A Comparison of Traditional and Geometric Morphometric Techniques for the Study of Basicranial Morphology in Horses: A Case Study of the Araucanian Horse from Colombia.
Abstract: Skull size and shape have been widely used to study domestic animal populations and breeds. Although several techniques have been proposed to quantify cranial form, few attempts have been made to compare the results obtained by different techniques. While linear morphometrics has traditionally been used in breed characterization, recent advances in geometric morphometrics have created new techniques for specifically quantifying shape and size. The objective of this study was to compare two morphometric methods for their ability to describe external morphology. For this purpose, 20 skull specimens of adult male Araucanian horses were examined. Two age categories were established (the "mature group", M not fully erupted to moderately worn, = 7; and the "senile group", M totally erupted and highly worn, = 13). Both methods showed that there were statistical differences between generations, but discrimination rates were different between methods with the geometric morphometric analysis obtaining a rate of 97.5%. Although linear morphometrics was found to be compatible with geometric morphometrics, the latter was better able to discriminate the two groups and it also provides more information on shape.
Publication Date: 2020-01-10 PubMed ID: 31936822PubMed Central: PMC7022957DOI: 10.3390/ani10010118Google Scholar: Lookup
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Summary
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This research compares traditional and modern techniques for measuring the shape and size of horse skulls. The researchers found that both methods are successful in differentiating between age groups, but the new technique, geometric morphometrics, is more precise.
Introduction to Studying Skull Morphology
- The study compared two different techniques for quantifying the shape and size of horse skulls: traditional linear morphometrics and a more recent advance, geometric morphometrics. Both of these are widely used in studying domestic animal breeds.
- By examining the form of skulls, researchers can get insights into breed characteristics. However, there has been little research comparing the results obtained from different quantifying methods.
- The researchers used 20 skull specimens of adult male Araucanian horses from Colombia for their study.
Comparing Techniques in Different Age Groups
- The researchers divided the 20 Araucanian horse specimens into two age groups. The “mature group” consisted of horses whose molars (“M”) were not fully erupted or moderately worn, and the “senile group” contained horses whose molars were totally erupted and highly worn.
- The purpose of this study was to test the effectiveness of the two measurement methods in describing external morphology, and more specifically, in differentiating between the two different age categories.
Results and Implications
- Both techniques proved successful in identifying statistical differences between the two age categories, demonstrating their utility in such breed characterization studies.
- However, discrimination rates (which measure the ability to accurately distinguish between groups) differed between the two methods. Geometric morphometrics achieved a 97.5% discrimination rate, significantly higher than linear morphometrics.
- While the traditional linear morphometrics technique was compatible with geometric morphometrics, the study found geometric morphometrics to be more effective in discriminating between the groups. Moreover, geometric morphometrics also provides more information about the shape of the specimens.
- The conclusion is that while traditional methods are still useful, geometric morphometrics might be a more precise tool for studying skull morphology in horses and possibly other domestic animals.
Cite This Article
APA
Parés-Casanova PM, Salamanca-Carreño A, Crosby-Granados RA, Bentez-Molano J.
(2020).
A Comparison of Traditional and Geometric Morphometric Techniques for the Study of Basicranial Morphology in Horses: A Case Study of the Araucanian Horse from Colombia.
Animals (Basel), 10(1), 118.
https://doi.org/10.3390/ani10010118 Publication
Researcher Affiliations
- Departament de Ciència Animal, ETSEA, Universitat de Lleida, 25198 Lleida, Spain.
- Grupo de Investigaciones los Araucos, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia, Arauca 810001, Colombia.
- Grupo de Investigaciones los Araucos, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia, Arauca 810001, Colombia.
- Grupo de Investigaciones los Araucos, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia, Arauca 810001, Colombia.
Grant Funding
- INV2378-I / Universidad Cooperativa de Colombia
Conflict of Interest Statement
The authors declare that there are no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
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Citations
This article has been cited 2 times.- Turner GF, Crampton DA, Rusuwa B, Hooft van Huysduynen A, Svardal H. Taxonomic investigation of the zooplanktivorous Lake Malawi cichlids Copadichromis mloto (Iles) and C. virginalis (Iles).. Hydrobiologia 2023;850(10-11):2165-2175.
- Wikantyoso B, Tseng SP, Himmi SK, Yusuf S, Yoshimura T. Morphometric Analysis of Coptotermes spp. Soldier Caste (Blattodea: Rhinotermitidae) in Indonesia and Evidence of Coptotermes gestroi Extreme Head-Capsule Shapes.. Insects 2021 May 20;12(5).
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