Evolutionary Link between Ediacaran and Early Cambrian Multicellular Animals

[Job 33:6]

Paleontologists Find Evolutionary Link between Ediacaran and Early Cambrian Multicellular Animals | Paleontology | Sci-News.com

I think that most of us who follow these things closely are already aware of a number of ediacaran-cambrian transitional species that have been uncovered in the past decade or so, or are currently in the works of being published as we speak.

But, I saw this article describing another species that I hadn't heard of yet, and figured I'd share:

"Professor Wood and co-authors then examined the soft tissues of the Ediacaran animal and compared them with those in animals that evolved later.

They found that Namacalathus hermanastes was an early ancestor of species that appeared during the Cambrian explosion. Among them are types of prehistoric worms and mollusks.

“These are exceptional fossils, which give us a glimpse into the biological affinity of some of the oldest animals,” Professor Wood said.

“They help us trace the roots of the Cambrian explosion and the origin of modern animal groups.”

“Such preservation opens up many new avenues of research into the history of life which was previously not possible.”"

 

[Ophiolite]

• Interesting
• Unsurprising
• A further step towards the time we refer to the Cambrian Expansion, not the Cambrian Explosion.
• Truly tantalising taphonomy triumphant today!

 

[Strathos]

"Professor Wood and co-authors then examined the soft tissues of the Ediacaran animal and compared them with those in animals that evolved later.

There's soft tissue remaining that's that old?

 

[Job 33:6]

There's soft tissue remaining that's that old?

Often times when discussing lagerstatten, they're discussing mineralized soft tissue preservation. So something preserved or protected by minerals.

Lagerstätte - Wikipedia

 

[Strathos]

Often times when discussing lagerstatten, they're discussing mineralized soft tissue preservation. So something preserved or protected by minerals.

So fossils then, not literally the original soft tissue?

 

[Job 33:6]

So fossils then, not literally the original soft tissue?

Well, typically what happens is, you get an animal, it dies. And it has fluids that carry minerals within and throughout and around it. And minerals precipitate from those fluids, typically groundwater for example may precipitate calcite.

So what's left over is hard, not literally soft tissue, but it's in the shape of soft tissue.

Like a petrified tree, or like a dinosaur bone for example.

From the article:
Using an X-ray imaging technique, they found some of the animals’ soft tissues immaculately preserved inside the fossils by a metallic mineral called pyrite.

Pyrite is common in anoxic shallow marine environments, which are ideal for preservation of fossils.

 

[Job 33:6]

Well, typically what happens is, you get an animal, it dies. And it has fluids that carry minerals within and throughout and around it. And minerals precipitate from those fluids, typically groundwater for example may precipitate calcite.

So what's left over is hard, not literally soft tissue, but it's in the shape of soft tissue.

Like a petrified tree, or like a dinosaur bone for example.

From the article:
Using an X-ray imaging technique, they found some of the animals’ soft tissues immaculately preserved inside the fossils by a metallic mineral called pyrite.

Pyrite is common in anoxic shallow marine environments, which are ideal for preservation of fossils.

With respect to these fossils, it's referring to casts and molds of soft tissues. But of course in some cases of mesozoic fossils, minerals have been removed with use of certain acids to reveal some pliable tissues of dinosaur.

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@Strathos the above link would probably help.

Phosphatic fossilization - Wikipedia

But I'm not sure that anyone truly knows how long pliable tissue can truly last when encased by exceptional means of preservation. Like embryos being places in freezer/cryo chambers, some soft things could theoretically last millions of years.

But in this instance, they appear to be speaking of mineral remains and not actual soft tissue.

 

[Job 33:6]

An example of pyritization of soft tissue^ at 1:45.

 

[Ophiolite]

Well, typically what happens is, you get an animal, it dies. And it has fluids that carry minerals within and throughout and around it. And minerals precipitate from those fluids, typically groundwater for example may precipitate calcite.

I realise what you are intending here, but for the non geologist some clarification may be in order.

• When an animal dies typically what happens is that it is scavenged and anything left of its soft tissues decay and its skeleton, whether internal or external, is broken up and eventually destroyed, so that within a year or to, or certainly a couple of decades, nothing whatsover remains of it.
• Very occasionally, and in special circumstances, the more durable skeletal elements may be preserved.
• An in the rarest of all situations traces of the soft tissues may be preserved in the manner you describe in your post.

Thus a vanishingly small number of organisms ever leave a physical trace of their presence and even fewer reveal the character of their soft tissues.