An new paper addressing mineralization in cephalopods.
The cuttlefish Sepia officinalis (Sepiidae, Cephalopoda) constructs cuttlebone from a liquid-crystal precursor
An new paper addressing mineralization in cephalopods.
The cuttlefish Sepia officinalis (Sepiidae, Cephalopoda) constructs cuttlebone from a liquid-crystal precursor
Last edited by Lagoon Island Pearls; 07-04-2015 at 07:28 PM.
Unfortunately, the page link above isn't working for me. I was able to find it with Google:
http://www.nature.com/srep/2015/1506...srep11513.html
Dave, thanks so much for posting the article. It's outstanding so far. I can see that it will take some time to fully appreciate it.![]()
Last edited by GemGeek; 07-04-2015 at 05:56 PM.
Update: I visited a lease on the Bear Paw Shale in Southern Alberta last summer. This is within what is commonly known as the K-zone. A massive area, where shells have been crushed and/or flattened by subsequent layers of overburden. I discovered three specimens which are important to this discussion. Specimen 1, is an ammonite with considerable shell damage from a predator attack. Clearly, these are mainly blister type pearls, but several present as singular loose pearls. Although the pearls themselves have since been replaced, there is an a convex aragonitic surface with andate margins. I've also attached images of replaced pearls, selected for their immediate proximity to the aragonitic surface of the shell itself.
These were found at the waterline of the river. The ammonite had rolled downhill, smashing to bits yet the debris field remained within a small range. In retrospect, reconstruction proved more ideal than destruction. After all there was no need to smash otherwise intact fossils.
Upon cursory examination, it's apparent ammonites are much larger than the pearl oysters utilized in today's aquaculture. Specimens of 10-20x larger are typical and as such, the size of pearls is directly proportional. Specimen 2 contained several spherical concretions, consistent with Steve's speculation. Likewise, Specimen 3 demonstrates a single concretion.
Alberta has very strict regulations governing fossils. Having unearthed these samples at a shell agreement site, we were duly bound to report and apply to the Royal Tyrell Museum for a disposition. Needless to say, the senior paleontologists would deny the application.
The email read:
Dave
Thank you for your email. Sorry for the delay in getting back to you but I wanted to check a few things before responding. Based on the information provided in your email and what appears to be an overall absence of fossil pearls in our collection, it is unlikely that Disposition would be issued for the fossils in question.
Given your scientific interest in the fossils, the fossils can be deposited here and given Royal Tyrrell Museum (RTMP) accession numbers that can then be used by you and your team when publishing your results. I recommend contacting our Collections Manager, Brandon Strilisky (cc’d on this email) to discuss the details for dropping the fossil off, getting accession numbers and details for moving forward with the scientific study of the fossil. It is our policy to include all relevant collector and/or finder information in our Collections database.
It may also be useful for you or one of your research team members to visit our collections to see if there are pearls associated with any specimens already catalogued here. It is possible that we have pearls in our collection but they haven’t been recognized, yet.
Please let me know if you have any questions.
Dan
Dan Spivak
Head, Resource Management Program
Royal Tyrrell Museum of Palaeontology
T: 403-823-7707 | F: 403-823-7131
Box 7500, Drumheller, Alberta T0J 0Y0 Canada
www.tyrrellmuseum.com
Although they'll retain the lot, I'm the namesake of the discovery by record. Joined by the invitation to collaborate with museum identifying pearls which may already be in the collection. This is a terrific opportunity, especially in light of Covid-19 and it's imposed austerity measures.
For the moment it's prudent to remain skeptical, despite the appearance of one and two adding up. These specimens need closer scrutiny on many levels to be certified.
I've been invited back to the shell agreement next season. There will two challenges. The first, determining a rate of incidence. The second, discovering a true ammolite pearl. That being the discovery of an aragonitic concretion by the reformation of it's own natural structure. At that time, I'm also planning to visit the RTM collection to examine "Blue Zone" fossils. This is very important because this is the zone which produces entire, high quality specimens. I doubt I'll be allowed destructive testing, so it will be incumbent upon me to be highly objective while examining the external integrity of specimens.
Wow. Thanks for the info. Very interesting.
Dave, quite the way to bump the thread! I'll be following.
The Alberta paleontologists might be interested in the precedent of Kieslinger's Triassic Nautilus blister (specimen never traced despite my best contacts at the time).
Steve============
Thank you for the references.
FYI, Specimen 1 and 3 are in my possession. Specimen 1 was acquired though an ammonite shop where I issued a bounty on anything resembling pearls. By a stroke of luck, this piece came to them just a few days later. I was scarcely in Alberta four hours, when the specimen fell into my lap. Three days later, discovered Specimen 2, which was retained by the province. the lot of loose pearls and the host shell fragments were ascended to the collection. Specimen 3 has an even more peculiar story. It was issued a disposition last year and cleared to leave the province. It was given to me at my home in Tofino (for it's dogtooth calcite inclusions) just as we departed for our mining season. I wrapped it carefully and didn't look at it until just the other day, only to realize that it also had a fossil pearl concretion identical to the other specimens.
I also discovered a fossil oyster with a loose oval and a blister pearl. Normally oysters are exempt from disposition applications, but one with pearls was novel to the museum, so it was also ascended.
The same mining partner has 4 sea cans filled with certified ammonite sitting on his property near Red Deer. At this point, I'm sure these occur more often than previously thought. Owing the the issue of concretion and absence of aragonite at the surfaces, no one thought to look. Mistaken for septarian nodules? Technically they are that, I suppose. My first duty with the RTM specimen, would be to reconstruct the ammonite. Once I access the sea cans, I'll be able to start with some IDs and with enough specimens begin destructive testing. Meanwhile, I'm working on some surface microscopy. Looking to find micro-fine aragonite at the surfaces of the concretions.
Below is the oyster with pearls.
Very interesting way to revive this thread Lagoon Island Pearls/Dave!
A great Detective/Paleontology storyline...even Indiana Jones would have his curiosity piqued!
Please keep the info coming as available Dave...and it is great to have you back with us...2021 is already better because of it.
Wow! This is so interesting, and exciting. Congratulations, Thanks, and Welcome![]()
Cathy
CathyKeshi
Hurray! You’ve been missed, and thought of often. Wondering about jade, hoping your next season was smooth going, and all that.
Hi Dave, Thanks so much for posting this information and amazing photos for us! Good to see you back!