The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Pascal Tassy - One of the best experts on this subject based on the ideXlab platform.
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Elephants and other Proboscideans: a summary of recent findings and new taxonomic suggestions
2020Co-Authors: Jeheskel Shoshani, William J. Sanders, Pascal TassyAbstract:SUMMARY: Today we recognize 165 species and subspecies of proboscideans, classified in 42 genera and 8 families. Of these, three species are extant: the forest African elephant (Loxodonta cyclotis), bush African elephant (L. africana), and the Asian elephant (Elephas maximus, with three subspecies). In 2000, the estimated world population of elephants was just over one half million; most are African elephants. New taxa include Mammutida and Elephantida, and one proposed here: Plesielephantiformes, as a sister taxon to Elephantiformes. Neontological research is currently under way on these areas of investigation: anatomy and physiology on eye, trunk, Hyoid Apparatus, brain, hearing, reproduction, ecology, behavior, and conservation. Topics for future research include: phylogenetic positions of Anthracobunids, Moeritherium, tetralophodont gomphotheres, Stegolophodon and Stegodon, and intra-familial relationships among Loxodonta, Elephas and Mammuthus, and also continuing studies on brain, reproductive biology, and conservation, emphasizing educational approaches.
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advances in proboscidean taxonomy classification anatomy physiology and ecology behavior
Quaternary International, 2005Co-Authors: Jeheskel Shoshani, Pascal TassyAbstract:Abstract With the addition of 13 new taxa, we recognized 175 species and subspecies of proboscideans, classified in 42 genera and 10 families. The three extant species are: forest African elephant (Loxodonta cyclotis), bush African elephant (L. africana), and Asian elephant (Elephas maximus, with three subspecies). Rigorous analysis of characters published or awaiting publication is imperative for better understanding of the cladistic relationships among currently recognized proboscideans. Here we focus on “aquatic ancestry” of Proboscidea, interordinal relationships within Placentalia, proboscidean taxonomy in general and South American in particular, anatomy and physiology and some ecological considerations. New taxa above the family level include sister taxa Mammutida and Elephantida, and Plesielephantiformes as a sister taxon to Elephantiformes. Neontological research is currently under way on the Hyoid Apparatus, lungs, brain, hearing, ecology and behavior. Topics for future research include: phylogenetic positions of anthracobunids, Moeritherium, tetralophodont gomphotheres, Stegolophodon and Stegodon, and intra-familial relationships among Loxodonta, Elephas and Mammuthus, and continuing studies on encephalization quotient. Certain anatomical features and functions (e.g., the Hyoid Apparatus that helps in food procurement, in production of infrasonic sounds, and in storing water to be used in time of stress) evolved about 25 million years ago, in time for diversification into new niches when grasses appeared in the landscape.
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Advances in proboscidean taxonomy & classification, anatomy & physiology, and ecology & behavior
Quaternary International, 2004Co-Authors: Jeheskel Shoshani, Pascal TassyAbstract:Abstract With the addition of 13 new taxa, we recognized 175 species and subspecies of proboscideans, classified in 42 genera and 10 families. The three extant species are: forest African elephant (Loxodonta cyclotis), bush African elephant (L. africana), and Asian elephant (Elephas maximus, with three subspecies). Rigorous analysis of characters published or awaiting publication is imperative for better understanding of the cladistic relationships among currently recognized proboscideans. Here we focus on “aquatic ancestry” of Proboscidea, interordinal relationships within Placentalia, proboscidean taxonomy in general and South American in particular, anatomy and physiology and some ecological considerations. New taxa above the family level include sister taxa Mammutida and Elephantida, and Plesielephantiformes as a sister taxon to Elephantiformes. Neontological research is currently under way on the Hyoid Apparatus, lungs, brain, hearing, ecology and behavior. Topics for future research include: phylogenetic positions of anthracobunids, Moeritherium, tetralophodont gomphotheres, Stegolophodon and Stegodon, and intra-familial relationships among Loxodonta, Elephas and Mammuthus, and continuing studies on encephalization quotient. Certain anatomical features and functions (e.g., the Hyoid Apparatus that helps in food procurement, in production of infrasonic sounds, and in storing water to be used in time of stress) evolved about 25 million years ago, in time for diversification into new niches when grasses appeared in the landscape.
Joanna Mckittrick - One of the best experts on this subject based on the ideXlab platform.
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structural analysis of the tongue and Hyoid Apparatus in a woodpecker
Acta Biomaterialia, 2016Co-Authors: Jaeyoung Jung, Steven E Naleway, Nicholas A Yaraghi, Steven Herrera, Vincent R Sherman, Eric A Bushong, Mark H Ellisman, David Kisailus, Joanna MckittrickAbstract:Abstract Woodpeckers avoid brain injury while they peck at trees up to 20 Hz with speeds up to 7 m/s, undergoing decelerations up to 1200 g. Along with the head, beak and neck, the Hyoid Apparatus (tongue bone and associated soft tissues) is subjected to these high impact forces. The shape of the Hyoid Apparatus is unusual in woodpeckers and its structure and mechanical properties have not been reported in detail. High-resolution X-ray micro-computed tomography and scanning electron microscopy with energy dispersive X-ray spectroscopy were performed and correlated with nanoindentation mapping. The Hyoid Apparatus has four distinct bone sections, with three joints between these sections. Nanoindentation results on cross-sectional regions of each bone reveal a previously unreported structure consisting of a stiff core and outer, more compliant shell with moduli of up to 27.4 GPa and 8.5 GPa, respectively. The bending resistance is low at the posterior section of the Hyoid bones, indicating that this region has a high degree of flexibility to absorb impact. These new structural findings can be applied to further studies on the energy dissipation of the woodpecker during its drumming behavior, and may have implications for the design of engineered impact-absorbing structures. Statement of Significance Woodpeckers avoid brain injury while they peck at trees, which results in extreme impact conditions. One common adaptation in woodpeckers is the unusual shape of the elongated tongue, also called the Hyoid Apparatus. The relationship between the structure and mechanical properties of the bony part of the Hyoid Apparatus has not been previously reported. A three dimensional model of the bony tongue was developed, and the hardness and stiffness were evaluated. A new type of bone structure, which is opposite of typical skeletal bone structure was found. The combined microstructural and mechanical property analysis indicate possible energy absorption routes for the Hyoid Apparatus and are applicable to the design of engineered structures.
Roderick A Suthers - One of the best experts on this subject based on the ideXlab platform.
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an animated 3d model of the synchronous movements of the suprasyringeal structures and organs in the neck of a vocalizing songbird the northern cardinal cardinalis cardinalis 918 8
The FASEB Journal, 2014Co-Authors: Caroline E Blevins, Jinghua Ge, Roderick A Suthers, Dominique G HombergerAbstract:In birds, sound is generated in the syrinx and is filtered by suprasyringeal structures that move relative to one another. The larynx moves relative to the Hyoid Apparatus, which moves relative to ...
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Modulation of birdsong by resonance filters in the suprasyringeal vocal tract.
Journal of the Acoustical Society of America, 2009Co-Authors: Roderick A SuthersAbstract:The sound generated in the avian vocal organ, the syrinx, is modified by the filter properties of the upper vocal tract before it radiates from the beak as song. Previous investigators have shown that the properties of this vocal tract filter are affected by changes in beak gape, but the basis of this effect remains controversial. In the present study, x‐ray cinematography of singing birds was used to investigate the filter properties of the suprasyringeal vocal tract. These experiments show that the dimensions of the oropharynx and esophagus are actively controlled during song by motor patterns involving muscles of the Hyoid Apparatus. These song‐related motor patterns, together with movements of the tongue, which modulate the opening from the mouth into the beak, adjust in real time the volume and dimensions of the oropharynx and cervical esophagus so that the primary acoustic resonance of the upper vocal tract supports and tracks the fundamental frequency that is being generated by the syrinx. In juven...
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Birdsong: The role of the vocal tract
Journal of the Acoustical Society of America, 2006Co-Authors: Roderick A SuthersAbstract:The avian vocal organ, the syrinx, is unique among vertebrates in its morphology and location at or near the base of the trachea. In oscine songbirds, two independent sound sources share the same vocal tract. Despite a growing knowledge of the neural and syringeal mechanisms underlying song, the acoustic role of the suprasyringeal vocal tract in modulating birdsong is still poorly understood. During song, the beak opening, or gape, is typically positively correlated with the dominant frequency of the vocalization, but the mechanism by which beak gape influences vocal tract acoustics is controversial. X‐ray cinematography of singing birds reveals song‐related movements of the Hyoid Apparatus and larynx that cause the volume of the upper vocal tract to vary inversely with the songs fundamental frequency. At low fundamental frequencies, the oropharynx and cranial end of the esophagus expand to form a single large chamber, the volume of which is reduced at higher frequencies by collapse of the esophagus and r...
Jeheskel Shoshani - One of the best experts on this subject based on the ideXlab platform.
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Elephants and other Proboscideans: a summary of recent findings and new taxonomic suggestions
2020Co-Authors: Jeheskel Shoshani, William J. Sanders, Pascal TassyAbstract:SUMMARY: Today we recognize 165 species and subspecies of proboscideans, classified in 42 genera and 8 families. Of these, three species are extant: the forest African elephant (Loxodonta cyclotis), bush African elephant (L. africana), and the Asian elephant (Elephas maximus, with three subspecies). In 2000, the estimated world population of elephants was just over one half million; most are African elephants. New taxa include Mammutida and Elephantida, and one proposed here: Plesielephantiformes, as a sister taxon to Elephantiformes. Neontological research is currently under way on these areas of investigation: anatomy and physiology on eye, trunk, Hyoid Apparatus, brain, hearing, reproduction, ecology, behavior, and conservation. Topics for future research include: phylogenetic positions of Anthracobunids, Moeritherium, tetralophodont gomphotheres, Stegolophodon and Stegodon, and intra-familial relationships among Loxodonta, Elephas and Mammuthus, and also continuing studies on brain, reproductive biology, and conservation, emphasizing educational approaches.
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advances in proboscidean taxonomy classification anatomy physiology and ecology behavior
Quaternary International, 2005Co-Authors: Jeheskel Shoshani, Pascal TassyAbstract:Abstract With the addition of 13 new taxa, we recognized 175 species and subspecies of proboscideans, classified in 42 genera and 10 families. The three extant species are: forest African elephant (Loxodonta cyclotis), bush African elephant (L. africana), and Asian elephant (Elephas maximus, with three subspecies). Rigorous analysis of characters published or awaiting publication is imperative for better understanding of the cladistic relationships among currently recognized proboscideans. Here we focus on “aquatic ancestry” of Proboscidea, interordinal relationships within Placentalia, proboscidean taxonomy in general and South American in particular, anatomy and physiology and some ecological considerations. New taxa above the family level include sister taxa Mammutida and Elephantida, and Plesielephantiformes as a sister taxon to Elephantiformes. Neontological research is currently under way on the Hyoid Apparatus, lungs, brain, hearing, ecology and behavior. Topics for future research include: phylogenetic positions of anthracobunids, Moeritherium, tetralophodont gomphotheres, Stegolophodon and Stegodon, and intra-familial relationships among Loxodonta, Elephas and Mammuthus, and continuing studies on encephalization quotient. Certain anatomical features and functions (e.g., the Hyoid Apparatus that helps in food procurement, in production of infrasonic sounds, and in storing water to be used in time of stress) evolved about 25 million years ago, in time for diversification into new niches when grasses appeared in the landscape.
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Advances in proboscidean taxonomy & classification, anatomy & physiology, and ecology & behavior
Quaternary International, 2004Co-Authors: Jeheskel Shoshani, Pascal TassyAbstract:Abstract With the addition of 13 new taxa, we recognized 175 species and subspecies of proboscideans, classified in 42 genera and 10 families. The three extant species are: forest African elephant (Loxodonta cyclotis), bush African elephant (L. africana), and Asian elephant (Elephas maximus, with three subspecies). Rigorous analysis of characters published or awaiting publication is imperative for better understanding of the cladistic relationships among currently recognized proboscideans. Here we focus on “aquatic ancestry” of Proboscidea, interordinal relationships within Placentalia, proboscidean taxonomy in general and South American in particular, anatomy and physiology and some ecological considerations. New taxa above the family level include sister taxa Mammutida and Elephantida, and Plesielephantiformes as a sister taxon to Elephantiformes. Neontological research is currently under way on the Hyoid Apparatus, lungs, brain, hearing, ecology and behavior. Topics for future research include: phylogenetic positions of anthracobunids, Moeritherium, tetralophodont gomphotheres, Stegolophodon and Stegodon, and intra-familial relationships among Loxodonta, Elephas and Mammuthus, and continuing studies on encephalization quotient. Certain anatomical features and functions (e.g., the Hyoid Apparatus that helps in food procurement, in production of infrasonic sounds, and in storing water to be used in time of stress) evolved about 25 million years ago, in time for diversification into new niches when grasses appeared in the landscape.
Jaeyoung Jung - One of the best experts on this subject based on the ideXlab platform.
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structural analysis of the tongue and Hyoid Apparatus in a woodpecker
Acta Biomaterialia, 2016Co-Authors: Jaeyoung Jung, Steven E Naleway, Nicholas A Yaraghi, Steven Herrera, Vincent R Sherman, Eric A Bushong, Mark H Ellisman, David Kisailus, Joanna MckittrickAbstract:Abstract Woodpeckers avoid brain injury while they peck at trees up to 20 Hz with speeds up to 7 m/s, undergoing decelerations up to 1200 g. Along with the head, beak and neck, the Hyoid Apparatus (tongue bone and associated soft tissues) is subjected to these high impact forces. The shape of the Hyoid Apparatus is unusual in woodpeckers and its structure and mechanical properties have not been reported in detail. High-resolution X-ray micro-computed tomography and scanning electron microscopy with energy dispersive X-ray spectroscopy were performed and correlated with nanoindentation mapping. The Hyoid Apparatus has four distinct bone sections, with three joints between these sections. Nanoindentation results on cross-sectional regions of each bone reveal a previously unreported structure consisting of a stiff core and outer, more compliant shell with moduli of up to 27.4 GPa and 8.5 GPa, respectively. The bending resistance is low at the posterior section of the Hyoid bones, indicating that this region has a high degree of flexibility to absorb impact. These new structural findings can be applied to further studies on the energy dissipation of the woodpecker during its drumming behavior, and may have implications for the design of engineered impact-absorbing structures. Statement of Significance Woodpeckers avoid brain injury while they peck at trees, which results in extreme impact conditions. One common adaptation in woodpeckers is the unusual shape of the elongated tongue, also called the Hyoid Apparatus. The relationship between the structure and mechanical properties of the bony part of the Hyoid Apparatus has not been previously reported. A three dimensional model of the bony tongue was developed, and the hardness and stiffness were evaluated. A new type of bone structure, which is opposite of typical skeletal bone structure was found. The combined microstructural and mechanical property analysis indicate possible energy absorption routes for the Hyoid Apparatus and are applicable to the design of engineered structures.