scholarly journals Developmental growth patterns of the filter-feeder pterosaur, Pterodaustro guiñazui

2008 ◽  
Vol 4 (3) ◽  
pp. 282-285 ◽  
Author(s):  
A Chinsamy ◽  
L Codorniú ◽  
L Chiappe
Keyword(s):  
Growth Dynamics ◽  
Growth Patterns ◽  
Growth Strategy ◽  
Filter Feeder ◽  
Definitive Evidence ◽  
Developmental Growth ◽  
Adult Body ◽  
Body Sizes ◽  
Determinate Growth ◽  
Insight Into

Life-history parameters of pterosaurs such as growth and ontogenetic development represent an enigma. This aspect of pterosaur biology has remained perplexing because few pterosaur taxa are represented by complete ontogenetic series. Of these, Pterodaustro is unique in that besides being represented by hundreds of individuals with wing spans ranging from 0.3 to 2.5 m, it includes an embryo within an egg. Here we present a comprehensive osteohistological assessment of multiple skeletal elements of a range of ontogenetic sizes of Pterodaustro , and we provide unparalleled insight into its growth dynamics. We show that, upon hatching, Pterodaustro juveniles grew rapidly for approximately 2 years until they reached approximately 53% of their mature body size, whereupon they attained sexual maturity. Thereafter, growth continued for at least another 3–4 years at comparatively slower rates until larger adult body sizes were attained. Our analysis further provides definitive evidence that Pterodaustro had a determinate growth strategy.

scholarly journals Aquatic insects are dramatically underrepresented in genomic research

2020 ◽  
Author(s):  
Scott Hotaling ◽  
Joanna L. Kelley ◽  
Paul B. Frandsen
Keyword(s):  
Aquatic Insects ◽  
Small Body ◽  
Aquatic Insect ◽  
Freshwater Ecosystems ◽  
Future Research ◽  
Insect Genome ◽  
Terrestrial Insect ◽  
Body Sizes ◽  
Terrestrial Insects ◽  
Insight Into

AbstractAquatic insects comprise 10% of all insect diversity, can be found on every continent except Antarctica, and are key components of freshwater ecosystems. Yet aquatic insect genome biology lags dramatically behind that of terrestrial insects. If genomic effort was spread evenly, one aquatic insect genome would be sequenced for every ∼9 terrestrial insect genomes. Instead, ∼24 terrestrial insect genomes have been sequenced for every aquatic insect genome. This discrepancy is even more dramatic if the quality of genomic resources is considered; for instance, while no aquatic insect genome has been assembled to the chromosome level, 29 terrestrial insect genomes spanning four orders have. We argue that a lack of aquatic insect genomes is not due to any underlying difficulty (e.g., small body sizes or unusually large genomes) yet it is severely hampering aquatic insect research at both fundamental and applied scales. By expanding the availability of aquatic insect genomes, we will gain key insight into insect diversification and empower future research for a globally important taxonomic group.Simple SummaryAquatic insects comprise 10% of all insect diversity, can be found on every continent except Antarctica, and are key components of freshwater ecosystems. Yet aquatic insect genome biology lags dramatically behind that of terrestrial insects. If genomic effort was spread evenly, one aquatic insect genome would be sequenced for every ∼9 terrestrial insect genomes. Instead, ∼24 terrestrial insect genomes have been sequenced for every aquatic insect genome. We argue that the limited availability of aquatic insect genomes is not due to practical limitations—e.g., small body sizes or overly complex genomes—but instead reflects a lack of research interest. We call for targeted efforts to expand the availability of aquatic insect genomic resources to gain key molecular insight into insect diversification and empower future research.

Geographical and latitudinal variation in growth patterns and adult body size of Swedish moose (Alces alces)

Oecologia ◽  
1995 ◽  
Vol 102 (4) ◽  
pp. 433-442 ◽  
Author(s):  
H�kan Sand ◽  
G�ran Cederlund ◽  
Kjell Danell
Keyword(s):  
Body Size ◽  
Alces Alces ◽  
Growth Patterns ◽  
Latitudinal Variation ◽  
Adult Body Size ◽  
Adult Body

Insight into light-driven antibacterial cotton fabrics decorated by in situ growth strategy

2020 ◽  
Vol 579 ◽  
pp. 233-242 ◽  
Author(s):  
Xiaolin Nie ◽  
Shuanglin Wu ◽  
Alfred Mensah ◽  
Qingqing Wang ◽  
Fenglin Huang ◽  
...  
Keyword(s):  
Cotton Fabrics ◽  
Growth Strategy ◽  
In Situ Growth ◽  
Insight Into

scholarly journals Caenagnathids of the Dinosaur Park Formation (Campanian) of Alberta, Canada: anatomy, osteohistology, taxonomy, and evolution

2020 ◽  
Vol 8 ◽  
pp. 105-153 ◽  
Author(s):  
Gregory Funston
Keyword(s):  
Body Size ◽  
Skeletal Maturity ◽  
Niche Overlap ◽  
Niche Space ◽  
The Past ◽  
Adult Body ◽  
New Material ◽  
Taxonomic Framework ◽  
Dinosaur Park Formation ◽  
Insight Into

Our understanding of caenagnathid anatomy, diversity, and ecology has improved considerably in the past twenty years, but numerous issues still remain. Among these, the diversity and taxonomy of caenagnathids from the Dinosaur Park Formation of Alberta, Canada, have remained problematic. Whereas some authors recognize three genera, others suggest only two were present, and there is considerable disagreement about which specimens are referable to which genus. This study aims to resolve this issue by reviewing the known specimens and using osteohistology, to establish a testable taxonomic framework of Dinosaur Park Formation caenagnathids. Numerous new specimens from all regions of the skeleton provide insight into morphological variation in caenagnathids, and three morphotypes are recognized based on a combination of morphological features and body size. Osteohistology shows that representatives in each body size class are at skeletal maturity, and therefore supports the delineation of three taxa: the smaller Citipes elegans gen. nov., the intermediate Chirostenotes pergracilis, and the larger Caenagnathus collinsi, new material of which shows it rivalled Anzu wyliei in size. However, these analyses also raise concerns about the referral of isolated material to each taxon in the absence of skeletal overlap between specimens or osteohistological analysis. Caenagnathids are consistently recovered throughout the Dinosaur Park Formation interval, and two geographic clusters of increased abundance probably reflect collection and taphonomic biases. The coexistence of three taxa was apparently facilitated by differences in both adult body size and functional morphology of the dentary and pes, which suggests that caenagnathids minimized niche overlap rather than subdividing niche space. Regardless, little is known of the exact roles caenagnathids played in Late Cretaceous ecosystems. Incorporation of the new material and taxonomic framework into a phylogenetic analysis drastically improves our understanding of the relationships between caenagnathines, and sheds light on the evolution of body size in caenagnathids and its role in their diversification.

scholarly journals Growth and Maturation in Development: A Fly’s Perspective

2020 ◽  
Vol 21 (4) ◽  
pp. 1260 ◽  
Author(s):  
Renald Delanoue ◽  
Nuria M. Romero
Keyword(s):  
Adult Stage ◽  
Body Height ◽  
Growth Hormones ◽  
Central Processor ◽  
Juvenile Period ◽  
Regulatory Pathways ◽  
Developmental Growth ◽  
Adult Body ◽  
Adult Fitness

In mammals like humans, adult fitness is improved due to resource allocation, investing energy in the developmental growth process during the juvenile period, and in reproduction at the adult stage. Therefore, the attainment of their target body height/size co-occurs with the acquisition of maturation, implying a need for coordination between mechanisms that regulate organismal growth and maturation timing. Insects like Drosophila melanogaster also define their adult body size by the end of the juvenile larval period. Recent studies in the fly have shown evolutionary conservation of the regulatory pathways controlling growth and maturation, suggesting the existence of common coordinator mechanisms between them. In this review, we will present an overview of the significant advancements in the coordination mechanisms ensuring developmental robustness in Drosophila. We will include (i) the characterization of feedback mechanisms between maturation and growth hormones, (ii) the recognition of a relaxin-like peptide Dilp8 as a central processor coordinating juvenile regeneration and time of maturation, and (iii) the identification of a novel coordinator mechanism involving the AstA/KISS system.

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.

Distinctive diel growth cycles in leaves and cladodes of CAM plants: differences from C3 plants and putative interactions with substrate availability, turgor and cytoplasmic pH

2005 ◽  
Vol 32 (5) ◽  
pp. 421 ◽  
Author(s):  
Liezel M. Gouws ◽  
C. Barry Osmond ◽  
Ulrich Schurr ◽  
Achim Walter
Keyword(s):  
Malic Acid ◽  
Growth Dynamics ◽  
Maximum Growth ◽  
Co2 Assimilation ◽  
Growth Patterns ◽  
Phase Iii ◽  
C3 Plants ◽  
Cytoplasmic Ph ◽  
Cam Plants ◽  
Cell Turgor

Distinct diel rhythms of leaf and cladode expansion growth were obtained in crassulacean acid metabolism (CAM) plants under water-limited conditions, with maxima at mid-day during phase III of CO2 assimilation. This pattern coincided with the availability of CO2 for photosynthesis and growth during the decarboxylation of malic acid, with maximum cell turgor due to the nocturnally accumulated malic acid, and with the period of low cytoplasmic pH associated with malic acid movement from vacuole to cytosol. Maximum growth rates were generally only 20% of those in C3 plants and were reached at a different time of the day compared with C3 plants. The results suggest that malic acid, as a source of carbohydrates, and a determinant of turgor and cytoplasmic pH, plays a major role in the control of diel growth dynamics in CAM plants under desert conditions. The observed plasticity in phasing of growth rhythms under situations of differing water availability suggests that a complex network of factors controls the diel growth patterns in CAM plants and needs to be investigated further.

scholarly journals Systematics and biogeography of Sternarchellini (Gymnotiformes: Apteronotidae): Diversification of electric fishes in large Amazonian rivers

2014 ◽  
Vol 12 (3) ◽  
pp. 565-584 ◽  
Author(s):  
Stephen J. Ivanyisky III ◽  
James S. Albert
Keyword(s):  
Adaptive Evolution ◽  
Large Scale ◽  
Electric Fish ◽  
Morphological Characters ◽  
Species Assemblages ◽  
River Channels ◽  
Capture Event ◽  
Adult Body ◽  
Body Sizes ◽  
Biogeographic Analysis

The Sternarchellini (Gymnotiformes, Apteronotidae) is a clade of 10 electric fish species that inhabit deep river channels of the Amazon and Orinoco basins, attain moderate adult body sizes (15-50 cm TL), and have a predatory life style. Here we trace the evolutionary origin and diversification of Sternarchellini using standard phylogenetic and biogeographic procedures and a dataset of 70 morphological characters. The main results are: 1) the genus Sternarchellaincludes both species currently assigned to the genus Magosternarchus; and 2) neither of the multi-species assemblages of Sternarchellini in the Amazon and Orinoco basins are monophyletic. Historical biogeographic analysis suggests that sternarchelline evolution was linked to the large-scale river capture event that formed the modern Amazon and Orinoco basins, i.e. the Late Miocene rise of the Vaupes structural arch and concomitant breaching of the Purus structural arch. This event is hypothesized to have contributed to formation of the modern sternarchelline species, and to the formation of the modern basin-wide sternarchelline species assemblages. The results indicate that cladogenesis (speciation) and anagenesis (adaptive evolution) were decoupled processes in the evolution of Sternarchellini.

Voxel based analysis of recurrence dynamics in intracranial aneurysms after coiling

2017 ◽  
Vol 10 (6) ◽  
pp. 571-576 ◽  
Author(s):  
Marielle Ernst ◽  
Anika Buchholz ◽  
Romain Bourcier ◽  
Hubert Desal ◽  
Pierre-Yves Le Floch ◽  
...  
Keyword(s):  
Observation Interval ◽  
Three Dimensional ◽  
Growth Dynamics ◽  
Volumetric Analysis ◽  
Growth Patterns ◽  
Steady Increase ◽  
Residual Flow ◽  
Tof Mra ◽  
Incomplete Occlusion

BackgroundUnderstanding aneurysm growth is critical for the appropriate follow-up of patients after coil embolization and the need for retreatment. The purpose of the study was to stratify the growth dynamics of aneurysm recurrences after coiling by volumetric analysis and to determine predictive factors for aneurysm recurrences.MethodsSource images of follow-up three-dimensional time of flight MR angiography (ToF-MRA) scans were compared with the first post-interventional ToF-MRA scan and analyzed for residual flow after co-registration using ANALYZE-software. In the event of incomplete occlusion, the residual volume was segmented and calculated. Growth dynamic was determined for each aneurysm after embolization.ResultsWe analyzed 326 patients with 345 aneurysms from two centers. Each case had at least two ToF-MRA examinations after endovascular therapy. The mean observation interval was 59 months. Volumetric analysis of 1139 follow-up MRAs revealed that 218/345 aneurysms (63.2%) showed complete occlusion on initial follow-up imaging, and of these 95.0% remained stable. A steady increase in intra-aneurysmal flow was observed in 83/345 (24.1%). Less frequent observations were a steep increase (21/345; 6.1%) and a decrease (27/345; 7.8%). Independent predictors of increasing residual flow were greatest aneurysm diameter, total coil length, and incomplete occlusion.ConclusionsVolumetric analysis of registered three-dimensional ToF-MRA follow-up datasets allows the detection of different growth patterns with high precision, avoids the low inter-rater reliability, and represents a promising approach for future studies that include analysis of more complex predictors of residual flow. In cases of aneurysm recurrence after coiling, the major pattern seems to be a steady increase in intra-aneurysmal flow over several months.

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