To put this in perspective, there are very few animals that are not bilateral. Look at the outline on the right side here: http://en.wikipedia.org/wiki/Animal
This new species would be in the odd subkingdoms at the top or a new subkingdom there.
Too bad the preservation killed the possibility of genetic sequencing; phylogenetics seems a lot more useful and accurate to me than morphological taxonomy. But in 1986 I guess genetic sequencing wasn't much of a thing (though the history of phylogentics goes back surprisingly far.)
Formaldehyde and alcohol are still the best way to preserve samples for physical examination when no genetic work is expected. It's a trade-off.
If these had been stored in a genetically-safe way (say frozen, or dried), they may not have been noticed at all, as it tends to collapse structure, especially with gelatinous animals.
Better that they did what they could, certainly. I expect a modern study would take into account DNA, molecular, and even RNA analysis where possible, which were not concerns at the time.
(Modern sample preservation techniques have to consider about half a dozen different types of analysis. Drying, freezing, alcohol, formalin, bleach, are all used for different things. The best all-purpose preservative is high-percentage ethanol, which is okay for DNA for 5-10 years and also preserves structure reasonably well. A NOAA publication on corals suggests you procure some Everclear in an emergency.)
For modern shipboard collections, time is still the enemy ($20K/day to run a ship exhausts a scientific budget quickly, not to mention weather, etc). Surveys have multiple studies going on, so deck operations may be negotiated by scientists down to the minute. Many of the various molecular techniques require careful cleaning of surfaces and tools for each sample, so it's prohibitive to do "general molecular sampling".
For unusual things - in spite of us being scientists, and loving unusual things - the rule is still "Tag it, bag it, look at it later". The "bag it" is usually formalin. If it looks interesting back in the lab, conduct a special study next year to collect some genetics. Of course, we're not expecting to find new phyla very often!
So I'm absolutely sure that 20 years from now, someone could be going through my old bottles, find something truly weird that I missed, and wish that I'd thought to get some $!@#$$(## DNA!
To nitpick: 'phylogenetics' isn't exclusive to using molecular data; the field of phylogenetics was well established long before the advent of sequencing. In modern usage, the term is nearly always referring to molecular phylogenies, but in this context it's a little confusing.
Also, taxonomy is a distinct discipline from phylogenetics, more devoted to classification and naming. The ultimate goal of taxonomists is to assist in communicating about organisms via well-informed classification schemes. To wit, most naming is focused on morphology (e.g. monocots vs. eudicots), but based on molecular phylogenies (hence eudicots (true dicots) vs. the polyphyletic dicots).
It's not uncommon. It's easier to collect than it is to classify. Eg, here's a news report from 1988 about how "[a] 70-foot dinosaur known as Happy stood prominently on display at the Cleveland Museum of Natural History for nearly 25 years before researchers discovered it was a new species." http://articles.latimes.com/1988-09-25/local/me-3747_1_natur...
It points out that "Museum storerooms have become rich hunting grounds for new species because a lack of money and staff has delayed the identification of bones excavated up to 60 years ago" and that "75% of the museum's collection has not been examined closely."
The Natural History museum in the UK has shelves full of samples dating back >100 years that have never been looked at. Furthermore, even ones that have been studied can be revised in the light of new evidence.
So primarily it's a question of man power and triaging samples. Secondly you need a lot of evidence before declaring a new species and various formal steps should be taken (providing a reference sample etc), so that process in itself can take years+.
You are describing domains, and neither the article nor its title suggested the discovery of a new domain. There's no technical reason I'm aware of for "branch" to be restriced to describing domains of life.
This case appears to demonstrate a new phylum, which is two steps below domain, so it's still significant in terms of classification. The fact that the organisms resemble some others we thought died out long ago is also important for evolutionary biology.
What's fascinating is that finding new animal phyla is apparently something that has happened a few times in the last century, and they aren't able to place this creature into a phyla yet - it's close to a jellyfish and comb jellies, but not close enough to be included in the Cnidaria or Ctenophora phylum.
I don't deny the importance of the finding. Bilateria and non-bilateria are huge groups in the animal kingdom and if this animal doesn't fit in one of them is really something.
But (for now, without ADN analysis) it's just a new structure plan. I just find the title about "a new branch of life" a little sensationalist :)
The problem is that it's an exaggeration like: "New article title may be a new branch of linkbait art"
A better title is "Deep sea 'mushroom' may be new branch of animals" or "Deep sea 'mushroom' may be new branch of animal kingdom".
I'm still not 100% happy with the proposed title, but it's more realistic. One of the problems is that it's not a mushroom nor mushroom related. It's only a weird animal with a strange shape that looks like a mushroom.
Wikipedia (bless it's soul) has an update on this - clearly in the kingdom Animalia, http://en.wikipedia.org/wiki/Dendrogramma, they are just trying to figure out which phylum to place it in.
I wondered the same - symmetry seems quite an arbitrary criterion to me, especially because, for example, humans are not really symmetric once you look at the placement of organs. But I could imagine that the mechanism that causes bodies to grow (almost) symmetrically has some deep and unique genetic and biochemical reasons and therefore justifies this classifications.
If archaea are a new branch on the same level as bacteria, why can't new multicellulars be a new branch on the same level as modern multicellular life?
They may be unrelated and different enough - this is one of the ideas about Edicarian fauna.
Archea are less related to bacteria that we thought some years ago. They are as different from bacteria that eukaryotes are different from bacteria. So a new branch of life is justified here since the basic parts of the cell are differents.
The statements saying that this may be a sample of Edicarian fauna are pretty speculative. From the original paper:
> We are aware that the similarities to some of the Ediacaran forms may be independent responses to the same environmental necessities, rather than being evidence of homology.
They found similarities between this and some Ediacaran fossils, but that does not mean that they are related. There are other extant animals with similarities to some Ediacaran specimens with no relation between them.
The speculation can be falsified by analyzing this creatures' DNA and find at which point it diverged from other known life. I hope that is possible!
The speculation can be falsified by analyzing this creatures' DNA and find at which point it diverged from other known life. I hope that is possible!
According to the article, due to the way they were preserved that's sadly not an option with the current samples. They would have to catch new specimen first.
I think guard-of-terra was just expressing a general wish, no necessarily in relation to the mushrooms. Ediacara are so alien and weird - finding a living specimen would be super cool.
I think you're taking that article somewhat out of context. Saying that this "mushroom" is a new branch on the tree of life has a factual, falsifiable meaning.
There is a real thing that we can't really reconstruct in its entirety: the family tree for all life on Earth. Saying it's a new branch means that it diverged so long ago we can't find anything that looks like a common ancestor.
"The researchers did find some similarities to other animal groupings, such as the Cnidaria - the phylum that comprises corals and jellyfish - and the Ctenophora, which includes the marine organisms known as comb jellies. But the new organisms did not fulfil all the criteria required for inclusion in either of those categories."
and
"One way to resolve the question surrounding Dendrogramma's affinities would be to examine its DNA, but new specimens will need to be found. "
made me think this announcement was more about how to place it in our existing taxonomy, and that it reminds to be scene if it really has no common ancestor that we're aware of, as we're still waiting a DNA examination.
> it reminds to be scene if it really has no common ancestor that we're aware of
Evidence for a second tree of life would be incredible. But without further evidence it would be jumping to conclusions to entertain the idea too seriously.
This new species would be in the odd subkingdoms at the top or a new subkingdom there.