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    Missing Link? Darwinius Masillae Transitional Fossil Has Human-Like Nails And Opposable Big Toes
    By News Staff | May 19th 2009 01:00 AM | 5 comments | Print | E-mail | Track Comments
    It's always best not to go overboard but the discovery of Darwinius masillae is pretty darn exciting, because it represents the most complete fossil primate ever found;  the skeleton, soft body outline and even the stomach contents.   It is phylogenetically terrific. Or not.  In any new claim like this, there will be doubts.

    The discovery was made at Grube Messel, near Darmstadt, Germany, where primates are rare and only fragmentary specimens had been located before.    Because it was collected privately and sold in two parts, it is only now that its significance is known.   It's phylogenetically intriguing because of the the absence of a toilet claw and a toothcomb.  Darwinius masillae does have what are described as human-like nails and opposable big toes, which, if this turns out to be a 'stem group' from which anthropoid primates evolved, would place this fossil near the beginning of human evolution.   Darwinius masillae is not simply a lemur fossil but instead part of Adapoidea, a larger group of primates - evidence of the early haplorhine diversification.  In layman terms, this was a lemur-monkey, with features of both groups.

    Darwinius masillae was a female that probably died in her first year of life.

    Darwinius masillae from Messel
    Radiographs of Darwinius masillae.  Relative positions and museum numbers as in Figure 1. Radiographs show that all of plate A is genuine, while cranium, thorax, upper arms (part 1), and lumbus, pelvis, base of tail, and upper legs (part 2) of plate B are genuine.   From  Franzen JL, Gingerich PD, Habersetzer J, Hurum JH, von Koenigswald W, et al. (2009) Complete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology. PLoS ONE 4(5): e5723. doi:10.1371/journal.pone.0005723

    So is this a Rosetta Stone of evolutionary biology?   It will certainly be hyped a lot more than that but it may be warranted.  It's difficult to imagine  studies of Eocene-Oligocene primates that won't reference this discovery.

    Basically it is a lemur monkey that is 'incomplete' but very close - a true transitional fossil.  Biologists hate the term 'missing link' because it isn't very scientific but this is a case where it may be apt.   It's hard to imagine that a female monkey under 2 feet tall discovered 25 years ago could accomplish all that, but after two years of study, the researchers are confident in their results.

    Modern primates began to appear about 55 million years ago, at the beginning of the Eocene epoch, in two superfamilies, Arsioidea and Adapoidea.   Though rare in Messel, the maar lake deposit turned out to be an ideal location because it was a paratropical Eocene rain forest.

    From what can be determined, the fossil was discovered in 1983 and part of it basically hung on a collector's wall for nearly 20 years while another part was purchased by the Wyoming Dinosaur Center in 1991.  In 2007 they were reconciled and work began using X-radiography and microcomputerized tomography.

    Hands and wrist of Darwinius masillae
    Hands and wrist of Darwinius masillae.  Photograph (A) and X-ray image (B) show the specimen preserved on plate A (Fig. 1). (C)— explanatory drawing, where I–V represent digits one to five. (D)— Inset interpretive drawing of the left wrist (box in C).  From: Franzen JL, Gingerich PD, Habersetzer J, Hurum JH, von Koenigswald W, et al. (2009) Complete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology. PLoS ONE 4(5): e5723. doi:10.1371/journal.pone.0005723 

    After so much work, you can imagine they have a great deal of excitement and a connection; they call her Ida.

    Fortunately, discoveries like this have found attention in the right places.   German authorities had plans to turn Messel into a garbage dump.    Now it is instead off-limits to all but Senckenberg Museum scientists, which brings its own level of concern from other researchers.    So enjoy some new possibilities, but until this gets a few years of outside study, take it with a grain of salt.

    Citation: Franzen JL, Gingerich PD, Habersetzer J, Hurum JH, von Koenigswald W, et al. (2009) Complete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology. PLoS ONE 4(5): e5723. doi:10.1371/journal.pone.0005723

    Comments

    logicman
    The PLoS ONE paper has some interesting details.  It is rare for a split fossil to be reunited, especially where private collectors are concerned.  There are so many exciting aspects to this discovery that I am forced to wonder why so many people are writing it up with such gushing hype as 'holy grail, rosetta stone, missing link' etc.

    This discovery doesn't need any hype - but since when did media reporters learn to write hypeless prose?  Thanks and kudos to the scientificblogging news team for getting it right.
    Hank
    Well, if we were doing anything it would be anti-hype.    When a region is limited to employees of one museum, the lineage of a find is suspect and one paleontologist (I won't name) given over toward hype in the past is involved, some caution is warranted.    There will be a rush in the next 6 months to both confirm and debunk parts of this - that's what's great about science.  If it holds up, this is magnificent.

    The hype articles make the front page of Drudge Report, though.   :)   So we'll live without the one million bonus readers hype will attract.
    Well this is a blow: anti-evolutionists will just tell us that instead of a missing link there are now two - one before D. masillae and one after - and that as a result the darwinist case is weaker than ever. It's enough to make you turn creationist. Almost. :)

    The hype though is slightly irritating - surely the point about discovering miising links is that they occupy a place predicted by the evolutionary model (otherwise they're just another evolutionary dead-end), so Ida confirms rather than revolutionises the wider picture, and that's the point to be beating us over the head with.

    Stunning fossil nevertheless, and I'm confident that those involved have taken suitable steps to assure themselves of its authenticity. But why was half "hung on a collector's wall for nearly 20 years"? I've no reason to doubt that all concerned in dealing with the original find acted according to professional norms, but there's something very wrong here. Maybe it's a case for more public money.

    Hank
    It hung on a wall because it was a privately funded dig.    Certainly, more public money (for every dollar in the US budget spent in 2009, $.46 of it is borrowed against future taxes already) can't be a good thing.    More private financing of science expeditions would be fantastic and if the investor wants a souvenir, so be it.  Heck, Neil Shubin named his transitional fossil after his investor, though slyly.

    It's a beautiful fossil.   The history is uncontrolled (anecdotal) but there will be hundreds of scientists trying to debunk it and affirm it.   In science, the truth always wins.   This is certainly no Piltdown Man.
    logicman
    Dave:  the full paper shows that there were many fossils 'up for grabs' over a short period due to forthcoming industrial activity on the site.  The fossil was split because that appears to be a norm for these shale fossils.  I was a bit dubious about the use of resin, but that was explained as necessary to conservation.

    As a child, I was always interested in old fossils, and now I are one.  :-)

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