Tooth?

[Potch Picker]

Hello!  If anyone could help me out with this it would be appreciated.  This opal replacement fossil was mined in New South Wales, about 6 years ago.  I found it in a parcel of Lightning Ridge rough and have been trying to identify it for a while now.  The closest I have come to a positive match (Still not a match but it's close) is the Molar of a giant Marsupial from the order Diprotodontia.  There is a wee problem with this, I've read Lightning Ridge Opal is supposed to be from the Cretaceous and Jurassic periods, a minimum of 66 million years old.  The Diprotodontia existed throughout most of the Pleistocene, about 63 million years off.  HELP!  Thanks in advance everybody. :-)

[Rockwood]

3 minutes ago, Potch Picker said:

 This opal replacement fossil

What indication do you have that it is a fossil ?

[Pterygotus]

It does resemble a mammal tooth but I’m not entirely sure, I don’t see any enamel . Let’s see what others think .

Edited March 10, 2020 by Pterygotus

[Potch Picker]

 

25 minutes ago, Rockwood said:

What indication do you have that it is a fossil ?

Looks like a tooth, 65 + million years old.....opal.   Fig. h....
 

Edited March 10, 2020 by Potch Picker

[Rockwood]

7 minutes ago, Potch Picker said:

Looks like a tooth,

Not to me.

[ParkerPaleo]

I'm not seeing a tooth either.

[Mike from North Queensland]

From memory the opal material is cretaceous / jurassic as noted in your post in age.

It wont be mega fauna as not enough time to opalise.

Looks more like part of a hinge from a clam shell based on photos.

 

Mike

[Rockwood]

18 minutes ago, Mike from North Queensland said:

From memory the opal material is cretaceous / jurassic as noted in your post in age.

It wont be mega fauna as not enough time to opalise.

Looks more like part of a hinge from a clam shell based on photos.

 

Mike

Okay. What indication do you have that it is a fossil ?

[Mark Kmiecik]

Looks too convoluted with too many irregular surfaces to be tooth. It does resemble a broken mollusc hinge more than a tooth.

[Troodon]

+1 for not seeing a tooth

[Potch Picker]

Thanks for the input, don't think it's a clam hinge, I have more than a few of those, the clam also has an open circulatory system, no veins.  I thought it might be part of the internal pulp from a sharks tooth, but I can't find a reference.  (Sharks did apparently make it into the fresh water of Lightning Ridge area) The Marsupial molar is the closest I've come but the time period is off.  Where the veins were is the only part with play of colour, they feed around the "tooth" from the back plate and continue on.  Something with pumping blood, not sure what, but not a clam.  

[Rockwood]

 I don't believe those are veins in the blood vessel way. Rather that they are veins in a crystalline rock.

I see them as an indication that it is not likely a fossil. 

[Tidgy's Dad]

Very pretty. 

But I don't see a fossil either, I'm afraid.

[Potch Picker]

I'm not sure why this, in so many expert opinions, does not fit into the accepted category of fossil.

 

The encyclopaedia Britannica defines fossil as -  a remnant, impression, or trace of an animal or plant of a past geologic age that has been preserved in Earth’s crust.   

 

Perhaps you are unaware of pseudomorphs, or opal replacement fossils. (from opalsdownunder.com.au). They are three-dimensional replicas of ancient organic objects, transposed into potch or precious opal. In those that are pseudomorphs, the silica has filled a simple cavity or void, like jelly in a mould, so that only the basic shape and perhaps the surface texture is preserved. However, many specimens are replacement fossils, in which intricate internal structures (Such as veins) have been preserved by chemical alteration before the cavity was filled by the silica solution. 

Most specimens at the Ridge are a combination of pseudomorph and replacement fossils. Although the transformation to silica has destroyed biomolecular evidence, blood vessels, capillaries and nerve channels may be perfectly preserved. If the potch is transparent, these features are clearly visible below the surface in opalised bones. A surprising aspect is the opalisation of delicate materials like leaves and even dinosaur skin. Many pieces resemble coprolites, reptilian armour scutes or heavy scales; very occasionally, bone specimens seem to show remnants of tendons or cartilage. 

This outstanding quality of preservation is partly because the opal-dirt is extremely fine-grained and an ideal casting medium. Kaolinite, smectite, and illite produce the putty-like properties of the opal clay, the smectite making it plastic and malleable. 

Most opal fossils found at the Ridge consist of potch (colourless opal), therefore any fossils with colour are rare and valuable. Many fossils are damaged by machinery during excavation, as pick and shovel based operations are giving way to machine-driven excavations. Removing fossil specimens can be a delicate operation, and colourless fossil specimens are largely ignored by miners searching for colour.

 

Thanks for your input Gentlemen, duly noted.  

[JohnJ]

29 minutes ago, Potch Picker said:

I'm not sure why this, in so many expert opinions, does not fit into the accepted category of fossil.

 

After looking at dozens of images of lightening ridge rough...probably because it is likely just an oddly shaped piece of opal rough.

[Potch Picker]

Dozens of pics.... ;-D I have over 8000 pieces of rough, yes it is an oddly shaped piece of opal.  

 

Thanks JohnJ, glad an expert was able to weigh in.  

 

Don't be jelly errybody, It's the largest "possibly" tooth in my collection but not even close to the only. Y'all take care. 

[JohnJ]

26 minutes ago, Potch Picker said:

Dozens of pics.... ;-D I have over 8000 pieces of rough, yes it is an oddly shaped piece of opal.  

 

Thanks JohnJ, glad an expert was able to weigh in.  

 

Don't be jelly errybody, It's the largest "possibly" tooth in my collection but not even close to the only. Y'all take care. 

 

Just because people don't agree with you does not make them jealous or deserving of sarcasm.  Please keep that in mind when posting on this Forum.  Thanks. 

[Tidgy's Dad]

It's a nice enough piece but I wouldn't swap it for very much in particular. Certainly not 'jelly'. 

But I would certainly enjoy seeing the rest of your 'possibly' teeth, please, I'm sure they're very beautiful. 

[Rockwood]

3 hours ago, Potch Picker said:

the basic shape and perhaps the surface texture is preserved.

Precisely what would tend to indicate that an object is a fossil. Where it was found only gets it as far as home for consideration.

[Coco]

Hi,

 

You come to the ID for help and you disrespect the people who answer you ? You have no idea how many professional paleontologists are members of this forum, not to mention all those who have more than 30, 40 and even more than 50 years of experience ! So a little respect and humility won’t hurt.

 

I can see the traces of opal in your "fossil", but there’s no form of tooth. If organic matter is replaced by mineral matter in a fossil, the fossil should keep the shape of the tooth since you assume it is a tooth.

Coco

 

 

[MrBones]

Maby a mammal earbone? merely a guess...

[jpc]

In case Potch Picker is still around (but it sounds like he has checked out), I am also voicing mu opinion for not a fossil.  Just potch.  (Also not a mammal ear bone)

[dinosaur man]

Just looks to be a piece of opal rough like @JohnJ said.

[Pemphix]

On 10.3.2020 at 9:49 PM, Mike from North Queensland said:

It wont be mega fauna as not enough time to opalise.

Mike

Mike, you should know that quita a lot of megafauna has been opalized at all:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1833998/

https://peerj.com/articles/6008/

(just some examples)

As we have the first mammals in the cretaceous, they are present in the lightning ridge field fossil-record, too:

http://www.geomaps.com.au/scripts/lightningridge.php

The Tertiary sediments of the field do not bear opal.

In sum: could be fossil, could be cretaceous mammal. But could not be tertiary opalized mammal. 

 

[jpc]

1 hour ago, Pemphix said:

Mike, you should know that quita a lot of megafauna has been opalized at all:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1833998/

https://peerj.com/articles/6008/

(just some examples)

As we have the first mammals in the cretaceous, they are present in the lightning ridge field fossil-record, too:

http://www.geomaps.com.au/scripts/lightningridge.php

The Tertiary sediments of the field do not bear opal.

In sum: could be fossil, could be cretaceous mammal. But could not be tertiary opalized mammal. 

 

I saw this comment and had the same thoughts... I assumed he meant Pleistocene megafauna.

 

I disagree that it could be a Cret mammal.  There is nothing there that says mammal.  Cretaceous or not.