Archaeopteryx
by Thomas M.
The Archaeopteryx was one of the most puzzling animals to ever walk the face of the earth. When its first fossil was found in Germany, it appeared to be a small bird, about 1 ft. in length with imprints of feathers. However, closer inspection reveals that it was more closely related to the lizard family. Evidence that supports this theory is that the Archaeopteryx had teeth and a long tailbone, two traits that modern-day birds don’t have.
According to evolution, all animals evolved from a single common ancestor, gaining different traits throughout time. These sets of traits help to define an individual species. During the beginning of the Archaeopteryx’s evolutionary journey according to our cladogram, it started by evolving a skull and backbone (the trait found in all vertebrates), allowing better mobility and cranial protection. Next, the soon-to-be Archaeopteryx became a gnathostome, meaning it gained a jaw. Soon, it became a tetrapod, receiving 4 legs, which increased its mobility. After, the Archaeopteryx gained watertight eggs, allowing it to lay eggs on land without fear of them drying up. This made it an amniote. Next, it evolved a pair of palatal openings, which gave blood vessels and nerves better access. This made the Archaeopteryx a sauropsid. After, the Archaeopteryx gained a hole in its hip sockets, allowing an upright posture. This trait defined it as a dinosaur. The saurischian grasping hand that came next gave it the ability to hold onto vital objects. The 3-toed foot of the theropods allowed rapid movement, and, finally, a pulley-shaped wrist bone, the mark of a maniraptor, gave the Archaeopteryx greater hand flexibility.
Archaeopteryx is related to many diverse animals. However, it seems to be most closely related to the seagull on our cladogram, due to them both being maniraptors, animals with a pulley-shaped wrist bone. However, while the Archaeopteryx has teeth, the seagull does not. A cladogram can be used to get this information because the Archaeopteryx and the seagull meet up first on the cladogram before they do with any other animal, and maniraptors are the smallest, most exclusive group that includes both animals.
Last updated April 7, 2007.