Researchers find fossilized ciliate in 200 million year old leech cocoon

Dec 04, 2012 by Bob Yirka report
Image credit: Hans Kerp et al / Muenster University; PNAS, doi: 10.1073/pnas.1218879109

(Phys.org)—Palaeobiologists from the University of Kansas studying samples taken from the mountains of Antarctica have found a ciliate fossil embedded in the wall of a fossilized leech cocoon which was itself embedded in rock that has been dated back to 200 million years ago. The team outlines their findings in the Proceedings of the National Academy of Sciences.

The ciliate, a member of the Vorticella family, known more commonly as "bell animals" is a single celled protozoan that moves in water through the use of cilia that surround its body and appears to be very similar to many ciliates found today in fresh water ponds. Scientists believe that Antarctica was much warmer during the time when the fossil would have been alive due to the continent being located much farther from the South Pole and thus warm water ponds or streams could have existed where the fossil was discovered.

The specimen was found in taken from Timber Peak in the Eisenhower Mountain Range at an elevation of approximately 10,000 feet. To detect the fossilized ciliate, the researchers had to dissolve the rock using acid in a way that allowed preservation of the () inside. Studying the cocoons under a microscope revealed the presence of the microorganism.

cover themselves completely in a cocoon they create just prior to laying eggs. The eggs – still in the cocoon – are then deposited on nearby surfaces, such as rocks where they are cared for by the parent. In the case of the found fossil, the researchers believe the ciliate became stuck in the wall of the cocoon and then became fossilized as the cocoon itself did so.

The researchers describe the fossil as teardrop shaped with a horseshoe shaped main body. The find is especially intriguing because the ciliate is soft bodied which means it has no skeleton – because of that such finds are extremely rare. It also indicates that researchers have another avenue of research because now ancient leech cocoons may be considered as conservation traps – like amber – and thus other found specimens can be studied more closely to see if other organisms are preserved inside.

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More information: Triassic leech cocoon from Antarctica contains fossil bell animal, PNAS, Published online before print December 3, 2012, doi: 10.1073/pnas.1218879109 . http://www.pnas.org/content/early/2012/11/29/1218879109.abstract

Abstract
Our understanding of the evolution of life on Earth is limited by the imperfection of the fossil record. One reason for this imperfect record is that organisms without hard parts, such as bones, shells, and wood, have a very low potential to enter the fossil record. Occasionally, however, exceptional fossil deposits that preserve soft-bodied organisms provide a rare glimpse of the true biodiversity during past periods of Earth history. We here present an extraordinary find of a fossil ciliate that is encased inside the wall layer of a more than 200 Ma leech cocoon from Antarctica. The microfossil consists of a helically contractile stalk that attaches to a main body with a peristomial feeding apparatus and a large C-shaped macronucleus. It agrees in every aspect with the living bell animals, such as Vorticella. Vorticellids and similar peritrichs are vital constituents of aquatic ecosystems worldwide, but so far have lacked any fossil record. This discovery offers a glimpse of ancient soft-bodied protozoan biotas, and also highlights the potential of clitellate cocoons as microscopic "conservation traps" comparable to amber.

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kevinrtrs
1 / 5 (11) Dec 04, 2012
The research also highlights a major problem for evolution: How could the soft -bodied organism remain unchanged for 200m years? Did no more evolution take place in that species? Just when does evolution supposedly come to a halt in any group?
This is a major headache for the evolutionary paradigm.
aroc91
5 / 5 (6) Dec 04, 2012
The Earth isn't 6000 years old, no matter what you say, kevin. Do your job, mods.
Maggnus
4.7 / 5 (7) Dec 04, 2012
The research also highlights a major problem for evolution: How could the soft -bodied organism remain unchanged for 200m years? Did no more evolution take place in that species? Just when does evolution supposedly come to a halt in any group?
This is a major headache for the evolutionary paradigm.


Your misunderstanding is epic. 1st, evolution does not require change. 2nd how do you know it remained unchanged? And even if it did, so what? Perhaps there was no evolutionary pressure to change. 3rd, what makes you think there is no evolution in the species?

This is not even the most minor of blips, except to the incredibly ignorant.
Parsec
5 / 5 (4) Dec 04, 2012
The research also highlights a major problem for evolution: How could the soft -bodied organism remain unchanged for 200m years? Did no more evolution take place in that species? Just when does evolution supposedly come to a halt in any group?
This is a major headache for the evolutionary paradigm.

Why do you think that? Species do not turn into another species. Do you have in your mind some kind of system where the children always consume or kill the parents?

Normally what happens is new species evolve to occupy unfilled niches in their environment. The old species usually continues until the old environmental niche goes away.
Torbjorn_Larsson_OM
5 / 5 (3) Dec 04, 2012
Creationists shouldn't comment on science. It is hilarious to see.

Here for example, predictions of evolution (200 million year old fossils or evolution wouldn't have time happening - the discovery of deep time was partly inspiring, partly an inspiration for our finding of deep time; similar but not identical species) are claimed to be problems.
VendicarD
5 / 5 (4) Dec 04, 2012
I had no idea that Republicans were 200 million years old.

It does however, explain their intellectual primitiveism.
Mikegyver
1 / 5 (2) Dec 12, 2012
The Earth isn't 6000 years old, no matter what you say, kevin. Do your job, mods.

Science should be an open discussion based on the facts. The fact here and in a lot of cases, is that no evolution has occurred. This fact goes against the general evolutionary theory that species will change over time. 200 million years is a long time for no changes to appear, perhaps the theory falls short here? That is all Kevin is saying.

Please please please keep an open mind and not assume everyone who questions the theory thinks the earth is 6,000 years old. Assuming this invokes the 'straw man' defense and is a weak escape from honest debate.

I believe what Kevin posted is a valid scientific argument and should not be thrown out because to do so would unscientific in itself.

aroc91
5 / 5 (1) Dec 13, 2012
The Earth isn't 6000 years old, no matter what you say, kevin. Do your job, mods.

Science should be an open discussion based on the facts. The fact here and in a lot of cases, is that no evolution has occurred. This fact goes against the general evolutionary theory that species will change over time. 200 million years is a long time for no changes to appear, perhaps the theory falls short here? That is all Kevin is saying.

Please please please keep an open mind and not assume everyone who questions the theory thinks the earth is 6,000 years old. Assuming this invokes the 'straw man' defense and is a weak escape from honest debate.

I believe what Kevin posted is a valid scientific argument and should not be thrown out because to do so would unscientific in itself.



You must be new here. It is not a fact that no evolution has occurred. It is a fact that kevin is a militant young Earth creationist. Don't defend him.