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Archaeopteryx

Archaeopteryx

Archaeopteryx

Archeopteryx is an extinct bird 150 million years ago. It is a species of toothed bird that combines the characteristics of reptiles and the characteristics of birds. Therefore, it is considered one of the intermediate links between the class of birds and reptiles. It is the first bird to show feathers in its body.

The extinct bird, a genus of Archeopteryx from the Jurassic period, had lizard-like characteristics such as teeth, and a long, bony tail. It represents a transitional form between dinosaurs and birds. The oldest fossilized animal is known as a bird. The bird lived during the late Jurassic period, 159 to 144 million years ago. Fossil models indicate that Archaeopteryx ranged in size from as small as a blue fowl to as large as a chicken. Archeopteryx had similar characteristics to birds such as well-developed wings and an avian skull.

The fossil of Archaeopteryx was found in 1860 and described the following year in Bavaria. All ten fossils (nine skeletons and one feather) that were found for him between the years 1860 and 1992 were found in an area of ​​​​1336 km² in Solnhofen, a town in Bavaria in the southeast of Germany. it is classified as bird because of feathers, legs and wings. Its size is about the size of a dove. It is still debated whether it was an arboreal or terrestrial bird that could not fly very well. He also announced the existence of a fossil bird in West Texas in the year 1983 called Protoavis, a primitive bird also believed to have preceded Archaeopteryx by about 75 million years.

Archeopteryx lived during the late Upper Jurassic period, about 150 million years ago, in what became southern Germany during a time when Europe was an archipelago of islands in a warm, shallow tropical sea, much closer to the equator than it is now. Archeopteryx was about the size of the Eurasian magpie, but large numbers of it reached the size of a crow. [4] The largest species of Archeopteryx can grow up to 0.5 m (1 ft 8 in) in length. Despite its small size, broad wings, and ability to fly or glide, Archeopteryx had more in common with small, medium-sized dinosaurs than with modern birds. In particular, Archeopteryx shares the following features with Dromaeosaurus and Troodontids:

These features make Archeopteryx an obvious candidate for transitional fossils between non-avian dinosaurs and birds. Thus, Archeopteryx plays an important role, not only in the study of the origin of birds, but also in the study of dinosaurs. In 1861, the first complete specimen of Archeopteryx was reported. Ten more Archeopteryx fossils have turned up over the years. Despite the difference between these fossils, most experts consider all the remains that were discovered to belong to one species, but this topic is still a matter of debate until now.

Most of these eleven fossils include feather imprints. These fossils are considered evidence that the evolution of feathers began before the Upper Jurassic period, because the feathers found within these fossils were an advanced form of (flight feathers). The typical Archeopteryx was discovered just two years after Charles Darwin published his book On the Origin of Species. Archeopteryx emerged as a validator of Darwin's theories and has since become a key piece of evidence for the origin of birds, discussion of transitional fossils, and confirmation of evolution.

In March 2018, scientists announced that Archeopteryx was able to fly, but in a manner completely different from that of modern birds.


excavation sites

The first discovery of a dinosaur bird was in Sollenhofen in southern Germany in 1861. Discoveries followed in many regions in Germany, in Eichstedt, Langen-Altheim and Jachenhausen. It was also found in Portugal in a coal mine called the “Jimarota Mine” near the city of Leiria. This type of Saurian animal lived in the Jurassic period - that is, 151 to 145 million years ago.


the description

Most of the Archeopteryx specimens that have been discovered come from the limestone of the village of Solnhofen in Bavaria, located in southern Germany, and it is a rare and noteworthy sedimentary geological formation, known for its uniquely detailed fossils that formed during the early Tetonian phase of the Upper Jurassic period, that is, about 150.8 to 148.5 million years ago. year.

Archeopteryx was about the size of a crow, with broad, rounded wings, and a long tail compared to its body length. Its body can reach a length of 500 millimeters (20 in), with an estimated mass of 0.8 to 1 kilogram (1.8 to 2.2 lb). The plumage of Archeopteryx, though less documented than its other distinguishing features, is very similar in structure to that of modern-day birds. Although Archeopteryx possessed many of the features of birds, it had many of the characteristics of non-avian dinosaurs. Unlike modern birds, Archeopteryx had small teeth, as well as a long, bony tail, features that Archeopteryx shared with other dinosaurs of the time.

Having features common to both birds and non-avian dinosaurs alike, Archeopteryx has often been considered a link between the two. John Ostrom argued in the 1970s, following the initiative of Thomas Henry Huxley in 1868, that birds evolved within the family of theropod dinosaurs and that Archeopteryx was crucial evidence for this argument; Archeopteryx contained many of the features of birds, such as wishbones, flight feathers, wings, and a partially turned first toe (thumb), along with features of dinosaurs and theropods. For example, it has a long ascending process of the talus, interdental plates, a petrous process of the hip bone, and long bars in the tail. Ostrom found that Archeopteryx was remarkably similar to the dromaeosaurids of the theropod family.


bird feathers

The discovered specimens of Archeopteryx are widely known for their well-developed and distinctly asymmetric flight feathers, and had flight feather structures similar to those of modern birds, with a fan-shaped shape providing stability through a barb-barbule-barbicel arrangement. The tail feathers of Archeopteryx were less divergent, similar to those of modern birds, and took the form of stiff fan feathers, the thumb of Archeopteryx had not yet emerged as a separate moving tuft of stiff feathers.

The body feathers of Archeopteryx are not well documented and have only been fully studied in the well-preserved Berlin specimen. Thus, since more than one species appears to be involved, the study of the Berlin specimen's feathers cannot necessarily apply to the rest of Archeopteryx. The Berlin specimen bore "trousers" of developed feathers on the legs. Some of these feathers appear to have the structure of a circumipolar feather (small feathers at the body borders of adult birds), but are somewhat degenerate (lacking barbicels as in ratites or flightless birds). Some are hard and rigid and therefore capable of supporting flight.


dissenting point of view

Avian evolutionist Alan Feduccia presented a theory contrary to the common hypothesis that Archeopteryx was the ancestor of birds and a transitional fossil between dinosaurs and birds, and wrote this down in his book (The Origin and Evolution of Birds) and in a number of researches in ornithological journals.

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