Rivergods smiled

[Shellseeker]

Sometimes it is hard to believe how lucky I am in hunting fossils. I was on the Peace River prospecting. Mostly small teeth (no GWs, Makos, Megs).  My find of the day was half a giant tortoise humerus.

With the afternoon moving to a close,  this Tusk dropped into my sieve.  I think that this is a Mammoth yearling and I am looking for confirmation or skepticism. 

1) It is about 7 inches long with the tip broken. It is 2.25 inches (57 mm) in diameter at the butt.

2) The butt end I believe to be round rather than oval and not broken. I have seen many broken tusks and they do not have concentric circles in a flat pattern.

3) The segment is straight , not curved. There is a Youtube video on Woolly Mammoth tusk growth.  It seems to curve after the 1st year. In the photo, my find might be the green section.

4) I will figure out Mastodon versus Mammoth once I allow the tusk to dry and see the schreger lines.

Hopefully, TFF will be able to ID first..  @digit has been playing with hosenose tusks and @Harry Pristis has lots of skills in all fossils Florida.  Please chime in...

 

I will check responses with my cell.  This is one of those rare occasions where I am going hunting on back to back days.. I must be feeling my oats.

 

[musicnfossils]

Amazing find. That first sentence perfectly describes my luck lately as well...from a partial dinosaur tail, partial dinosaur foot, teeth, etc. Please post pics of your other recent finds too! 

[jcbshark]

Great find Jack!!!

[digit]

Looks "tucky" to me too. Any other proboscidean (hose-nose) finds in the same area? I know that when John @Sacha was finding mammoth teeth in a gravel-filled pit in the limestone bottom at the "Elephant Graveyard" site we were digging some many years back that he was also finding broken pieces of mammoth skull. Proboscidean skull is not solid as that would make the it unnecessarily heavy. It is instead filled with air spaces (sinuses) separated by thin flat structural walls in various orientations which provide structural rigidity without being overly dense. Curious to know if this tusk was an isolated find or if you were in "the zone" with additional material turning up?

 

 

Somehow, I cannot look at the image above of a modern elephant skull where someone had carefully removed the outer surface of the skull to reveal the sinus cavities without hearing "Ack ack!".

 

 

Your tusk is likely too peeled away on the surface to show any signs of enamel. Gomphotheres (a familiar proboscidean to those who volunteer at Montbrook) have interesting tusks which are quite straight with only a slight curve and a strip of enamel running down their length.

 

Cheers.

 

-Ken

 

 

[darrow]

Nice find! 

From your photo showing the cross section I'd say this specimen is not Mammoth based on Schreger angle I can see being greater than 90°.  

[digit]

3 hours ago, digit said:

Looks "tucky" to me too.

Uh, make that "tusky".

 

 

Cheers.

 

-Ken

[Shellseeker]

On 5/4/2021 at 9:11 AM, darrow said:

Nice find! 

From your photo showing the cross section I'd say this specimen is not Mammoth based on Schreger angle I can see being greater than 90°.  

Better photos.  Darrow, Can you mark the lines on one of these photos.. My eyes are having trouble distinguishing.

 

@digit

 

I have saved the peeled Skull image,  a great learning device.  Thanks

 

There is lots of material that is Elephant sized... Process from Vert, some larger vert pieces,  and lots of small broken up Mammoth teeth. 

On the Gomph, I also have another tusk,  that I thought was Gomph,  with no similar band..  Do all Gomphs have the enamel band?

 

[minnbuckeye]

Jack, Great find!!! Seems like you have been on a roll lately, or is it just time put into the hunts?? Keep up the good work.

 

 Mike

[Grimlock]

Sweet find Jack!!!

[darrow]

On 5/5/2021 at 9:44 PM, Shellseeker said:

Better photos.  Darrow, Can you mark the lines on one of these photos.. My eyes are having trouble distinguishing. 

 

Jack, the river has polished away much of the detail making it difficult to distinguish the lines particularly if you try to focus in on the detail in a small area.  I find they are more easily perceived try to visually scan the entire cross section without magnification or even better display a high resolution picture of the cross section on a large display and increase the size until the cross section fills the screen.  Then perhaps counterintuitively, step back away from the display perhaps six feet or so and the lines may be perceived as broad arcs across the surface.  If you resist focusing on the small detail, your brain will tend to fill in the discontinuities in the lines.  The lines might also be perceived by viewing the cross section as you rotate or gradually shift the orientation with respect to oblique lighting.  I marked some of the lines I perceive in the picture you provided below...

 

Edited May 7, 2021 by darrow
orient picture

[Shellseeker]

47 minutes ago, darrow said:

Jack, the river has polished away much of the detail making it difficult to distinguish the lines particularly if you try to focus in on the detail in a small area.  I find they are more easily perceived try to visually scan the entire cross section without magnification or even better display a high resolution picture of the cross section on a large display and increase the size until the cross section fills the screen.  Then perhaps counterintuitively, step back away from the display perhaps six feet or so and the lines may be perceived as broad arcs across the surface.  If you resist focusing on the small detail, your brain will tend to fill in the discontinuities in the lines.  The lines might also be perceived by viewing the cross section as you rotate or gradually shift the orientation with respect to oblique lighting.  I marked some of the lines I perceive in the picture you provided below...

 

 

Thanks, Darrow, I am grabbing more photos,  and will try your suggestions

 

There are the clear directional lines and then the verticle lines to the clear that seem to show a 125 degree angle.  but I am not sure...  How do you read it?

[darrow]

I agree around 125 or 135.

[digit]

On 5/5/2021 at 10:44 PM, Shellseeker said:

Do all Gomphs have the enamel band?

I know the species we have at Montbrook certainly does (the photos are of specimens from there). There are actually several species of gomphs that can be found in Florida and I'll have to pass this question on to Richard who I'll be seeing for 6 hours of digging on our last day of the season at Montbrook tomorrow. Will pass on anything I learn. I believe all gomphs may have 4 tusks (2 upper/2 lower) but I'll have to confirm that "fact" as well tomorrow.

 

 

Cheers.

 

-Ken

[Shellseeker]

On 5/6/2021 at 7:42 AM, minnbuckeye said:

Jack, Great find!!! Seems like you have been on a roll lately, or is it just time put into the hunts?? Keep up the good work.

 

 Mike

Mike,

Sorry for Delay in responding.  Been busy hunting now the the river has dropped drastically.   After long periods of heavy rains,  the River has been churned up.  Over the years, many of my better finds have been during that period.

[Shellseeker]

2 hours ago, darrow said:

I agree around 125 or 135.

Ken will likely have to educate us about Gomph, but I have been used to saying either Mammoth or Mastodont... so I think it is Mastodont as the default. It is just that I have a Gomph tusk from Florida and the butt end looks like this.

 

Thanks for your help, Darrow  Confirmation is always appreciated

 

[digit]

59 minutes ago, Shellseeker said:

It is just that I have a Gomph tusk from Florida and the butt end looks like this.

The earlier species had 4 tusks with the later ones being more vesigial. As a complete guess (unencumbered by the thought process) the smaller oval tusk above may be either a juvenile or a more vestigial lower. Definitely out of my depth with theories of the hose-nosed creatures that once roamed our state but I've got access to Richard which is a great conduit to answers.

 

 

Cheers.

 

-Ken

[darrow]

Schreger angle vary considerably with radial and longitudinal location within a tusk so we end up with a range of angles for a particular species.  We can distinguish BETWEEN some species like Mammoth and Mastodon where the range of angles do not overlap however in the case of Mastodon and Gomphothere where there is considerable overlap in the range of angles you’ll need another diagnostic feature to distinguish between them.  Absent that you have to fall back on probabilities like the occurrence rate of the two species in the location where the tusk was collected.

 

To illustrate the range of angles in a species and the overlap between species...

Edited May 9, 2021 by darrow

[fifbrindacier]

On 5/4/2021 at 2:19 PM, digit said:

 

On 5/4/2021 at 2:19 PM, digit said:

Somehow, I cannot look at the image above of a modern elephant skull where someone had carefully removed the outer surface of the skull to reveal the sinus cavities without hearing "Ack ack!".

Nice comparison !

[digit]

1 hour ago, fifbrindacier said:

Nice comparison !

Couldn't resist.

 

 

Cheers.

 

-Ken

[Shellseeker]

2 hours ago, darrow said:

You’ll need another diagnostic feature to distinguish between them.  Absent that you have to fall back on probabilities like the occurrence rate of the two species in the location where the tusk was collected.

Agree on the difficulty to differentiate Gomph from Mastodont.  My tendency is based on my find rate and the find rate of friends for Gomph teeth found in the Peace River over the last 10 plus years.  Only a data point but it would imply  65 Mammoth teeth finds , 33 Mastodont teeth finds and 2 Gomph teeth finds in the Peace River.  Teeth fragments would have to be 3 inches minimum.

I personally have found 8 complete Mastodont teeth,  no  complete Gomph teeth in the Peace River.