Small Sloth tooth

[Shellseeker]

Spending my time usefully.  Sorting, collating, identifying, and throwing out or donating finds from last season so that my spouse will allow me to bring another fossil into the house when the season starts again. I tend to over collect and keep many things others would find useless, but there are always some treasures.

One ziploc bag contained a bunch of small goodies, part of which are in this photo:

Some I know, some I do not,  but for this purpose I am interested in the small Sloth tooth:

The tooth is 36 mm length, chewing surface 12.5x16.5 mm. This tooth is small for Sloth, not as small as P. garbani, but small, even for P. harlani, which is the smallest of the Florida ground sloths.  

In this post, @PrehistoricFlorida.identified a similar but different tooth FROM THE SAME LOCATION as a Megalonyx caniniform.

Similar because the two teeth have the exact same texture change going down the side of the tooth.

So, some questions.

1) Is the new tooth a Caniniform?  In photo number 3 of 4, there is wear abrasion on the side of the tooth, but that may not be definitive. I am thinking it is a molariform, but updating my thoughts about side abrasions.

2) What is causing the differentiating texture rings around the top of these 2 teeth? Is this common.

3) We have 2 species of Megalonyx in Florida: M. leptostomus was about half the size of the later M. jeffersonii (Jefferson’s ground sloth). I doubt whether it is possible to differentiate teeth between them.

 

 

It is great to be a fossil enthusiast.  I really enjoy the detective/speculation.   Jack

[ynot]

Sorry that I can not answer any of Your questions, but that is a nice find!

[Plantguy]

Neat specimen Jack. Questions are great ones and out of my league.LOL. Hope Harry or one of the other vert folks can help. 

 

Regards, Chris  

[Harry Pristis]

The shape of the occlusal surface of this sloth tooth is the strongest diagnostic feature because the teeth of large sloths start as small teeth.  That is, there are no deciduous teeth in xenarthrans.

 

Compare with these:

 

 

[Shellseeker]

38 minutes ago, Harry Pristis said:

The shape of the occlusal surface of this sloth tooth is the strongest diagnostic feature because the teeth of large sloths start as small teeth.  That is, there are no deciduous teeth in xenarthrans.

 

Compare with these:

 

God Harry,

I am getting older and my brain is getting slower.

So Sloth teeth grow larger as they age. I am unsure of the process but I think I read something about that from Hulbert once.  I will have to look it up. It says that when I find small sloth teeth, I can not tell if it is a juvenile, female, etc except by size. and I would not be able to differentiate between Megalonyx (J versus L) by their teeth size or occlusal pattern.

In looking at your photos, I believe I have a Nothrotheriops Texanus molar. It is hard to see the occlusal surfaces on the juvenile harlani. Thank you, I am very pleased not only to have found this tooth but to identify on of this species for my first time.

 

I have a couple of more sloth teeth that relate to this discussion. 1st .. a Bone valley tooth missing the occlusal surface but showing the internal structure and layers. Seems to grow in layers like tree rings.

 

After finding the N. texanus tooth, I found an even small tooth (26 mm length x 12.6 mm). Looking at your photos of the Adult harlani tooth, I  think it is a very juvenile harlani caniniform.  What is your smallest sloth tooth?

Thank you, Harry  I have learned some things today about sloths that I will not forget.

 

[Harry Pristis]

Sloth and armadillo teeth grew continuously during life. The term used to describe this condition is "hypselodonty" and is usually applied to mammal teeth. Hypselodont teeth are found in xenarthrans, rabbits, some rodents, and a few ungulates, according to Hulbert.

[Harry Pristis]

11 hours ago, Shellseeker said:

 

 . . .

After finding the N. texanus tooth, I found an even small tooth (26 mm length x 12.6 mm). Looking at your photos of the Adult harlani tooth, I  think it is a very juvenile harlani caniniform.  What is your smallest sloth tooth?

Thank you, Harry  I have learned some things today about sloths that I will not forget.

 

How confident are you that this smallest tooth is not a fragment of an anterior tooth from a giant armadillo?  Consider the possibility.

 

 

[Shellseeker]

3 hours ago, Harry Pristis said:

How confident are you that this smallest tooth is not a fragment of an anterior tooth from a giant armadillo?  Consider the possibility.

 

 

Harry,

Not confident at all. This is my first of these. I saw the horizontal banding, the sharpening wear on the tip, and thought xenatharan and specifically sloth. My previous armadillo teeth are posteriors. In looking on the internet , there are quite a few of these"tips" for sale and almost none like the nice complete one you have.

As I thought sloth, I was thinking of this much larger tooth that I had seen 4 years back. As for this small fossil tooth,  it will be labeled as Holmesina floridanus anterior tooth tip. I am pleased to have another tooth from the Blancan time period.