "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...
pleecan Posted January 14, 2010 Author Share Posted January 14, 2010 Sweet fossil, PL! Do you think the "pot belly" might be a yolk sac? It could be a yolk sac... as in baby fish.... there has only be one example of Similihariotta dabasinskasi recorded, specimen was photographed returned to owner and where abouts unknown...according to Shibaica book 1997.... this may be the second example of this rare fossil. PL Link to comment Share on other sites More sharing options...
RCFossils Posted January 14, 2010 Share Posted January 14, 2010 Hello Plecan, I took a close look at your fish and am fairly certain it is a paleoniscoid. There is not enough preserved to identify it to the species level however the jaw is clear enough to rule out a chondrichthyan. My best guess would be either Elonichthys peltigeras or possibly wolfii. I do not see any evidence of a yolk sac but if one is preserved, then it would be a tell tail sign that your fish is a Rhapdoderma. This is the only fish known from the Mazon Creek deposit that preserves a yolk sac. I will attach a picture of a specimen with the sac preserved. Link to comment Share on other sites More sharing options...
pleecan Posted January 14, 2010 Author Share Posted January 14, 2010 (edited) Thanks RCFossils for your insights. PL http://www.nhm.uio.no/besokende/faste-utstillinger/fossiler/galleri/montre/a33323.htm http://www.jncc.gov.uk/pdf/gcrdb/GCRsiteaccount2758.pdf http://ca.babelfish.yahoo.com/translate_url?trurl=http%3A%2F%2Fpaleopedia.free.fr%2FActinopterygien_classification.html&lp=fr_en&.intl=ca&fr=slv8-yie8 Edited January 15, 2010 by pleecan Link to comment Share on other sites More sharing options...
RCFossils Posted January 14, 2010 Share Posted January 14, 2010 Anytime Plecan You might be able to clean the piece up a bit more. I would suggest soaking it for a few days in a diluted vinegar. I usually will use about 1/4 cup of vinegar to every cup of water. You can also remove some of the kaolonite (white powdery substance)with a soft tooth brush. Brush very gently until you get a feel for it. You can also leave the concretion out in direct sunlight for several months and it will often times naturally lighten the color of the rock giving the fossil a bit more contrast. Link to comment Share on other sites More sharing options...
pleecan Posted January 14, 2010 Author Share Posted January 14, 2010 I often wondered what that white powdery deposits.... kaolinite... thanks RCF for the cleaning tips. PL Link to comment Share on other sites More sharing options...
glacialerratic Posted January 14, 2010 Share Posted January 14, 2010 (edited) Yes, RCFossils, thanks for the prep tips! Didn't know about the vinegar or the Sun. You've picked up some nice pieces, Pleecan. Tim Edited January 14, 2010 by michigantim Link to comment Share on other sites More sharing options...
pleecan Posted January 14, 2010 Author Share Posted January 14, 2010 (edited) Thanks Tim... PL Edited January 14, 2010 by pleecan Link to comment Share on other sites More sharing options...
Frank Menser Posted January 14, 2010 Share Posted January 14, 2010 Hello Plecan, I took a close look at your fish and am fairly certain it is a paleoniscoid. There is not enough preserved to identify it to the species level however the jaw is clear enough to rule out a chondrichthyan. My best guess would be either Elonichthys peltigeras or possibly wolfii. I do not see any evidence of a yolk sac but if one is preserved, then it would be a tell tail sign that your fish is a Rhapdoderma. This is the only fish known from the Mazon Creek deposit that preserves a yolk sac. I will attach a picture of a specimen with the sac preserved. Looking at this fish I am leaning towards Rhapdoderma. Be true to the reality you create. Link to comment Share on other sites More sharing options...
pleecan Posted January 15, 2010 Author Share Posted January 15, 2010 (edited) Thanks very much Frank for your reply.... here is a link for the Rhapdoderma. http://www.palaeos.com/Vertebrates/Units/140Sarcopterygii/140.234.html http://www.newscientist.com/article/dn12462-how-the-coelacanth-got-its-fins.html http://www.dinofish.com/image4.htm http://www.fossilmall.com/EDCOPE_Enterprises/Mazon-Creek/MC26/MC-fossils-26.htm I am going to try to image the fins to see if there is a match. PL Edited January 15, 2010 by pleecan Link to comment Share on other sites More sharing options...
pleecan Posted January 16, 2010 Author Share Posted January 16, 2010 (edited) I am leaning towards Elonichthys wolfi based on shape of the skull, pectoral lobe fin.. similar dorsal fin... what I thought was a pot belly is the lower jaw portion... there are some bearded projection at the base of the jaws... barb like sensory organs as in catfish or gills or maybe worms feeding on the dead carcass prior to entombment? ..... very distinct dorsal fin... Pectoral Lobe Fin are almost limb like... heavy duty arm like with bony fin projections at the end. PL Edited January 16, 2010 by pleecan Link to comment Share on other sites More sharing options...
paleozoicfish Posted January 20, 2010 Share Posted January 20, 2010 I am leaning towards Elonichthys wolfi based on shape of the skull, pectoral lobe fin.. similar dorsal fin... what I thought was a pot belly is the lower jaw portion... there are some bearded projection at the base of the jaws... barb like sensory organs as in catfish or gills or maybe worms feeding on the dead carcass prior to entombment? ..... very distinct dorsal fin... Pectoral Lobe Fin are almost limb like... heavy duty arm like with bony fin projections at the end. PL Does this fish have two dorsal fins? If it has two dorsal fins, then it cannot be an palaeoniscoid. -PzF Link to comment Share on other sites More sharing options...
Terry Dactyll Posted January 20, 2010 Share Posted January 20, 2010 pleecan...... Very nice purchase!!!, I know they were not that common at all from Crockhey, I think 3 were found in 8 years of collecting.... I scraped one in the last year of the site.... palaeoniscid (I think)...nice to see thanks..... Cheers Steve... And Welcome if your a New Member... Link to comment Share on other sites More sharing options...
pleecan Posted January 20, 2010 Author Share Posted January 20, 2010 Does this fish have two dorsal fins? If it has two dorsal fins, then it cannot be an palaeoniscoid. -PzF Thanks for the diagnostics.... will probably post a few more pics of the upper portions of the fish... I have both halves of the fish and will examine the other half for fin trace at the dorsal region.... PL Link to comment Share on other sites More sharing options...
pleecan Posted January 20, 2010 Author Share Posted January 20, 2010 (edited) pleecan...... Very nice purchase!!!, I know they were not that common at all from Crockhey, I think 3 were found in 8 years of collecting.... I scraped one in the last year of the site.... palaeoniscid (I think)...nice to see thanks..... Thanks Steve.... estimates by (Baird & Anderson)concluded that fish fossils comprise 0.02-0.07% of nodules recovered at Mazon Creek.... fun stuff to collect.... I had hours of fun looking at this particular fossil under the microscope... neat looking surface microstructures.... still probing... Peter Edited January 20, 2010 by pleecan Link to comment Share on other sites More sharing options...
Terry Dactyll Posted January 20, 2010 Share Posted January 20, 2010 Peter..... I dug out a photo of the one I found, I dont know if its of any use for comparison.... Cheers Steve... And Welcome if your a New Member... Link to comment Share on other sites More sharing options...
pleecan Posted January 20, 2010 Author Share Posted January 20, 2010 Thanks very much Steve for the photo! Very nice fossil! ... Your photo makes it a good resource to have.... will have a good look in the comming days. I am currently learning about primitive fishes right now... as I know very little right now on that particular subject... slowly getting educated... lots of fun. Peter Link to comment Share on other sites More sharing options...
pleecan Posted January 24, 2010 Author Share Posted January 24, 2010 (edited) Although there is not muich to work with... can only be seen under the microscope.... I see a single dorsal fin shape ( excludes that of Rhabdoderma)and a unique row of dorsal spiky boney spine projections faint traces (similar to E. wolfii)( appears broken off) distal to the dorsal fin towards the posterior end... there are rows of denticles along the side of the body, scales are ultra fine with ornation.... pectoral fin is round lobe like (excludes E. peltigerus (sharp pointed pectral fins), ........ head is blunt shaped... body stout... still points to Elonichthys wolfii. PL Edited January 24, 2010 by pleecan Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now