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Cthulhu2

Mammoth/Mastodon VS. Sperm Whale Ivory

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Cthulhu2

Hey guys, since we were on the topic of mammoth/mastodo ivory in the I.D forum, I was wondering if we could quickly talk about Schreger lines. I have found several small ivory fragments with Schreger lines and was looking through articles the other day about them and ID'ing ivory. I saw a picture of a cross section of sperm whale ivory and noticed some lines. I wanted to know are these Schreger as well or are they limited to only those in the Proboscidea order. Below is the picture, a picture of my best ivory chunk, and a link to the website I was looking at. 

 

https://www.fws.gov/lab/ivory_natural.php#whale

 

 

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ynot

Not sure but I think that sperm whale teeth do not exhibit schreger lines.

 

SPERM WHALE AND KILLER WHALE

(Physeter catodon and Orcinus orca)

Sperm whale teeth can be quite large. The average height is approximately twenty centimeters. Killer whale teeth are smaller. Both species display conically shaped teeth with a small amount of enamel at the tips. The rest of the tooth is covered by cementum. Whole cross-sections of killer whale and sperm whale teeth are rounded or oval (figure).

In addition, killer whale teeth show two slight peripheral indentations. The dentine is deposited in a progressive laminar fashion. As a result of this laminar deposition, killer and sperm whale teeth will show prominent concentric dentine rings in cross-section. Killer whale teeth may also display a faint rosette pattern in the dentine cross-section. The dentine is separated from the cementum by a clearly defined transition ring.

Sperm whale ivory Click to see cross section

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Cthulhu2
28 minutes ago, ynot said:

Not sure but I think that sperm whale teeth do not exhibit schreger lines.

 

SPERM WHALE AND KILLER WHALE

(Physeter catodon and Orcinus orca)

Sperm whale teeth can be quite large. The average height is approximately twenty centimeters. Killer whale teeth are smaller. Both species display conically shaped teeth with a small amount of enamel at the tips. The rest of the tooth is covered by cementum. Whole cross-sections of killer whale and sperm whale teeth are rounded or oval (figure).

In addition, killer whale teeth show two slight peripheral indentations. The dentine is deposited in a progressive laminar fashion. As a result of this laminar deposition, killer and sperm whale teeth will show prominent concentric dentine rings in cross-section. Killer whale teeth may also display a faint rosette pattern in the dentine cross-section. The dentine is separated from the cementum by a clearly defined transition ring.

Sperm whale ivory Click to see cross section

So what do you think those lines are in the sperm cross section (Not the rings)? 

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ynot

Artifacts of the picture and not actually part of the ivory. (Possibly reflections on a polished surface.)

They are not continuous across the piece and are all in parallel.

On the bottom right the lines extend into the cementium, schreger lines should not do that.

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Cthulhu2
20 minutes ago, ynot said:

Artifacts of the picture and not actually part of the ivory. (Possibly reflections on a polished surface.)

They are not continuous across the piece and are all in parallel.

On the bottom right the lines extend into the cementium, schreger lines should not do that.

Ah, looks like they need to get a new copy machine, hehe. So Schreger lines are only present in Proboscidea then, huh? 

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ynot

That is My understanding.

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