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Published on: October 15, 2019
The early evolution of the tetrapod humerus.
Neil H Shubin1, Edward B Daeschler, Michael I Coates
1Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA. nshubin@uchicago.edu
Science (New York, N.Y.)
|April 6, 2004
Summary
Early tetrapod limbs evolved from fish fins, not independently. This study reveals limb function in body support originated in fish fins, showcasing early appendage diversity despite conserved humeral architecture.
Area of Science:
- Paleontology
- Evolutionary Biology
- Comparative Anatomy
Background:
- The evolution of tetrapod limbs from fish fins is a pivotal event in vertebrate history.
- Understanding the functional morphology of early limbs is key to reconstructing terrestrial locomotion origins.
Purpose of the Study:
- To analyze a novel tetrapod humerus fossil from the Late Devonian of Pennsylvania.
- To investigate the evolutionary origins of limb function in body support.
- To explore the diversity of early limb designs and humeral architecture.
Main Methods:
- Comparative analysis of the fossil humerus with other Devonian humeri.
- Functional morphology assessment of limb roles in body support.
Main Results:
- The fossil humerus exhibits a unique combination of primitive and derived traits.
- Evidence suggests limb function for body propping originated in fish fins, predating tetrapod limbs.
- Early tetrapod appendages displayed significant functional diversity in design.
Conclusions:
- The origin of body-propping function lies within fish fins.
- Early tetrapod limb evolution was characterized by diverse appendage designs.
- Humeral architecture remained conserved throughout the Devonian, facilitating functional diversification.
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