Chapter 27, Problem 1RQ

Explain the significance of the discovery of Archaeopteryx. Why did this fossil demonstrate beyond reasonable doubt that birds are grouped phylogenetically with dinosaurs?

Summary Introduction

To describe: The significance of the discovery of Archaeopteryx.

Introduction: Archaeopteryx refers to the genus of bird-like dinosaurs, which lived in the Late Jurassic around 150 million years ago. It had a size of about one foot and eight inches.

Explanation of Solution

Archaeopteryx fossil was discovered by the workman in the year 1861. Its fossil was a fortunate discovery as the fossil records of birds were meager. It also serves as the fossil proof for demonstrating the phylogenetic relationships between the birds and the extinct theropod dinosaurs.

Summary Introduction

To explain: The reason due to which the fossil of Archaeopteryx demonstrated beyond reasonable doubt for the phylogenetic grouping of birds with dinosaurs.

Introduction: The term phylogeny refers to the evolution of a species in the context of its ancestry and its evolutionary relationship with other organisms. Archaeopteryx is considered as the connecting link which explains the phylogenetic relation between birds and dinosaurs. Currently, birds are considered to be a group of theropod dinosaurs which originated in the Mesozoic Era.

Explanation of Solution

The size of the fossil of Archaeopteryx was approximately of the size of a crow. It had a skull which was not similar to that of the modern birds and a beak-like jaw which bore small bony teeth set in sockets, like those observed in dinosaurs. Its skeleton was reptilian with a long bony tail, clawed fingers and abdominal ribs and its body also carried the imprint of feathers.

These features observed in the fossil of Archaeopteryx, demonstrate the phylogenetic relation between birds and dinosaurs.