scholarly journals Digging the compromise: investigating the link between limb bone histology and fossoriality in the aardvark (Orycteropus afer)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5216 ◽  
Author(s):  
Lucas J. Legendre ◽  
Jennifer Botha-Brink
Keyword(s):  
General Pattern ◽  
Bone Microstructure ◽  
Bone Histology ◽  
Tissue Type ◽  
Subterranean Rodents ◽  
Functional Link ◽  
Limb Bone ◽  
Limb Bones ◽  
Physiological Constraints ◽  
Digging Behavior

Bone microstructure has long been known as a powerful tool to investigate lifestyle-related biomechanical constraints, and many studies have focused on identifying such constraints in the limb bones of aquatic or arboreal mammals in recent years. The limb bone microstructure of fossorial mammals, however, has not been extensively described. Furthermore, so far, studies on this subject have always focused on the bone histology of small burrowers, such as subterranean rodents or true moles. Physiological constraints associated with digging, however, are known to be strongly influenced by body size, and larger burrowers are likely to exhibit a histological profile more conspicuously influenced by fossorial activity. Here, we describe for the first time the limb bone histology of the aardvark (Orycteropus afer), the largest extant burrowing mammal. The general pattern is very similar for all six sampled limb bones (i.e., humerus, radius, ulna, femur, tibia, and fibula). Most of the cortex at midshaft is comprised of compacted coarse cancellous bone (CCCB), an endosteal tissue formed in the metaphyses through the compaction of bony trabeculae. Conversely, the periosteal bone is highly resorbed in all sections, and is reduced to a thin outer layer, suggesting a pattern of strong cortical drift. This pattern contrasts with that of most large mammals, in which cortical bone is of mostly periosteal origin, and CCCB, being a very compliant bone tissue type, is usually resorbed or remodeled during ontogeny. The link between histology and muscle attachment sites, as well as the influence of the semi-arid environment and ant-eating habits of the aardvark on its bone microstructure, are discussed. We hypothesize that the unusual histological profile of the aardvark is likely the outcome of physiological constraints due to both extensive digging behavior and strong metabolic restrictions. Adaptations to fossoriality are thus the result of a physiological compromise between limited food availability, an environment with high temperature variability, and the need for biomechanical resistance during digging. These results highlight the difficulties of deciphering all factors potentially involved in bone formation in fossorial mammals. Even though the formation and maintaining of CCCB through ontogeny in the aardvark cannot be unambiguously linked with its fossorial habits, a high amount of CCCB has been observed in the limb bones of other large burrowing mammals. The inclusion of such large burrowers in future histological studies is thus likely to improve our understanding of the functional link between bone growth and fossorial lifestyle in an evolutionary context.

scholarly journals Climatic influence on the growth pattern of Panthasaurus maleriensis from the Late Triassic of India deduced from paleohistology

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9868
Author(s):  
Elżbieta M. Teschner ◽  
Sanjukta Chakravorti ◽  
Dhurjati P. Sengupta ◽  
Dorota Konietzko-Meier
Keyword(s):  
Growth Pattern ◽  
Environmental Influence ◽  
Wide Spectrum ◽  
Climatic Conditions ◽  
Bone Histology ◽  
Late Triassic ◽  
Tissue Type ◽  
Thin Sections ◽  
Local Climate ◽  
Limb Bones

Metoposaurids are representatives of the extinct amphibian clade Temnospondyli, found on almost every continent exclusively in the Late Triassic deposits. Osteohistologically, it is one of the best-known temnospondyl groups, analyzed with a wide spectrum of methods, such as morphology, morphometry, bone histology or computed modelling. The least known member of Metoposauridae is Panthasaurus maleriensis from the Pranhita-Godavari basin in Central India, being geographically the most southern record of this family. For the first time the bone histology of this taxon was studied with a focus on the intraspecific variability of the histological framework and the relationship between the observed growth pattern and climatic and/or environmental conditions. The studied material includes thin-sections of five long bones, a rib, an ilium and an intercentrum belonging most likely to eight individuals ranging from different ontogenetic stages. All bones have a large medullary region with progressively increasing remodeling, surrounded by a lamellar-zonal tissue type. The primary cortex consists of parallel-fibered matrix showing various degrees of organization, less organized collagen fibers in the zones and higher organized in the annuli. Growth marks occur in the form of alternating zones and annuli in every bone except the ilium and the intercentrum. The vascularity becomes less dense towards the outermost cortex in all sampled limb bones. Towards the outermost cortex the zone thickness is decreasing, in contrast to the avascular annuli, that become thicker or are of the same thickness. The growth pattern of P. maleriensis is uniform and represents changes in ontogenetic development. Multiple resting lines are prominent in the outer annuli of the limb bones and the rib and they presumably indicate climatic and environmental influence on the growth pattern. Therefore, a prolonged phase of slowed-down growth occurred during the unfavorable phase, but a complete cessation of growth indicated by Lines of Arrested Growth (LAGs) is not recorded in the studied samples. Based on the histological framework we conclude that the climate had an impact on the growth pattern. As we do not see any LAGs in the Indian metoposaurid, we assume that the local climate was relatively mild in India during the Late Triassic. A similar prolonged phase of slowed down growth without the occurrence of LAGs was observed in Metoposaurus krasiejowensis from the Late Triassic of Krasiejów (Poland). This is in contrast to Moroccan metoposaurid Dutuitosaurus ouazzoui from the Late Triassic of Argana Basin, where LAGs are regularly deposited throughout ontogeny indicating most likely harsher climatic conditions.

scholarly journals Functional Morphology and Morphological Diversification of Hind Limb Cross-Sectional Traits in Mustelid Mammals

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
P Parsi-Pour ◽  
B M Kilbourne
Keyword(s):  
Hind Limb ◽  
Structural Strength ◽  
Aquatic Environments ◽  
Sectional Area ◽  
Cross Sectional ◽  
Phylogenetic Relatedness ◽  
Limb Bone ◽  
Limb Bones ◽  
Section Modulus ◽  
Second Moments

Synopsis Locomotor habits in mammals are strongly tied to limb bones’ lengths, diameters, and proportions. By comparison, fewer studies have examined how limb bone cross-sectional traits relate to locomotor habit. Here, we tested whether climbing, digging, and swimming locomotor habits reflect biomechanically meaningful differences in three cross-sectional traits rendered dimensionless— cross-sectional area (CSA), second moments of area (SMA), and section modulus (MOD)—using femora, tibiae, and fibulae of 28 species of mustelid. CSA and SMA represent resistance to axial compression and bending, respectively, whereas MOD represents structural strength. Given the need to counteract buoyancy in aquatic environments and soil’s high density, we predicted that natatorial and fossorial mustelids have higher values of cross-sectional traits. For all three traits, we found that natatorial mustelids have the highest values, followed by fossorial mustelids, with both of these groups significantly differing from scansorial mustelids. However, phylogenetic relatedness strongly influences diversity in cross-sectional morphology, as locomotor habit strongly correlates with phylogeny. Testing whether hind limb bone cross-sectional traits have evolved adaptively, we fit Ornstein–Uhlenbeck (OU) and Brownian motion (BM) models of trait diversification to cross-sectional traits. The cross-sectional traits of the femur, tibia, and fibula appear to have, respectively, diversified under a multi-rate BM model, a single rate BM model, and a multi-optima OU model. In light of recent studies on mustelid body size and elongation, our findings suggest that the mustelid body plan—and perhaps that of other mammals—is likely the sum of a suite of traits evolving under different models of trait diversification.

Appendix 4. The Hoxne mammalian remains

1956 ◽  
Vol 239 (665) ◽  
pp. 354-356 ◽  
Keyword(s):  
Pollen Analysis ◽  
Cervus Elaphus ◽  
Equus Caballus ◽  
Bone Surface ◽  
Limb Bone ◽  
Limb Bones

The mammalian remains from Hoxne are few in number and variety. Of the fossils which have been collected only a part have been preserved. Most of these are in the collections at Ipswich Museum and are from Moir’s (1926, 1935) excavations, and these are listed below. The stratigraphical horizon is given where known. Trogontherium sp. Femur and eight molars from stratum E. Provisionally determined by Dr T. M. Stout as T. lydekkeri Schlosser. Cervus elaphus L. Limb bones, antler fragments and a vertebra. These remains represent at least six animals. A radius and a metacarpal were found together in stratum F lying on the Lowestoft Till; these were the only finds during the recent investigations. Their position in the stratigraphy was verified by pollen analysis (no. 10, table 5) of sediment from the bone surface. Bos or Bison sp. Tooth and a limb bone. Equus caballus L. Teeth and limb bones. These belong to at least eight beasts. Several of the teeth are known to have come from stratum A 2. Elephas sp. Ilium.

scholarly journals Shell bone histology indicates terrestrial palaeoecology of basal turtles

2007 ◽  
Vol 274 (1620) ◽  
pp. 1885-1893 ◽  
Author(s):  
Torsten M Scheyer ◽  
P.Martin Sander
Keyword(s):  
Fossil Record ◽  
Compact Bone ◽  
Upper Triassic ◽  
Bone Histology ◽  
The Other ◽  
Late Triassic ◽  
Aquatic Habitats ◽  
Terrestrial Habitat ◽  
Limb Bone ◽  
Terrestrial Habitats

The palaeoecology of basal turtles from the Late Triassic was classically viewed as being semi-aquatic, similar to the lifestyle of modern snapping turtles. Lately, this view was questioned based on limb bone proportions, and a terrestrial palaeoecology was suggested for the turtle stem. Here, we present independent shell bone microstructural evidence for a terrestrial habitat of the oldest and basal most well-known turtles, i.e. the Upper Triassic Proterochersis robusta and Proganochelys quenstedti . Comparison of their shell bone histology with that of extant turtles preferring either aquatic habitats or terrestrial habitats clearly reveals congruence with terrestrial turtle taxa. Similarities in the shell bones of these turtles are a diploe structure with well-developed external and internal cortices, weak vascularization of the compact bone layers and a dense nature of the interior cancellous bone with overall short trabeculae. On the other hand, ‘aquatic’ turtles tend to reduce cortical bone layers, while increasing overall vascularization of the bone tissue. In contrast to the study of limb bone proportions, the present study is independent from the uncommon preservation of appendicular skeletal elements in fossil turtles, enabling the palaeoecological study of a much broader range of incompletely known turtle taxa in the fossil record.

scholarly journals Limb bone loading in swimming turtles: changes in loading facilitate transitions from tubular to flipper-shaped limbs during aquatic invasions

2015 ◽  
Vol 11 (6) ◽  
pp. 20150110 ◽  
Author(s):  
Vanessa K Hilliard Young ◽  
Richard W. Blob
Keyword(s):  
Cross Sections ◽  
Morphological Changes ◽  
Skeletal Morphology ◽  
Limb Bone ◽  
Limb Bones ◽  
Terrestrial Vertebrate ◽  
Aquatic Invasions ◽  
Torsional Loads ◽  
The Impact

Members of several terrestrial vertebrate lineages have returned to nearly exclusive use of aquatic habitats. These transitions were often accompanied by changes in skeletal morphology, such as flattening of limb bone shafts. Such morphological changes might be correlated with the exposure of limb bones to altered loading. Though the environmental forces acting on the skeleton differ substantially between water and land, no empirical data exist to quantify the impact of such differences on the skeleton, either in terms of load magnitude or regime. To test how locomotor loads change between water and land, we compared in vivo strains from femora of turtles ( Trachemys scripta ) during swimming and terrestrial walking. As expected, strain magnitudes were much lower (by 67.9%) during swimming than during walking. However, the loading regime of the femur also changed between environments: torsional strains are high during walking, but torsion is largely eliminated during swimming. Changes in loading regime between environments may have enabled evolutionary shifts to hydrodynamically advantageous flattened limb bones in highly aquatic species. Although circular cross sections are optimal for resisting torsional loads, the removal of torsion would reduce the advantage of tubular shapes, facilitating the evolution of flattened limbs.

scholarly journals Limb bone histology and growth inPlacerias hesternus(Therapsida: Anomodontia) from the Upper Triassic of North America

Palaeontology ◽  
2010 ◽  
Vol 53 (2) ◽  
pp. 347-364 ◽  
Author(s):  
JEREMY L. GREEN ◽  
MARY H. SCHWEITZER ◽  
ELLEN-THERESE LAMM
Keyword(s):  
North America ◽  
Upper Triassic ◽  
Bone Histology ◽  
Limb Bone

Intrasite Spatial Analysis of Bone: Subtracting the Effect of Secondary Carnivore Consumers

1994 ◽  
Vol 59 (4) ◽  
pp. 748-768 ◽  
Author(s):  
Curtis W. Marean ◽  
Leanne Bertino
Keyword(s):  
Spatial Analysis ◽  
Human Behavior ◽  
Experimental Studies ◽  
Archaeological Site ◽  
Original Position ◽  
Limb Bone ◽  
Limb Bones ◽  
Animal Bones ◽  
Spotted Hyenas ◽  
Bone Fragments

Animal bones discarded by people are commonly subject to disturbance by carnivores. These carnivores are present throughout the world and include wolves, coyotes, hyenas, and many others. This disturbance not only modifies and destroys bone, but also moves many of the bone fragments away from their original position of discard. Intrasite spatial analyses of bone that seek patterns meaningful to human behavior thus need to subtract the effect of carnivore disturbance. Experimental studies with spotted hyenas show that the position of a bone fragment on a limb bone, combined with bone surface modification, can be used to identify a class of bone fragments that are minimally affected by carnivores and are thus the best indicators of spatial patterning resulting from human behavior. Limb-bone ends are moved significant distances, as are shaft fragments as a general class. However, middle-shaft portions of limb bones that preserve percussion marks from hammerstone breakage retain nearly the precise spatial position as originally discarded by hominids. Thus, any spatial analysis of bone, when carnivores are implicated as contributors or consumers at an archaeological site, should focus on middle-shaft portions of limb bones with percussion marks.

scholarly journals Mechanics of limb bone loading during terrestrial locomotion in the green iguana (Iguana iguana) and American alligator (Alligator mississippiensis)

2001 ◽  
Vol 204 (6) ◽  
pp. 1099-1122 ◽  
Author(s):  
R.W. Blob ◽  
A.A. Biewener
Keyword(s):  
Reaction Force ◽  
Alligator Mississippiensis ◽  
Upright Posture ◽  
Safety Factors ◽  
Iguana Iguana ◽  
Limb Bone ◽  
Limb Bones ◽  
Bone Stress ◽  
Bone Loading

In vivo measurements of strain in the femur and tibia of Iguana iguana (Linnaeus) and Alligator mississippiensis (Daudin) have indicated three ways in which limb bone loading in these species differs from patterns observed in most birds and mammals: (i) the limb bones of I. iguana and A. mississippiensis experience substantial torsion, (ii) the limb bones of I. iguana and A. mississippiensis have higher safety factors than those of birds or mammals, and (iii) load magnitudes in the limb bones of A. mississippiensis do not decrease uniformly with the use of a more upright posture. To verify these patterns, and to evaluate the ground and muscle forces that produce them, we collected three-dimensional kinematic and ground reaction force data from subadult I. iguana and A. mississippiensis using a force platform and high-speed video. The results of these force/kinematic studies generally confirm the loading regimes inferred from in vivo strain measurements. The ground reaction force applies a torsional moment to the femur and tibia in both species; for the femur, this moment augments the moment applied by the caudofemoralis muscle, suggesting large torsional stresses. In most cases, safety factors in bending calculated from force/video data are lower than those determined from strain data, but are as high or higher than the safety factors of bird and mammal limb bones in bending. Finally, correlations between limb posture and calculated stress magnitudes in the femur of I. iguana confirm patterns observed during direct bone strain recordings from A. mississippiensis: in more upright steps, tensile stresses on the anterior cortex decrease, but peak compressive stresses on the dorsal cortex increase. Equilibrium analyses indicate that bone stress increases as posture becomes more upright in saurians because the ankle and knee extensor muscles exert greater forces during upright locomotion. If this pattern of increased bone stress with the use of a more upright posture is typical of taxa using non-parasagittal kinematics, then similar increases in load magnitudes were probably experienced by lineages that underwent evolutionary shifts to a non-sprawling posture. High limb bone safety factors and small body size in these lineages could have helped to accommodate such increases in limb bone stress.

scholarly journals New light shed on the early evolution of limb-bone growth plate and bone marrow

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jordi Estefa ◽  
Paul Tafforeau ◽  
Alice M Clement ◽  
Jozef Klembara ◽  
Grzegorz Niedźwiedzki ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Blood Cells ◽  
Bone Growth ◽  
Bone Development ◽  
Three Dimensional ◽  
Early Evolution ◽  
Long Bone ◽  
Long Bones ◽  
Limb Bone ◽  
Limb Bones

The production of blood cells (haematopoiesis) occurs in the limb bones of most tetrapods but is absent in the fin bones of ray-finned fish. When did long bones start producing blood cells? Recent hypotheses suggested that haematopoiesis migrated into long bones prior to the water-to-land transition and protected newly-produced blood cells from harsher environmental conditions. However, little fossil evidence to support these hypotheses has been provided so far. Observations of the humeral microarchitecture of stem-tetrapods, batrachians, and amniotes were performed using classical sectioning and three-dimensional synchrotron virtual histology. They show that Permian tetrapods seem to be among the first to exhibit a centralised marrow organisation, which allows haematopoiesis as in extant amniotes. Not only does our study demonstrate that long-bone haematopoiesis was probably not an exaptation to the water-to-land transition but it sheds light on the early evolution of limb-bone development and the sequence of bone-marrow functional acquisitions.

scholarly journals БИЛАТЕРАЛЬНАЯ АСИММЕТРИЯ ДЛИННЫХ КОСТЕЙ СКЕЛЕТА У ТОБОЛО-ИРТЫШСКИХ ТАТАР

2021 ◽  
pp. 292-310
Author(s):  
Алена Владимировна Дедик
Keyword(s):  
Sex Differences ◽  
Upper Limb ◽  
Lower Limb ◽  
Skeletal System ◽  
Bilateral Asymmetry ◽  
Male And Female ◽  
Limb Bone ◽  
Limb Bones ◽  
The Asymmetry

В статье представлены результаты изучения билатеральной асимметрии длинных костей скелета у четырёх групп тоболо-иртышских татар: аялынских, тобольских, тюменских и коурдакско-саргатских татар. Для каждой группы мужчин и женщин была рассчитаны коэффициенты асимметрии (использовалась формула R–L), процентное соотношение которых показывает, что наиболее симметричная скелетная система у аялынских татар, а самая асимметричная у коурдакско-саргатских татар. При анализе коэффициентов асимметрии отдельных костей, было выявлено, что во всех исследуемых группах у мужчин и женщин самой асимметричной костью является плечевая кость. Анализ коэффициентов асимметрии по отдельным признакам показал, что во всех группах наибольшей асимметрией отличаются продольные диаметры костей верхних конечностей. Левосторонняя асимметрия в группах тоболо-иртышских татар в основном характерна для признаков костей нижних конечностей как у мужчин, так и у женщин. Закономерности в половом распределении коэффициентов асимметрии в группах тоболо-иртышских татар выявлены не были. Для наглядности изменчивости коэффициентов асимметрии для мужских и женских групп тоболо-иртышских татар были построены комбинационные полигоны, форма которых показала, что наиболее схожи между собой мужчины тобольских и коурдакско-саргатских татар, а аялынские и тюменские татары заметно отличаются как от этих групп, так и между собой. Формы комбинационных полигонов женских серий тоболо-иртышских татар не обнаруживают видимого сходства между собой. Таким образом, выявленные различия в асимметрии скелетной системы этно-территориальных групп тоболо-иртышских татар, возможно, связаны с хозяйственным укладом жизни татар, который, ввиду различной территории расселения тех или иных этно-территориальных групп, заметно отличался. The article presents the results of studying the limb bone bilateral asymmetry in four groups of the Tobol-Irtysh Tatars: Ayalyn, Tobolsk, Tyumen and Kourdak-Sargat Tatars. The asymmetry coefficients were calculated for the male and female samples of each group (using the R – L formula). The Ayalyn Tatars resulted to have the most symmetric skeletal system, while the Kourdak-Sargat Tatars – the least symmetrical one. The analysis of the asymmetry coefficients of individual bones revealed that the humerus is the most asymmetric bone in both sexes among all the studied groups. The lengths of the upper limb bones resulted to be the most asymmetrical measurement in all groups. Left-sided asymmetry was mainly seen in the lower limb bones among the Tobol-Irtysh Tatars. No sex differences in the asymmetry coefficients were revealed. Combination polygons were produced to illustrate the variability of the asymmetry coefficients for the male and female samples. Male samples of the Tobolsk and Kourdak-Sargat Tatars were found to be most similar to each other, and the Ayalyn and Tyumen Tatars are noticeably different both from these groups and from each other. The combination polygons of the female samples of the Tobol-Irtysh Tatars do not reveal any visible similarity between them. Thus, the revealed differences in the asymmetry of the skeletal system of the Tobol-Irtysh Tatars ethno-territorial groups are possibly associated with different economy systems of the groups.

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