Question

The connecting link between aves and reptiles is_____

Answer 1

-Connecting links are known to be organisms that have characteristics of two different adjacent taxonomic groups. These organisms are important since they give us an idea about the evolution of organisms of both the groups.

Complete answer-
The connecting link between aves and reptiles is Archaeopteryx since it has many avian and non-avian dinosaur-like characteristics. They belong to the clade Dinosauria and are known to have existed during the late Jurassic period. Till date twelve specimens of Archaeopteryx have been discovered, the first one known as London Specimen was found in the year 1861 near Langenaltheim, Germany. Characters similar to reptiles and aves are given below.
Few of the reptilian features of archaeopteryx are-

1. Presence of a long tail
2. The jaws are similar to that of reptiles
3. Free caudal vertebrae like that of lizards are present
4. They have weak sternum resembling that of reptiles
5. The hand is more like reptilian type ending in a claw
   Few of the avian characteristic are-
6. Presence of feathers on the body like birds
7. Presence of beak
8. The forelimbs are modified to form wings
9. Fusion of the skull bone like that found in birds is found
10. The hind limbs resembles those of the avian type

Note-
Thus due to the presence of many characters similar to both reptiles and aves Archaeopteryx is considered to be a connecting or missing link, many species of Archaeopteryx have been discovered from the fossils, the most prevalent being Archaeopteryx lithographica.