Tuesday, January 7, 2020

How Was Archaeopteryx Discovered

Fittingly for a creature that most people consider to be the first bird, the story of Archaeopteryx begins with a single, fossilized feather. This artifact was discovered in 1861 by the paleontologist Christian Erick Hermann von Meyer in Solnhofen (a town in the south German region of Bavaria). For centuries, Germans have been quarrying Solnhofens extensive limestone deposits, which were laid down about 150 million years ago during the late Jurassic period. Ironically, though, this first, wispy hint of the existence of Archaeopteryx has since been downgraded by paleontologists. Von Meyers discovery was quickly followed by the unearthing of various, more-complete Archaeopteryx fossils, and it was only in retrospect that his feather was assigned to the Archaeoteryx genus (which was designated in 1863 by the worlds most renowned naturalist at the time, Richard Owen). It turns out that this feather may not have come from Archaeopteryx at all but from a closely related genus of dino-bird! Confused yet? Well, it gets much worse: it turns out that a specimen of Archaeopteryx had actually been discovered as early as 1855, but it was so fragmentary and incomplete that, in 1877, no less an authority than von Meyer classified it as belonging to Pterodactylus (one of the first pterosaurs, or flying reptiles, ever to be identified). This mistake was rectified in 1970 by the American paleontologist John Ostrom, who is famous for his theory that birds evolved from feathered dinosaurs like Deinonychus. The Golden Age of Archaeopteryx: London and Berlin Specimens To backtrack a bit: Shortly after von Meyer discovered his feather, in 1861, a near-complete Archaeopteryx specimen was unearthed in another part of the Solnhofen formation. We dont know who the lucky fossil-hunter was, but we do know that he gave his find to a local doctor in lieu of payment and that this doctor then sold the specimen to the Natural History Museum in London for 700 pounds (a massive amount of money in the mid-19th century). The second (or third, depending on how youre counting) Archaeopteryx specimen suffered a similar fate. This was discovered in the mid-1870s by a German farmer named Jakob Niemeyer, who quickly sold it to an innkeeper so he could buy a cow. (One imagines that Niemeyers descendants, if any are alive today, deeply regret this decision). This fossil traded hands a few more times and was eventually bought by a German museum for 20,000 goldmarks, an order of magnitude more than the London specimen had fetched a couple of decades before. What did contemporaries think about Archaeopteryx? Well, heres a quote from the father of evolutionary theory, Charles Darwin, who had published the Origin of Species only a few months before Archaopteryxs discovery: We know, on the authority of Professor Owen, that a bird certainly lived during the deposition of the upper greensand [i.e., the sediments dating from the late Jurassic period]; and still more recently, that strange bird, the Archeopteryx, with a long lizard-like tail, bearing a pair of feathers on each joint, and with its wings furnished with two free claws, has been discovered in the oolitic slates of Solnhofen. Hardly any recent discovery shows more forcibly than this how little we as yet know of the former inhabitants of the world. Archaeopteryx in the 20th Century New specimens of Archaeopteryx have been discovered at regular intervals throughout the 20th century--but given our much-improved knowledge of Jurassic life, some of these dino-birds have been relegated, tentatively, to new genera and sub-species. Heres a list of the most important Archaeopteryx fossils of modern times: The Eichstatt specimen was discovered in 1951 and described almost a quarter-century later by the German paleontologist Peter Wellnhofer. Some experts speculate that this small individual actually belongs to a separate genus, Jurapteryx, or at least that it should be classified as a new Archaeopteryx species. The Solnhofen specimen, discovered in the early 1970s, was also examined by Wellnhofer after it had been misclassified as belonging to Compsognathus (a small, non-feathered dinosaur that has also been found in the Solnhofen fossil beds). Once again, some authorities believe that this specimen actually belongs to newly designated contemporary of Archaeopteryx, Wellnhoferia. The Thermopolis specimen, discovered in 2005, is the most complete Archaeopteryx fossil discovered to date and has been a key piece of evidence in the continuing debate about whether Archaeopteryx was truly the first bird, or closer to the dinosaur end of the evolutionary spectrum. No discussion of Archaeopteryx is complete without mentioning the Maxberg specimen, the mysterious fate of which sheds some light on the seamy intersection of commerce and fossil-hunting. This specimen was discovered in Germany in 1956, described in 1959, and owned privately after that by one Eduard Opitsch (who loaned it out to the Maxberg Museum in Solnhofen for a few years). After Opitsch died, in 1991, the Maxberg specimen was nowhere to be found; investigators believe that it was stolen from his estate and sold to a private collector, and it hasnt been seen since. Was There Really Only One Species of Archaeopteryx? As the above list demonstrates, the various specimens of Archaeopteryx discovered over the last 150 years have created a tangle of proposed genera and individual species that are still being sorted out by paleontologists. Today, most paleontologists prefer to group most (or all) of these Archaeopteryx specimens into the same species, Archaeopteryx lithographica, though some still insist on referring to the closely related genera Jurapteryx and Wellnhoferia. Given that Archaeopteryx has yielded some of the most exquisitely preserved fossils in the world, you can imagine how confusing it is to classify the less well-attested reptiles of the Mesozoic Era!

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