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Helicoprion Mystery Solved!

Jesse

By Jesse
in General Fossil Discussion

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Jesse Regular Member

Jesse

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I am just so happy to finally be able to share this with everyone, it has been killing me keeping it from you guys!

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xonenine Regular Member

xonenine

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Amazing Jesse, congratulations! :)

"Your serpent of Egypt is bred now of your mud by the operation of your sun; so is your crocodile." Lepidus

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Northern Sharks Regular Member

Northern Sharks

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Great job Jesse. Another enigma solved

There's no limit to what you can accomplish when you're supposed to be doing something else

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snolly50 Regular Member

snolly50

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Another win for Science. Outstanding!

Human beings, who are almost unique in having the ability to learn from the experience of others, also are remarkable for their apparent disinclination to do so. - Douglas Adams, Last Chance to See

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Auspex Regular Member

Auspex

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But what if....nah! I think the Fat Lady has finally sung on this one!

What an incredible piece of work!

  • I found this Informative 1

"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!

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markm New Member

markm

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Jesse,

I am very impressed with this! Excellent job, and an answer to many of the mysteries presented by this enigmatic creature!

I can't wait to read the actual article. Very cool!

Mark

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Clayton Jones Regular Member

Clayton Jones

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I'm glad to see the work that has been done to solve the mystery! A decade or so ago the technology used to reconstruct the animal wouldn't have existed. Well done!

WhVUieh.png
My attempt at creating a museum and community center to help people find an interest in the world around them.

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RCFossils Regular Member

RCFossils

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Holy ratfish Jesse!

Seriously, congratulations on helping to solve one of the greatest mysteries in paleontology.

I look forward to reading the paper.

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JohnJ Regular Member

JohnJ

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Amazing work, Jesse. Thanks for sharing it with us.

The human mind has the ability to believe anything is true.  -  JJ

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Roz Regular Member

Roz

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That is the most exciting thing I have read in a long time!

Congratulations to all of you involved!

Welcome to the forum!

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Jesse Regular Member

Jesse

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Thank you guys! I really appreciate the kind words. The 2nd pub is in review and 2 more to write, plus a Ray Troll designed exhibit to build, busy busy.

I may be able to share the published PDF on here as soon as the publisher puts it into circulation, I will check in the morning.

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jpc Regular Member

jpc

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Fantastic. The CT scans are amazing. Way cool.

Are you gonna be in the next installment of Ray Troll and Kirk Johnson driving and fossiling?

Edited by jpc
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trilobiteruss Regular Member

trilobiteruss

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Cool, thanks for sharing Jesse, we have a number of those specimens here in Illinois. It was always an interesting but mysterious specimen. Look forward to the paper!

Russ

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Jesse Regular Member

Jesse

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jpc, he does have some edits to make in his next edition. :D

Until the actual paper can be shared, break down of the elements of the CT scan:

Green-palotoquadrate/upper jaw

Red-specially adapted labial cartilage that buttresses the whorl and likely origin of encasing cartilage

Blue-meckles/lower jaw

Purple-encasing cartilage

Light yellow-teeth

Dark yellow-compound root

Arrow-direction of tooth replacement

bp-basal process

bf-basitrabecular fossa

ep-ethmoid process

lj-labial joint with base of root

pf-lateral palantine fossa

pp-process limiting lower jaw closure (pruitt process, I found and Identified that little bit lol)

qf-lateral quadrate fossa

qmf-quadratomandibular fossa

qp-quadrate process

Hopefully that will help clear up some questions, please feel free to ask for clarification on any and everything!

Edited by Jesse
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AgrilusHunter Regular Member

AgrilusHunter

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Huzzah! Way to go Jesse! I love the reconstructions and I can't wait to read through the manuscript. Congratulations!

"They ... savoured the strange warm glow of being much more ignorant than ordinary people, who were only ignorant of ordinary things."

-- Terry Pratchett

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RichW9090 Regular Member

RichW9090

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Congratulations, Jesse. But I have a question. One of Ray Troll's illustrations that Brian used has a label and an arrow indicating that new teeth originated at the larger, open end of the spiral, which would mean that the teeth, including the roots, got smaller and smaller as they became worn and rolled up - that seems nearly impossible, biologically speaking. I would think that the new teeth originated in the center of the sprial, and "unwound" their way into occlusion.

Rich

Edited by RichW9090

The plural of "anecdote" is not "evidence".

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AgrilusHunter Regular Member

AgrilusHunter

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It's only impossible if you assume the teeth were shed. If the smaller younger teeth were simply 'enfolded' within the whorl as the animal grew, and not lost or shed, then the illustration makes sense. At least that's how I made sense of it.

"They ... savoured the strange warm glow of being much more ignorant than ordinary people, who were only ignorant of ordinary things."

-- Terry Pratchett

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Jesse Regular Member

Jesse

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Huzzah! Way to go Jesse! I love the reconstructions and I can't wait to read through the manuscript. Congratulations!

Ray outdid himself with his reconstructions, he is the true master of the whorl! One of the other authors, Jason Ramsey, helped him "flesh out" the critter. Jason is a shark anatomy expert and did all the muscle reconstructions for an upcoming publication. I was blown away with what they have drawn!

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Jesse Regular Member

Jesse

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Rich, that is a consistent question that comes up at pretty much every talk we have given. It seems intuitive that the teeth would start small in the center, then get progressively larger as they aged until they erupted and were shed. The method in which a shark tooth grows prohibits this method though. When a shark grows a new tooth it starts by building a loosely consolidated enameloid shell, then fills it with dentine, and finally hardens the enamel and caps it with the root. In the case of Helicoprion all of the individual crenulations on the compound root are enamel coated. This would prohibit the teeth from getting larger as the enamel can't be expanded or added to once it is consolidated. To add to the evidence several of the fossils preserve the largest tooth in the spiral in a state of unfilled enamel shells, they are filled with calcite which is a good indicator of a void in the fossil as it preserves. As odd as it is, the spiral of teeth seems to be a novel adaptation for getting the old, used teeth out of the way when they can't be shed. The individual crowns are firmly fixed to the shared root, so well in fact that there are never any loose teeth found, they always come as a set.

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Clayton Jones Regular Member

Clayton Jones

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I wonder what a newly hatched Helicoprion would have looked like... Did they start off with a mini-whirl with just a handfull of teeth that developed before they were born or did they start out with one tooth? How big is the smallest tooth whorl known?

WhVUieh.png
My attempt at creating a museum and community center to help people find an interest in the world around them.

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