A Broken Shell in Gale Crater! Curiosity Sol 688.

a reply to: zilebeliveunknown
Being that the OP is taking a stab at this "fossilized shell" based off of Earths fossilized shells. So let's follow his lead and look at actual fossilized shells.

Otherwise this whole thread is void because no one here is a Martian expert.

originally posted by: Swills
a reply to: zilebeliveunknown
I disagree it's a fossilized shell. Looks like a broken rock to me. Google fossilized shells.

Not arguing that it is a shell, but google 'fossil shell imprint' and you will find a lot with almost the exact fossil patterning. It is easy to say that it is not a shell, but it does actually "look like" a fossil shell imprint.

a reply to: Cuervo

Howdy,

See, now that's a good question. How do you know it's a Martian shell if you don't know what Martian shells look like? That's why I asked why it was identified as a shell in the first place...

As for fossilization, it's all basically chemistry and a little physics. The processes that control it would be the same in both places, with Mars perhaps having a slightly different twist.

As it is, you can't even be sure that this is organic. It could be the cleavage of feldspar grains with a little weathering or a covering of Martian sediment. It could be the reverse of a lava flow. It could be ripple marks. It could be the result of differential weathering... It could be any number of inorganic processes. The evidence for organic is very weak, at best.

I'd love to see the shout of joy when/if life is found on Mars. I just don't think it's today. Sorry.
Regards,
Hydeman

a reply to: wildespace

There's nothing shell-like about its shape or appearance.

So what does a shell look like? crab shell looks nothing like razor shell, still shells

a reply to: Halfswede
I have googled it that's why I suggested it. Shells come in all kinds of different shapes and sizes. Please, post the shell that looks like the fossil in question.

originally posted by: Swills
a reply to: Cuervo
I propose the same question to you, how do you what anything Martian looks like?

The entire theme of this thread is based off what we think we know from our experience here on Earth and applying it to Mars.

It is the simple and fast way to grow fos some species.
Mathematic is Universal. You can call it ISOMETRIC GROWT.
This property implies that the projection of any generating spiral on a plane orthogonal to the axis of symmetry produces a curve studied for the first time by Descartes and defined by him as logarithmic or equiangular spiral.

originally posted by: Swills
a reply to: Halfswede
I have googled it that's why I suggested it. Shells come in all kinds of different shapes and sizes. Please, post the shell that looks like the fossil in question.

Shell 1
shell 2
shell 3

Again, not saying it is a shell, but it definitely "looks" like the same patterning you get from fossilized clam shells or partial fossils of other types.

a reply to: Arken

Howdy,

Calcite precipitation (shells are made of calcite here) is not actually an easy thing to do. It requires the input of energy, lots of dissolved CO2, and a high calcium content with lower Mg content in the ocean. It is quite silly for sessile organisms to even have shells if there is no predation... If you find a fossilized predatory Martian snail shell, this might hold more water...

As for isometric growth, I ask that you not call it that. It has a very specific meaning in paleontology. It refers to consistent proportioned growth and is often contrasted with allometric growth. I also do not see a spiral, or even the plane where a spiral could be, so would you mind clarifying?

Now then, I'm just gonna leave this link here and say it's interesting how organic inorganic things can seem...
en.wikipedia.org...

Regards,
Hydeman

a reply to: Swills

how very simplistic piggy @D , how do you know that they are rocks and not extremophiles ?

funBox

a reply to: Halfswede

That's the thing, we can see similarities but that doesn't mean a duck is a duck. Obviously the OP sees the grooves and assumes it a shell. Could it be a shell? Well, truth is we may never know because all we get to look it is a picture. The actual science of how a fossil is created needs to be applied and combined with what we know about Mars. New reports come out all the time and more will follow as we learn about Mars. The simplest question being was there water on Mars? The answer is leaning towards yes. We're there oceans & were they filled with sea life?

Will we find fossilized shells one day on Mars? Maybe, but today is not that day in my opinion.

a reply to: hydeman11
Great post, very informative and actually infuses the science of fossils.

a reply to: funbox

What are we resorting to name calling? It's funny how defensive posters can be in this thread.

a reply to: Swills

I thought that was your pet name , and besides I like pigs , can I borrow your conch ?

funBox

originally posted by: hydeman11
Howdy,

I don't see a shell. I see a rock with what might be ripple marks or possibly the reverse of a pahoehoe like lava flow...

I am curious though, why would you think Mars would have shelled creatures like those on Earth?

Regards,
Hydeman

at one time mars was covered with shallow oceans. though the time necessary for mars to lose it's atmosphere is relatively brief about 350 million years that assumes no oceans and how long were the ocean there? so it is conceivable it had sea life. but doubtful that it had complex life such as bivalves or shellfish. it could be possible but more likely any life was far less complex than a scallop which is what that rock resembles.

What the hell is that sticking out from the rover...
looks like fossilize wood

a reply to: hydeman11

Calcite precipitation (shells are made of calcite here) is not actually an easy thing to do. It requires the input of energy, lots of dissolved CO2, and a high calcium content with lower Mg content in the ocean. It is quite silly for sessile organisms to even have shells if there is no predation... If you find a fossilized predatory Martian snail shell, this might hold more water...

Hmmm... You know that which is now accepted by scientists that MARS housed so much water on the surface and oceans?


And you know that the rusty Mars, after all isn't so rusty?


Kind Regards, Maybe...Maybe Not

a reply to: Halfswede
Excellent examples. Thanks

a reply to: stormbringer1701

350 million years , that's a new figure to me , ill never get the hang of the martian timeline , its almost as bad as earths



funBox

a reply to: stormbringer1701

Howdy,

I completely agree with you. I get that Mars was covered by water at some point, I see the evidence of water in the Martian granites and I said this looked potentially like ripple marks. I get that life could have started on Mars. I also agree that any life on Mars would likely be sessile, like early life on Earth, and not have mineralized hard parts, like early life on Earth. I'd be more inclined to believe this was a trace fossil, a series of worm burrows, than to think it was the external mold of a scallop. (Kudos to you, though, scallop fragment is a good interpretation.)

But it is likely not the external mold fragment of a scallop, as why would Earth like life be present on Mars? That's all I'm asking with that post.

Regards,
Hydeman

a reply to: funbox
Why would you assume pig was my pet name?