scholarly journals Bone histology of varanopids (Synapsida) from Richards Spur, Oklahoma, sheds light on growth patterns and lifestyle in early terrestrial colonizers

2020 ◽  
Vol 375 (1793) ◽  
pp. 20190142 ◽  
Author(s):  
Adam K. Huttenlocker ◽  
Christen D. Shelton
Keyword(s):  
Postnatal Growth ◽  
Growth Patterns ◽  
Bone Histology ◽  
Skeletal Growth ◽  
Long Bone ◽  
Lower Permian ◽  
Femoral Bone ◽  
Theme Issue ◽  
Body Sizes ◽  
Fissure Fill

Varanopids were a group of small to medium-sized synapsids whose fossil record spans the Carboniferous through middle Permian. Although their phylogenetic relationships have received some interest in recent years, little is known about other aspects of their palaeobiology, including their skeletal growth, allometry and habitat preference. Here, we describe varanopid long bone histology based on a sample of well-preserved femora from the lower Permian Richards Spur fissure fill locality, Comanche County, Oklahoma, USA. The sample includes five femora from at least two varanopid taxa— Mycterosaurus and the large varanodontine Varanops brevirostris —and four additional mycterosaurine femora not diagnosed to genus. Prior work on femoral bone compactness provided a baseline to make lifestyle inferences and evaluate whether varanopids were ancestrally terrestrial. Moreover, the large availability of specimens spanning different sizes made possible an assessment of size-related ontogenetic histovariability. All specimens revealed moderately dense cortical bone tissues composed of sparsely vascularized parallel-fibred and lamellar bone with radially arranged rows of longitudinal canals (mostly simple), and many preserved regularly spaced growth marks (annuli and lines of arrested growth) as in modern varanids. We show that bone histology has the potential to explain how ballast was shed and the skeleton lightened for terrestrial mobility in ancestral synapsids and their basal amniote kin, as well as how adjustments in postnatal growth influenced the evolution of larger body sizes in the terrestrial frontier. This article is part of the theme issue ‘Vertebrate palaeophysiology'.

scholarly journals Ophiacodon long bone histology: the earliest occurrence of FLB in the mammalian stem lineage

2015 ◽  
Author(s):  
Christen Shelton ◽  
P. Martin Sander
Keyword(s):  
Bone Matrix ◽  
Bone Histology ◽  
Skeletal Growth ◽  
Long Bone ◽  
Early Permian ◽  
Additional Material ◽  
Evolutionary Origins ◽  
Woven Bone ◽  
Stem Lineage ◽  
Histological Characteristics

The origin of mammalian endothermy has long been held to reside within the early therapsid groups. However, shared histological characteristics have been observed in the bone matrix and vascularity between Ophiacodontidae and the later therapsids (Synapsida). Historically, this coincidence has been explained as simply a reflection of the presumed aquatic lifestyle of Ophiacodon or even a sign of immaturity. Here we show, by histologically sampling an ontogenetic series of Ophiacodon humeri, as well as additional material, the existence of true fibrolamellar bone in the postcranial bones of a member of ‘Pelycosauria’. Our findings have reaffirmed what previous studies first described as fast growing tissue, and by proxy, have disproven that the highly vascularized cortex is simply a reflection of young age. This tissue demonstrates the classic histological characteristics of true fibrolamellar bone (FLB). The cortex consists of primary osteons in a woven bone matrix and remains highly vascularized throughout ontogeny providing evidence to fast skeletal growth. Overall, the FLB tissue we have described in Ophiacodon is more derived or “mammal-like” in terms of the osteonal development, bone matrix, and skeletal growth then what has been described thus far for any other pelycosaur taxa. Ophioacodon bone histology does not show well-developed Haversian tissue. With regards to the histological record, our results remain inconclusive as to the preferred ecology of Ophiacodon, but support the growing evidence for an aquatic lifestyle. Our findings have set the evolutionary origins of modern mammalian endothermy and high skeletal growth rates back approximately 20 M.Y. to the Early Permian, and by phylogenetic extension perhaps the Late Carboniferous.

scholarly journals Long Bone Histology and Growth Patterns in Ankylosaurs: Implications for Life History and Evolution

PLoS ONE ◽  
2013 ◽  
Vol 8 (7) ◽  
pp. e68590 ◽  
Author(s):  
Martina Stein ◽  
Shoji Hayashi ◽  
P. Martin Sander
Keyword(s):  
Life History ◽  
Growth Patterns ◽  
Bone Histology ◽  
Long Bone

scholarly journals Ophiacodon long bone histology: the earliest occurrence of FLB in the mammalian stem lineage

2015 ◽  
Author(s):  
Christen Shelton ◽  
P. Martin Sander
Keyword(s):  
Bone Matrix ◽  
Bone Histology ◽  
Skeletal Growth ◽  
Long Bone ◽  
Early Permian ◽  
Additional Material ◽  
Evolutionary Origins ◽  
Woven Bone ◽  
Stem Lineage ◽  
Histological Characteristics

The origin of mammalian endothermy has long been held to reside within the early therapsid groups. However, shared histological characteristics have been observed in the bone matrix and vascularity between Ophiacodontidae and the later therapsids (Synapsida). Historically, this coincidence has been explained as simply a reflection of the presumed aquatic lifestyle of Ophiacodon or even a sign of immaturity. Here we show, by histologically sampling an ontogenetic series of Ophiacodon humeri, as well as additional material, the existence of true fibrolamellar bone in the postcranial bones of a member of ‘Pelycosauria’. Our findings have reaffirmed what previous studies first described as fast growing tissue, and by proxy, have disproven that the highly vascularized cortex is simply a reflection of young age. This tissue demonstrates the classic histological characteristics of true fibrolamellar bone (FLB). The cortex consists of primary osteons in a woven bone matrix and remains highly vascularized throughout ontogeny providing evidence to fast skeletal growth. Overall, the FLB tissue we have described in Ophiacodon is more derived or “mammal-like” in terms of the osteonal development, bone matrix, and skeletal growth then what has been described thus far for any other pelycosaur taxa. Ophioacodon bone histology does not show well-developed Haversian tissue. With regards to the histological record, our results remain inconclusive as to the preferred ecology of Ophiacodon, but support the growing evidence for an aquatic lifestyle. Our findings have set the evolutionary origins of modern mammalian endothermy and high skeletal growth rates back approximately 20 M.Y. to the Early Permian, and by phylogenetic extension perhaps the Late Carboniferous.

scholarly journals Growth Interruptions in Arctic Rhodoliths Correspond to Water Depth and Rhodolith Morphology

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 538
Author(s):  
Moritz Schlüter ◽  
Ines Pyko ◽  
Max Wisshak ◽  
Christian Schulbert ◽  
Sebastian Teichert
Keyword(s):  
Light Availability ◽  
Growth Patterns ◽  
Skeletal Growth ◽  
Coralline Algae ◽  
Ambient Light ◽  
Micro Computed Tomography ◽  
Svalbard Archipelago ◽  
X Ray ◽  
Algal Thalli ◽  
Environmental Proxies

Coralline algae that form rhodoliths are widespread globally and their skeletal growth patterns have been used as (paleo-) environmental proxies in a variety of studies. However, growth interruptions (hiati) within their calcareous skeletons are regarded as problematic in this context. Here we investigated how hiati in the growth of Arctic rhodoliths from the Svalbard archipelago correspond to their environment and morphology. Using X-ray micro-computed tomography and stepwise model selections, we found that rhodoliths from deeper waters are subject to more frequent hiatus formation. In addition, rhodoliths with a higher sphericity (i.e., roundness) are less often affected by such growth interruptions. We conclude that these correlations are mainly regulated by hydrodynamics, because, in deeper waters, rhodoliths are not turned frequently enough to prevent a dieback of coralline algal thalli forming on the underside of the rhodolith. In this coherence, spheroidal rhodoliths are turned more easily, therefore shortening the amount of time between turnover events. Moreover, the incidence of light is more advantageous in shallower waters where rhodoliths exhibit a greater share of their surface to diffused ambient light, thus enabling thallus growth also on the down-facing surface of the rhodoliths. In consequence, information on the frequency of hiatus formation combined with rhodolith morphology might serve as a valuable proxy for (paleo-)environmental reconstructions in respect to light availability and the hydrodynamic regime.

Long-bone development and life-history traits of the Devonian tristichopterid Hyneria lindae

2018 ◽  
Vol 109 (1-2) ◽  
pp. 75-86 ◽  
Author(s):  
Viktoriia KAMSKA ◽  
Edward B. DAESCHLER ◽  
Jason P. DOWNS ◽  
Per E. AHLBERG ◽  
Paul TAFFOREAU ◽  
...  
Keyword(s):  
Life History ◽  
Limb Development ◽  
Life History Traits ◽  
Bone Development ◽  
Bone Histology ◽  
Long Bone ◽  
General Character ◽  
Appendicular Skeleton ◽  
Predatory Behaviour ◽  
Large Size

ABSTRACTHyneria lindae is one of the largest Devonian sarcopterygians. It was found in the Catskill Formation (late Famennian) of Pennsylvania, USA. The current study focuses on the palaeohistology of the humerus of this tristichopterid and supports a low ossification rate and a late ossification onset in the appendicular skeleton. In addition to anatomical features, the large size of the cell lacunae in the cortical bone of the humerus mid-shaft may suggest a large genome size and associated neotenic condition for this species, which could, in turn, be a partial explanation for the large size of H. lindae. The low metabolism of H. lindae revealed here by bone histology supports the hypothesis of an ambush predatory behaviour. Finally, the lines-of-arrested-growth pattern and late ossification of specimen ANSP 21483 suggest that H. lindae probably had a long juvenile stage before reaching sexual maturity. Although very few studies address the life-history traits of stem tetrapods, they all propose a slow limb development for the studied taxa despite different ecological conditions and presumably distinct behaviours. The bone histology of H. lindae would favour the hypothesis that a slow long-bone development could be a general character for stem tetrapods.

scholarly journals Case study of radial fibrolamellar bone tissues in the outer cortex of basal sauropods

2020 ◽  
Vol 375 (1793) ◽  
pp. 20190143 ◽  
Author(s):  
Benjamin Jentgen-Ceschino ◽  
Koen Stein ◽  
Valentin Fischer
Keyword(s):  
Bone Tissue ◽  
Periosteal Reaction ◽  
Bone Histology ◽  
Long Bones ◽  
Pathological Feature ◽  
Bone Surface ◽  
Theme Issue ◽  
Outer Cortex ◽  
Aggressive Form

The histology of sauropod long bones often appears uniform and conservative along their evolutionary tree. One of the main aspects of their bone histology is to exhibit a fibrolamellar complex in the cortex of their long bones. Here, we report another bone tissue, the radial fibrolamellar bone (RFB), in the outer cortex of the humeri of a young adult cf. Isanosaurus (Early to Late Jurassic, Thailand) and an adult Spinophorosaurus nigerensis (Early to Middle Jurassic, Niger) that do not exhibit any pathological feature on the bone surface. Its location within the cortex is unexpected, because RFB is a rapidly deposited bone tissue that would rather be expected early in the ontogeny. A palaeopathological survey was conducted for these sampled specimens. Observed RFB occurrences are regarded as spiculated periosteal reactive bone, which is an aggressive form of periosteal reaction. A ‘hair-on-end’ pattern of neoplasmic origin (resembling a Ewing's sarcoma) is favoured for cf. Isanosaurus , while a sunburst pattern of viral or neoplasmic origin (resembling an avian osteopetrosis or haemangioma) is favoured for Spinophorosaurus . This study highlights the importance of bone histology in assessing the frequency and nature of palaeopathologies. This article is part of the theme issue ‘Vertebrate palaeophysiology’.

The growth pattern of the African tortoise Geochelone pardalis and other chelonians

1999 ◽  
Vol 77 (2) ◽  
pp. 181-193 ◽  
Author(s):  
Adrian Hailey ◽  
Ian M Coulson
Keyword(s):  
Growth Pattern ◽  
High Growth ◽  
Growth Patterns ◽  
Growth Rings ◽  
Frequency Distributions ◽  
The North ◽  
Body Sizes ◽  
Biased Sex Ratio ◽  
The Difference ◽  
North And South

Growth rings were measured in dead African leopard tortoises, Geochelone pardalis, collected in the seasonal tropics of Zimbabwe over an 11-year period. A series of Ford-Walford plots using growth measured from annuli showed that growth fitted a logistic by mass curve best, logistic by length and Gompertz curves less well, and a Bertalanffy curve least well. The Bertalanffy curve, often fitted to growth of chelonians, is characterised by particularly high growth rates of juveniles compared with larger individuals. It is suggested that this growth pattern is likely to be found in species showing a marked decrease in diet quality with size. This hypothesis is supported by a review of growth patterns in chelonians: Bertalanffy curves are associated with an omnivorous (and thus potentially variable) diet and other growth patterns with an obligate carnivorous or herbivorous diet. Geochelone pardalis in Zimbabwe showed significant sexual size dimorphism, the mean asymptotic mass of females being 1.7 times that of males, unlike populations with larger body sizes to the north and south. Annual survival estimated from age-frequency distributions was significantly higher in males (0.80) than in females (0.72), the difference being sufficient to account for the male-biased sex ratio of live animals.

Ontogenetic changes in long-bone histology of an ornithomimid theropod dinosaur from the Upper Cretaceous Bissekty Formation of Uzbekistan

2016 ◽  
Vol 29 (6) ◽  
pp. 715-729 ◽  
Author(s):  
Pavel P. Skutschas ◽  
Elizaveta A. Boitsova ◽  
Alexander O. Averianov ◽  
Hans-Dieter Sues
Keyword(s):  
Upper Cretaceous ◽  
Bone Histology ◽  
Long Bone ◽  
Ontogenetic Changes ◽  
Theropod Dinosaur
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