The Elements of Evolution (23-2-3) Archaeopteryx


The raven-sized Archaeopteryx lived 150 MYA, during the Late Jurassic. It was a bird-like dinosaur, with 2 feathered wings.

Archaeopteryx had jaws lined with small sharp teeth, 3 fingers ending in curved claws, and a long bony tail; traits shared with its dinosaur cousins. While these features would be forsaken by its avian descendants, Archaeopteryx had some bird-like traits.

Birds need a sophisticated sensory system to quickly process the flood of visual information that comes during flight, integrated to a complex mapping system. Archaeopteryx had a broad cerebellum, indicative of heavily relying on vision.

Archaeopteryx had a larger relative braincase than dinosaurs. The structure of its inner ear more closely resembled modern birds than reptiles. Archaeopteryx appears to have keen senses of hearing, balance, spatial perception, and coordination; the processing perquisites of flight. Whether and how well Archaeopteryx actually flew remains speculative. Its long tail precluded taking off from the ground.

The fingers on Archaeopteryx‘s wings would have interrupted smooth airflow but they would have been essential in climbing up trees.

Archaeopteryx may have glided decently. Its feathered wings suggest modest flight capability. Albeit distinctive, Archaeopteryx had pennaceous feathers like modern birds. Though the feather structure was weak by modern standards, Archaeopteryx had matt black plumage.

In modern birds, black melanin pigment substantially increases the strength and durability of feathers. ~ American paleontologist Ryan Carney

Archaeopteryx showed no sign of the structures in modern birds that prevent twisting of the spine during flight. One of least bird-like features of Archaeopteryx was its spinal column and rather small hipbones.

If Archaeopteryx did take to the air, its lack of a large breastbone suggests that it was not a strong flier; perhaps able to fly in short bursts, like modern pheasants. Nonetheless, its wing muscles, however inadequate for sustaining powered flight, were attached to a thick, boomerang-shaped wishbone, which was a bird-like feature.

Although Archaeopteryx is accepted as the earliest bird, it is becoming difficult to see it as much more than another feathered dinosaur. In many ways, Archaeopteryx was just another small, scurrying ground dweller. ~ Canadian evolutionary biologist Gary Kaiser