It is often hard to believe, but indeed it’s the most correct notion as per our current understandings that birds are the living modified descendants of dinosaurs! The concept of ‘descent with modification’, an extraordinary idea the scientific world has ever seen came from the revolutionary naturalists and scientists C. R. Darwin and A. R. Wallace. I wonder! What an exciting moment it was for both Darwin and Wallace when the fossil of Archaeopteryx was described at their own lifetime which clearly shows a giant piece of evidence in favor of their scientific idea on the origin and diversification of living beings on earth! I became speechless, and numb and steadily set my eyesight upon this magnificent fossil replica of Archaeopteryx while I first saw it in the Indian Museum, Kolkata. Not because this fossil represents the transitional stage in birds’ evolution since there are numerous discoveries of transitional fossils of various groups of animals, but because Archaeopteryx is one of the most debated fossils of all time!
Replica of Archaeopteryx siemensii, the Berlin Specimen from Indian Museum, Kolkata
During 1860-1861, two fossilized remnants of some extinct animals were unearthed from the upper Jurassic lithographic limestone in Germany. One of these specimens was the fossilized remnant of a single feather while the other (commonly known as the London specimen) was a fossilized body of some unknown feathered animal missing most of its head and neck. In 1862, Christian Erich Hermann von Meyer, a German palaeontologis described the feather specimen as Archaeopteryx lithographica and mistakenly concluded that this feather might not have been from the same animal as the body fossil, but from some undiscovered avialans! Later on, in 1863 one of the major rivals of Darwin during his lifetime, Richard Owen, concluded that the body fossil does certainly belong to the same group as like the feather fossil, but represents an another species, hence he described it as Archaeopteryx macrura. Though the morphology of Archaeopteryx varies greatly and distinctly from those of modern birds, Owen, the stubborn opponent of Darwin’s idea refuted the claim of Archaeopteryx as being a transitional fossil! Owen instead compared the Archaeopteryx fossil morphology with those of modern day Raptor, Passerines, and Galliformes birds and concluded that this animal rather represents some extinct lineage of bird! This was merely a biased speculation, neither Owen, nor his idea is correct from the scientific viewpoint. Hugh Falconer, a Scottish geologist and paleontologist, saw the Archaeopteryx as certainly a valid ‘transitional’ fossil and pointed out that Owen’s description of the Archaeopteryx had missed some essential elements. On January 3, 1863, he wrote a letter to Darwin about the significance of this fossil: “It is a much more astounding creature—than has entered into the the conception of the describer (Owen)—who compares it with the Raptores & Passeres & Gallinaceæ, as a round winged (like the last) `Bird of flight.’ It actually had at least two long free digits to the fore limb—and those digits bearing claws as long and strong as those on the hind leg. Couple this with the long tail—and other odd things,—which I reserve for a jaw—and you will have the sort of misbegotten-bird-creature—the dawn of an oncoming conception `a la Darwin.” Darwin answered that letter on January 20, 1863, and commented about Owen’s mistake: “Has God demented Owen, as a punishment for his crimes, that he should overlook such a point?” Stubborn people with heads filled in unscientific ideas like Owen are still there shouting like daft, but their shouting can hardly cause any impact in science! Till date twelve body fossil specimens of Archaeopteryx and the feather one have been described. All of these come from the upper Jurassic lithographic limestone deposits, quarried for centuries, near Solnhofen, Germany. The specimens are:
· The feather · The London specimen · The Berlin specimen · The Maxberg specimen · The Haarlem specimen · The Eichstätt specimen · The Solnhofen specimen · The Munich specimen · The Daiting specimen · The Bürgermeister-Müller specimen · The Thermopolis specimen · The eleventh specimen · The twelfth specimen
The replica from the Indian museum, is actually a replica of the Berlin specimen that was discovered during 1874-75 at the Blumenberg quarry near Eichstätt, Germany, by farmer Jakob Niemeyer, who reportedly sold the fossil for the money to buy a cow around a year later, to inn-keeper Johann Dörr, who again sold it to Ernst Otto Häberlein, the son of K. Häberlein. Placed on sale between 1877 and 1881, with potential buyers including O. C. Marsh of Yale University's Peabody Museum, it was eventually bought by the Natural History Museum of Berlin, where it is now displayed. It is the most complete specimen, and the first with a complete head. It was named in 1897 by Dames as a new species, A. siemensii; a 2002 evaluation supports the A. siemensii species identification. (The labelling in Indian Museum as Archaeopteryx lithographica is hence incorrect).
Currently, there are five major hypotheses among scientists regarding the origin of birds. However, most scientists favor for the idea that Archaeopteryx was the stem lineage on the way towards modern birds.
Whatever the view one holds, birds are indeed the glorified reptiles!
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