Loads of sponge spicules

[Kcee]

These things are very small and difficult to find but I came across a stone that was littered with hundreds of forams and these spicules. I don't recall seeing anything that look like a sponge so I'm very curious as to why there were so many of these spicules being found in this stone that was found in a desert.

[Fossildude19]

Can't help with your question, but wanted to say how great the pictures came out!

Well done!

[ynot]

The spicules are the "bones" of a sponge and are sometimes silica based (ie.. quartz) that will last longer than the soft body parts.

So after the animal dies the soft parts decay leaving a concentration of the spicules.

Neet finds.

[Doctor Mud]

Like @ynot said, sponge spicules are silica and won’t decay or rot like the rest of the sponge so can survive as fossils long after the rest of the sponge is gone.

Also, being very small they can be transported away from the site where sponges lived and died.

 

It sounds like you are looking at marine sediments since there are forams. As an example I have recently been looking at marine sediments from a core on the shelf off the coast of Australia. There are no sponges living in this environment, but sponge spicules (and forams) are very common. Sponge spicules can also be common in freshwater lake deposits since there are freshwater sponges, but it is usually easy to distinguish between freshwater and marine deposits.

[Doctor Mud]

I realized I have an image of the Australia shelf sediments on my phone. This is what is left after the modern sediments have been treated with alkali to break them up and they have been sieved to remove the clays, there are loads of forams, but also sponge spicules.

 

This is under a scope X40 magnification 

 

 

 

[Kcee]

Why thanks Fossildude19 and ynot...

I find it very difficult to believe but these specimen could be over 2.5 millions years old.

Wow, that's a lot of specimen in that one photo Doctor Mud, how many different types of forams and spicules were in that one sample?

Anyone have any ideal as to what that thing is in the last 2 photos, I can't find anything that looks like it????????

- OMG!!!! ynot….. "Some of them didn't spring far enough"......I have not laughed this hard in a long time...thanks for the wonderful quotes....:)

[Rumi]

Dr. Mud, your photo of the Australian shelf sediments looks most interesting.  There are two clear specimens of Spiroloculina, a miliolid genus that appeared in the Jurassic and continues on in the seas of today.  Murray illustrates two species from Britain, for example.

 

As for the sponge spicules: there seems to be no way to associate them with actual sponge species of the past.  The many different types of spicules have been named, however.

 

Rumi

[Austen]

That photo turned out great, eh? What are you using to get that picture?

[Kcee]

Hi Austen....All of the photos I posted above were taken with a celestron digital microscope. The magnification was 40X to 160X.

[Doctor Mud]

On ‎17‎/‎08‎/‎2019 at 3:02 PM, Kcee said:

Wow, that's a lot of specimen in that one photo Doctor Mud, how many different types of forams and spicules were in that one sample?

It is isn't it!

We haven't looked at the forams yet, I'm not sure someone is lined up to do it yet. The forams are so well preserved and appear (at least to me) to be quite diverse. I normally work on freshwater sediments so I haven't looked at forams since 3rd year during my Geology degree!

 

This sediment was collected to look at the history of harmful algal blooms off the coast of Australia, mainly using fossil dinoflagellate cysts and ancient DNA.

My job is to look at the geochemistry of the mud and to age the core using radiocarbon and lead-210. I took these pictures when I was picking out thigs to radiocarbon date.

 

Like @Rumi said - sponge spicules see, to be not useful for identifying species as the forms are common to many different species.

 

 

[Doctor Mud]

On ‎18‎/‎08‎/‎2019 at 1:13 AM, Rumi said:

Dr. Mud, your photo of the Australian shelf sediments looks most interesting.  There are two clear specimens of Spiroloculina, a miliolid genus that appeared in the Jurassic and continues on in the seas of today.  Murray illustrates two species from Britain, for example.

 

As for the sponge spicules: there seems to be no way to associate them with actual sponge species of the past.  The many different types of spicules have been named, however.

 

Rumi

Thanks @Rumi

The preservation and diversity of forams is wonderful in this sediment. I'm looking at the geochemistry and dating the cores, someone is looking at ancient DNA, and someone diatoms and dinoflagellate cysts. No-one is looking at the forams yet, but it sure would make a nice project for someone.

We "only" collected 3 m of core which dates back about 12,000 years.

[Doctor Mud]

On ‎17‎/‎08‎/‎2019 at 3:02 PM, Kcee said:

Anyone have any ideal as to what that thing is in the last 2 photos, I can't find anything that looks like it????????

I thought maybe an echinoid (sea urchin) spine or part of the echinoid Aristotle Lantern? Is it a tube? I was trying to figure out the 3D shape from the photos.

@JohnJ ?

 

[Kcee]

I can only guess about that strange specimen, I did find a lot of echinoid spines with it so it may very well be something from that family. I have looked at thousands of photos of forams but have not seen anything even close to it. It appears to be solid all the way through. I think I may have a few echinoid spines, I'll see if I can dig them up and post a few.

Wow, Doctor Mud, there has be a ton of forams in the cores you have collected, make sure you don't toss any of those.

[Rumi]

Dr. Mud, I forgot to mention that your sample photo seems to have some ostracode valves in it, too.  Fossil ostracodes are very useful for age determinations.

 

Rumi