Here's an image of something quite astonishing: the fossilized remains of a jellyfish, preserved in fine-grained sedimentary rock in Utah, in the southwest of the United States.  

It is one of a number of exceptionally well-preserved fossil jellyfish which display trailing tentacles, radial muscles, subumbrellar and exumbrellar surfaces, and even possibly gonads -- enough soft-tissue features to definitively categorize them as jellyfish fossils.  

There have been other instances of extensive preservation of numerous jellyfish fossils, such as the amazing discovery of numerous large jellyfish imprints (or "trace fossils") in Wisconsin, but those fossils were found in sedimentary rock created from much coarser sand, and thus they do not preserve the same exquisitely-preserved features of the more-recent Utah find.  Some skeptical paleontologists have even speculated that the Wisconsin jellyfish impressions could have been made by something other than jellyfish (see this article about the Wisconsin jellyfish fossils for some discussion).

These particular jellyfish fossils found in Utah were first described in a peer-reviewed article published in PLOS One in October, 2007, written by scientists Paulyn Cartwright, Susan L. Halgedahl, Jonathan R. Hendricks, Richard D. Jarrard, Antonio C. Marques, Allen G. Collins, and Bruce S. Lieberman and entitled "Exceptionally Preserved Jellyfishes from the Middle Cambrian."  It makes for fascinating reading.

The authors believe, based on widely-held assumptions about the formation mechanisms that created the stratigraphic layers of sedimentary rock on our planet, that these jellyfish are between 501 million and 507 million years old, and date them to about 505 million years ago.

We have already discussed in several past blog posts, such as this one, the possibility that these widely-held assumptions about the strata may be incorrect.  According to hydroplate theory originator and author Dr. Walt Brown, the strata were created over a relatively short period of time, during a world-wide flood event, in which a known process called liquefaction would have sorted the sediments into the layers we see today.  Dr. Brown provides extensive geological evidence from around the globe to support this alternative explanation for the layered strata.  

In fact, the existence of jellyfish fossils such as these Utah fossils and those found in Wisconsin provides powerful supporting evidence for Dr. Brown's theory -- and they are quite difficult to explain under conventional theories.

It should be fairly obvious with a little reflection that creating a jellyfish fossil would require some unusual circumstances.  Jellyfish that die today do not normally turn into fossils -- they are usually eaten by marine scavengers if at sea, and by shorebirds or crabs and other shore scavengers if washed up on shore.  

Those trying to explain the formation of jellyfish fossils from long ago often propose that the fact that they were not eaten by scavengers shows that these jellyfish must have evolved before any scavengers existed.  However, even if a jellyfish dies and is not devoured by relatively large scavengers, microbial decay would generally be expected to reduce them to particles long before the sand could turn into sandstone around their carcass.  In order for fossils of any sort to be preserved, they usually must be smothered somehow in thick wet mud that seals out bacteria, and even then the soft tissues are generally not preserved but only the bones. 

For more discussion on the origin of fossils, and on the few scenarios in which some soft tissues of animals such as dinosaurs have in fact been preserved, see this previous post entitled "The origin of fossils" and this previous post entitled "Soft tissue in T.Rex fossils."

The problem with such scenarios for the preservation of jellyfish, however, is the fact that jellyfish are very soft and delicate, and even if buried rapidly under tons of wet sediments (to preserve them from bacteria) they might not be expected to leave much of a trace.  Even the famous Burgess Shale, which contains fossils of worms and of soft tissues from segmented arthropods and molluscs, does not seem to preserve many jellies, if any.

Thus, for jellyfish to be preserved at all, those who hold to the conventional non-catastrophic theories of geology must posit extremely unusual circumstances including "anoxic conditions" (proposed in the article discussing the Utah jellyfish) and mass strandings of jellyfish on shallow shorelines, followed by rapid burial (proposed by paleontologists discussing the Wisconsin jellyfish fossils and quoted in this article). 

Incredibly, the Wisconsin sandstone containing the numerous jellyfish fossils (some of which are two and even three feet in diameter) has multiple layers of sandstone containing other jellyfish fossils -- at least six different layers!  According to the conventional theory, then, these amazingly unique conditions for preserving jellies took place numerous times in the exact same spot, so many thousands or millions of years apart that the fossils were preserved in successive layers in the sedimentary stack!  

"It's a spectacular find," says one paleontologist quoted in the article linked above, and that article's author continues: "More so, he adds, because the hapless jellies are found in several different layers of fossilized beach. 'It's not just a one-off event, it happened at least six times.'"

The exact mechanism by which these ideal conditions preserved the jellyfish are not precisely described, either.  We are left with a kind of vague "hand-wave" and the assurance that the right conditions would preserve a jellyfish for millions of years in stone.  This type of vague but confident description is not unusual or uncommon when describing hard-to-explain marine fossils (I remarked on it in the post entitled "Crinoids on Mount Everest?" here as well).

While it is possible that such ideal conditions somehow cropped up once, it is difficult to believe that they did so over and over again.  In light of this improbability, it would certainly seem to be advisable to seek a better explanation, and Dr. Brown supplies one in his book, which is available to study online in its entirety for free at this location (hardbound versions can be ordered from the same site).  

In this page of his book discussing the principles of liquefaction, and the way that liquefaction would have created sedimentary layers during a catastrophic global flood, Dr. Brown explains how the formation of these layers of jellyfish fossils could have been created:
Multiple liquefaction lenses, vertically aligned during the last liquefaction cycle, trapped delicate animals such as jellyfish and preserved them, as the roof of each water lens gently settled onto its floor.  [See section 8 on the page indicated].
Dr. Brown gives more detail about these "water lenses" and how they are supported by geological evidence and are consistent with the principles of liquefaction and physics on this page of his book.  A previous post discussed this aspect of Dr. Brown's theory in light of the fossil record at the so-called "Dinosaur Dance-Floors" which have been found in sites in both North and South America.

Dr. Brown's theory would also help to explain another aspect of the mysterious jellyfish fossils which is not mentioned as a "problem" in any of the conventional articles about jellyfish, and that is the fact that these jellyfish -- supposed to have perished over 500 million years ago -- are almost identical to modern jellyfish.  In fact, the authors of the paper about the jellyfish in Utah note that the features of the fossil jellyfish pictured above suggest that it may be a narcomedusa.  A modern narcomedusa is pictured below.

They do not go so far as to definitively categorize the fossils as belonging to a specific taxon of jellyfish, saying:
Still, even with the level of detail preserved, we hesitate to definitively assign any of these fossils to a specific taxon because taphonomic factors can conspire to make particular features of specimens difficult to interpret and even modern jellyfish possess few diagnostic features. We do, however, discuss distinctive features exhibited by these specimens that indicate they share affinities with certain modern cnidarian clades.
They do point out strong similarities to modern narcomedusae and to modern box jellies.  

The lack of transformation of these jellyfish over a period of many hundreds of millions of years would seem to be somewhat problematic for conventional theories, and particularly for supporters of Darwinian evolution.  However, if the fossils were created all at once during a catastrophic flood event, then it is no longer necessary to maintain that they were created five hundred million years ago and that jellyfish have stubbornly refused to change over the intervening millenia (even as dinosaurs supposedly evolved out of some predecessor species and then evolved into birds or something else in the interim).  

Thus Dr. Brown's theory solves that difficulty of explaining these jellyfish fossils, just as it solves the problem of having to posit incredibly rare (and vaguely understood) conditions arising over and over to preserve jellyfish in successive layers of sediments over long periods of time in the same location in Wisconsin (and then again in Utah). 

Of course, any theory which undermines Darwinism will be vigorously resisted by conventional academia.  Thus we can expect that the sensible and precisely-described mechanism Dr. Brown offers for the creation of jellyfish fossils will be ignored by most paleontologists, who will instead offer speculative, vaguely-described, and highly-improbable scenarios (with great confidence and certainty).  This is regrettable, because the presence of these jellyfish fossils seems to invite reconsideration of the conventional theories, and should certainly undermine the easy confidence with which ancient fossil-forming mechanisms are often described.

It is important that the general public be made aware of the amazing discovery of thousands of jellyfish fossils in recent years.  These fossils would appear to be yet another strong piece of evidence which supports the hydroplate theory of Dr. Walt Brown.