Scientists have discovered new details about the structural materials that form the horn and the role those materials play in the development of the horn’s characteristic shape.
The horns of most animals have a bony core covered by a thin sheath of keratin, the same substance as hair and nails. Rhino horns are unique, however, because they are composed entirely of keratin. Scientists had been puzzled by the difference, but the Ohio University study now has revealed an interesting clue: dark patches running through the center of the horns.
The team examined the heads of rhinos that died of natural causes and were donated by The Wilds in Cumberland, Ohio, and the Phoenix Zoo. Researchers conducted CT scans on the horns at O’Bleness Memorial Hospital in Athens and found dense mineral deposits made of calcium and melanin in the middle.
The calcium deposits make the horn core harder and stronger, and the melanin protects the core from breakdown by the sun’s UV rays, the scientists report. The softer outer portion of the horn weakens with sun exposure and is worn into its distinctive shape through horn clashing and by being rubbed on the ground and vegetation. The structure of the rhino horns is similar to a pencil’s tough lead core and weaker wood periphery, which allows the horns to be honed to a sharp point.
The study also ends speculation that the horn was simply a clump of modified hair.
“The horns most closely resemble the structure of horses’ hoofs, turtle beaks and cockatoo bills. This might be related to the strength of these materials, although more research is needed in this area,” said Tobin Hieronymus, a doctoral student in biological sciences and lead author on the study.
The study also found that the melanin and calcium patches appear in yearly growth surges but the effects of temperature, diet and stress on the growth are still unknown. The results of the horn growth study may be of interest to conservation groups whose goal is to strengthen rhino populations and reduce the poaching of horn for the black market.
“Ultimately, we think our findings will help dispel some of the folk wisdom attached to the horn. The more we can learn about the horn, the better we can understand and manage rhino populations in the wild and in captivity,” said Lawrence Witmer, a professor of anatomy in Ohio University’s College of Osteopathic Medicine and director of the project.
The Journal of Morphology published the research findings in its October issue. Witmer and Ryan Ridgely were co-authors of the study, which was funded by the National Science Foundation and conducted with the assistance of O’Bleness Memorial Hospital in Athens, Ohio, and The Wilds, an Ohio animal preserve.
Andrea Gibson | EurekAlert!
The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung
A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg
A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
24.01.2017 | Physics and Astronomy
24.01.2017 | Life Sciences
24.01.2017 | Health and Medicine