🧑🏻‍🏫 متنی که در وبینار قرار هست بررسی کنیم رو اینجا قرار میدم. لطفا قبل از شروع وبینار این متن رو مطالعه کنید تا اگه سوالی بود بتونید مطرح کنید:

While it may be difficult to see any similarities between the giant skeletal remains of a dinosaur and the eagle that soars above us, many scientists believe that the two are distant relatives.

The link between reptiles and birds is thought by many to be in the form of a crow-sized creature that existed some 160 million years ago. In 1861, the fossil of a “dinosaur” with wings was discovered on the bottom of a limestone quarry in Bavaria. While the skeleton appeared reptilian, its shoulder girdle, pelvis, and legs were similar to those of modern-day birds, so the scientists called it Archaeopteryx, from the Greek words for “ancient,” “wing,” and “written in stone.” The most startling discovery, however, was that Archaeopteryx had feathers, apparently exactly like those found on birds today. Although it is not known whether the creature could fly (some scientists believe it could only glide), the development of feathers was a crucial step in the evolution of what we today know as birds.

Detractors of this theory point out that Archaeopteryx cannot be used to link the reptile and bird worlds because there is little evidence establishing Archaeopteryx as a true reptile. Nor is there evidence showing a progression from the scales of reptiles to the fathers found in Archaeopteryx and those that adorn today’s birds. Any evidence along these lines has been particularly difficult to obtain because birds rarely die, as Archaeopteryx so conveniently did, in situations favorable to the preservation of their delicate bodies and thin, light skeletons.

There is no question, however, that birds and reptiles possess some of the same characteristics. Ancient bird and reptile fossils had similar skulls, neck vertebrae, ribs, bones, brains, eyes, blood, and eggs. Both groups had scales, and modern reptiles have scales, as do the legs of today’s birds. Both modern birds and reptiles lay eggs that allow their embryos to develop and hatch out of water. During the hatching process, the young in both groups are aided by an egg tooth, used to break the shell of the egg from the inside.