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Help with Pennsylvanian Fish Identification


Hybodus01

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Hi all, seeking some identification help from those familiar with marine vertebrates from the Pennsylvanian black shales (Nebraska, Missouri, etc.)

 

I recently obtained a few ex. Ted White and Bill Rushlau specimens of Romerodus orodontus and a few very nice Iniopteryx rushlaui and one unidentified specimen was included.  Just for context for some reading this, W.D. "Ted" White and Bill Rashlau were very prolific collectors of the Pennsylvanian black shales, primarily the states of Nebraska, Missouri and Iowa.  The specimens that they collected and cataloged are in many museum collections.  The Iniopterygiformes were named as a new order by Zangrel and Case, 1973, with the type species Iniopteryx rushlaui named after Bill Rushlau.  Ted White was a recipient of the The Paleontological Societies Harrell L. Strimple Award, which recognizes outstanding achievement in paleontology by an amateur.   Gerard Case also received this award in 1992.

 

Location:  Hansen Quarry, Papillion, Nebraska.  Stark Shale, Pennsylvanian

T. White collection notes:  Sat., April 5th 1947.  Spec. # 8284.  "Shark - unknown sp.  A 20 x 40 cm. mass of rough textured tissue.  up to 7 mm thick in one area.  No shagreen observed.  General features this is a probable anterior fragment suggesting an individual approx. 1.5 meters in length.  50 or more distinctive teeth unlike any previously found in these shales.  These teeth range in length from 5 to 10 mm.  unlike the fairly common Cladodus tooth, these have a roughly triangular shape and have only 1 crown or cusp.  About 40 of the teeth are partially separated from the mass and are more or less in a normal orientation.  A circular 2.5 cm in diameter defined by some more calcified parts may be an orbit or the symphysial whorl."

 

I do not see any features that point to elasmobranch, but the remains do more resemble some of the "blown out" shark remains I have seen from the Penn. black shales.  The teeth, which are pretty distinctive, do not resemble anything I can turn up.  I also considered that they may be dermal denticles, but the arrangement does not make sense nor can not find any Pennsylvanian aged denticles that match.  The "teeth" indeed measure up to 10mm in length, as described in White's collection notes.   I am hoping some of the forum members familiar with marine vertebrates from the Penn. black shales can help.

 

Pic of full specimen (teeth circled in red), pic of area with teeth, and a close up of some of the more complete teeth. 

Specimen.jpg

Section w teeth (1).jpg

Section w teeth (2).jpg

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    Tim    -  VETERAN SHALE SPLITTER

   MOTM.png.61350469b02f439fd4d5d77c2c69da85.png      PaleoPartner.png.30c01982e09b0cc0b7d9d6a7a21f56c6.png.a600039856933851eeea617ca3f2d15f.png     Postmaster1.jpg.900efa599049929531fa81981f028e24.jpg    VFOTM.png.f1b09c78bf88298b009b0da14ef44cf0.png  VFOTM  --- APRIL - 2015  

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Very interesting specimen and great back story! To me they look more like dermal denticles than teeth. Looking forward to what others have to say.

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Fascinating specimen.

 

It looks like there could be two (or even three) individuals superimposed:

 

Specimen.jpg.b86d86e13f855c790259a642452bdc2f.thumb.jpg.087997f39122a10bc33bb3ab41263bc0.jpg

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Context is critical.

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My gut feeling is this is just one fossil but it's a little dissociated. That happens in these deposits. But I'm not convinced yet that this is a fish. I am actually wondering if the 'scales" or "teeth" might actually be pieces of a cone, and that this might be a really rotted-out plant.

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some close ups without the "denticle/tooth" section.  Pics seem slightly out of focus, but misplaced my glasses this morning!  Ruler, when included in cm.

close3.jpg

close5.jpg

close1.jpg

close6.jpg

close5.jpg

Close2.jpg

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46 minutes ago, westcoast said:

Nothing identifiable there methinks. 

Agree.  The best defining characteristic seems to be the tooth or denticle like structures, but I am at a loss on this one. 

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Certainly doesn’t look like plant material to me. The “denticles” really don’t seem to be associated with the blob either. If they were, you might expect there to be some overlap. My guess is that the two are unrelated, and the blob is just an unidentifiable mass of organic matter.

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