scholarly journals DYNAMICS OF THE BODY SIZE EVOLUTION OF CROCODYLIFORMES

2018 ◽  
Author(s):  
William Gearty ◽  
◽  
Jonathan L. Payne
Keyword(s):  
Body Size ◽  
The Body ◽  
Size Evolution ◽  
Body Size Evolution

scholarly journals Giant lizards occupied herbivorous mammalian ecospace during the Paleogene greenhouse in Southeast Asia

2013 ◽  
Vol 280 (1763) ◽  
pp. 20130665 ◽  
Author(s):  
Jason J. Head ◽  
Gregg F. Gunnell ◽  
Patricia A. Holroyd ◽  
J. Howard Hutchison ◽  
Russell L. Ciochon
Keyword(s):  
Body Size ◽  
Competitive Exclusion ◽  
Elevated Temperatures ◽  
Middle Eocene ◽  
The Body ◽  
Metabolic Rates ◽  
Size Evolution ◽  
Dental Anatomy ◽  
Competition For Food ◽  
Body Size Evolution

Mammals dominate modern terrestrial herbivore ecosystems, whereas extant herbivorous reptiles are limited in diversity and body size. The evolution of reptile herbivory and its relationship to mammalian diversification is poorly understood with respect to climate and the roles of predation pressure and competition for food resources. Here, we describe a giant fossil acrodontan lizard recovered with a diverse mammal assemblage from the late middle Eocene Pondaung Formation of Myanmar, which provides a historical test of factors controlling body size in herbivorous squamates. We infer a predominately herbivorous feeding ecology for the new acrodontan based on dental anatomy, phylogenetic relationships and body size. Ranking body masses for Pondaung Formation vertebrates indicates that the lizard occupied a size niche among the larger herbivores and was larger than most carnivorous mammals. Paleotemperature estimates of Pondaung Formation environments based on the body size of the new lizard are approximately 2–5°C higher than modern. These results indicate that competitive exclusion and predation by mammals did not restrict body size evolution in these herbivorous squamates, and elevated temperatures relative to modern climates during the Paleogene greenhouse may have resulted in the evolution of gigantism through elevated poikilothermic metabolic rates and in response to increases in floral productivity.

scholarly journals New insights into the genetic mechanisms of body size evolution in Carnivora

2020 ◽  
Author(s):  
Xin Huang ◽  
Di Sun ◽  
Tianzhen Wu ◽  
Xing Liu ◽  
Shixia Xu ◽  
...  
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Rapid Evolution ◽  
Large Body ◽  
The Body ◽  
Molecular Evidence ◽  
Size Evolution ◽  
Body Size Evolution

Abstract Background The range of body sizes in Carnivora is unparalleled in any other mammalian order, with more than 130,000 times in body mass and 50 times in length. However, the molecular mechanisms underlying the huge difference in body size of Carnivora have not been explored so far. Results Herein, we performed a comparative genomics analysis of 20 carnivores to explore the genetic basis of great body size variation in carnivores. Phylogenetic generalized least squares (PGLS) revealed that 337 genes were significantly related to both head body length and body mass, these genes were defined as body size associated genes (BSAGs). Fourteen positively related BSAGs were found to be associated with obesity and three of which were identified to be under rapid evolution in the extremely large body-sized carnivores, which suggested that these obesity-related BSAGs might have driven the body size expansion in carnivores. Interestingly, 100 BSAGs were examined to be associated with cancer control in carnivores, particularly 15 cancer-related genes were found to be under rapid evolution in extremely large carnivores. These results strongly suggested that large body-sized carnivores might have evolved effective mechanism to resist cancer, which could be regarded as molecular evidence to support for the Peto’s paradox. For small carnivores, we identified 15 rapidly evolving genes and found six genes with fixed amino acid changes that were reported to reduce body size. Conclusion This study brings new insights into the molecular mechanisms that drove the diversifying evolution of body size in carnivores, and provides new target genes for exploring the mysteries of body size evolution in mammals.

scholarly journals Genomic insights into body size evolution in Carnivora support Peto’s paradox

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xin Huang ◽  
Di Sun ◽  
Tianzhen Wu ◽  
Xing Liu ◽  
Shixia Xu ◽  
...  
Keyword(s):  
Body Size ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Rapid Evolution ◽  
Generalized Least Squares ◽  
The Body ◽  
Molecular Evidence ◽  
Large Carnivores ◽  
Size Evolution ◽  
Body Size Evolution

Abstract Background The range of body sizes in Carnivora is unparalleled in any other mammalian order—the heaviest species is 130,000 times heavier than the lightest and the longest species is 50 times longer than the shortest. However, the molecular mechanisms underlying these huge differences in body size have not been explored. Results Herein, we performed a comparative genomics analysis of 20 carnivores to explore the evolutionary basis of the order’s great variations in body size. Phylogenetic generalized least squares (PGLS) revealed that 337 genes were significantly related to both head body length and body mass; these genes were defined as body size associated genes (BSAGs). Fourteen positively-related BSAGs were found to be associated with obesity, and three of these were under rapid evolution in the extremely large carnivores, suggesting that these obesity-related BSAGs might have driven the body size expansion in carnivores. Interestingly, 100 BSAGs were statistically significantly enriched in cancer control in carnivores, and 15 of which were found to be under rapid evolution in extremely large carnivores. These results suggested that large carnivores might have evolved an effective mechanism to resist cancer, which could be regarded as molecular evidence to support Peto’s paradox. For small carnivores, we identified 15 rapidly evolving genes and found six genes with fixed amino acid changes that were reported to reduce body size. Conclusions This study brings new insights into the molecular mechanisms that drove the diversifying evolution of body size in carnivores, and provides new target genes for exploring the mysteries of body size evolution in mammals.

scholarly journals An Italian dinosaur Lagerstätte reveals the tempo and mode of hadrosauriform body size evolution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alfio Alessandro Chiarenza ◽  
Matteo Fabbri ◽  
Lorenzo Consorti ◽  
Marco Muscioni ◽  
David C. Evans ◽  
...  
Keyword(s):  
Body Size ◽  
Mediterranean Region ◽  
Type Specimen ◽  
Skeletal Remains ◽  
The Body ◽  
Evolutionary Trend ◽  
Island Rule ◽  
Size Evolution ◽  
North Eastern ◽  
Body Size Evolution

AbstractDuring the latest Cretaceous, the European Archipelago was characterized by highly fragmented landmasses hosting putative dwarfed, insular dinosaurs, claimed as fossil evidence of the “island rule”. The Villaggio del Pescatore quarry (north-eastern Italy) stands as the most informative locality within the palaeo-Mediterranean region and represents the first, multi-individual Konservat-Lagerstätte type dinosaur-bearing locality in Italy. The site is here critically re-evaluated as early Campanian in age, thus preceding the final fragmentation stages of the European Archipelago, including all other European localities preserving hypothesized dwarfed taxa. New skeletal remains allowed osteohistological analyses on the hadrosauroid Tethyshadros insularis indicating subadult features in the type specimen whereas a second, herein newly described, larger individual is likely somatically mature. A phylogenetic comparative framework places the body-size of T. insularis in range with other non-hadrosaurid Eurasian hadrosauroids, rejecting any significant evolutionary trend towards miniaturisation in this clade, confuting its ‘pygmy’ status, and providing unmatched data to infer environmentally-driven body-size trends in Mesozoic dinosaurs.

Dinosaur Macroevolution and Macroecology

2018 ◽  
Vol 49 (1) ◽  
pp. 379-408 ◽  
Author(s):  
Roger B.J. Benson
Keyword(s):  
Life History ◽  
Body Size ◽  
Reproductive Biology ◽  
Fossil Record ◽  
Structural Diversity ◽  
Body Plan ◽  
Adaptive Landscape ◽  
Species Diversification ◽  
Size Evolution ◽  
Body Size Evolution

Dinosaurs were large-bodied land animals of the Mesozoic that gave rise to birds. They played a fundamental role in structuring Jurassic–Cretaceous ecosystems and had physiology, growth, and reproductive biology unlike those of extant animals. These features have made them targets of theoretical macroecology. Dinosaurs achieved substantial structural diversity, and their fossil record documents the evolutionary assembly of the avian body plan. Phylogeny-based research has allowed new insights into dinosaur macroevolution, including the adaptive landscape of their body size evolution, patterns of species diversification, and the origins of birds and bird-like traits. Nevertheless, much remains unknown due to incompleteness of the fossil record at both local and global scales. This presents major challenges at the frontier of paleobiological research regarding tests of macroecological hypotheses and the effects of dinosaur biology, ecology, and life history on their macroevolution.

scholarly journals The developmental and physiological basis of body size evolution in an insect

2001 ◽  
Vol 268 (1476) ◽  
pp. 1589-1593 ◽  
Author(s):  
Louis J. D'Amico ◽  
Goggy Davidowitz ◽  
H. Frederik Nijhout
Keyword(s):  
Body Size ◽  
Physiological Basis ◽  
Size Evolution ◽  
Body Size Evolution

scholarly journals Evolution of body size in anteaters and sloths (Xenarthra, Pilosa): phylogeny, metabolism, diet and substrate preferences

2015 ◽  
Vol 106 (4) ◽  
pp. 289-301 ◽  
Author(s):  
N. Toledo ◽  
M.S. Bargo ◽  
S.F. Vizcaíno ◽  
G. De Iuliis ◽  
F. Pujos
Keyword(s):  
Body Size ◽  
Fossil Record ◽  
Dietary Habits ◽  
Decomposition Analysis ◽  
Size Variation ◽  
The Body ◽  
Phylogenetic Pattern ◽  
Substrate Preferences ◽  
Size Evolution ◽  
Main Factor

ABSTRACTPilosa include anteaters (Vermilingua) and sloths (Folivora). Modern tree sloths are represented by two genera, Bradypus and Choloepus (both around 4–6 kg), whereas the fossil record is very diverse, with approximately 90 genera ranging in age from the Oligocene to the early Holocene. Fossil sloths include four main clades, Megalonychidae, Megatheriidae, Nothrotheriidae, and Mylodontidae, ranging in size from tens of kilograms to several tons. Modern Vermilingua are represented by three genera, Cyclopes, Tamandua and Myrmecophaga, with a size range from 0.25 kg to about 30 kg, and their fossil record is scarce and fragmentary. The dependence of the body size on phylogenetic pattern of Pilosa is analysed here, according to current cladistic hypotheses. Orthonormal decomposition analysis and Abouheif C-mean were performed. Statistics were significantly different from the null-hypothesis, supporting the hypothesis that body size variation correlates with the phylogenetic pattern. Most of the correlation is concentrated within Vermilingua, and less within Mylodontidae, Megatheriidae, Nothrotheriidae and Megalonychidae. Influence of basal metabolic rate (BMR), dietary habits and substrate preference is discussed. In anteaters, specialised insectivory is proposed as the primary constraint on body size evolution. In the case of sloths, mylodontids, megatheriids and nothrotheriids show increasing body size through time; whereas megalonychids retain a wider diversity of sizes. Interplay between BMR and dietary habits appears to be the main factor in shaping evolution of sloth body size.

scholarly journals Mammal body size evolution in North America and Europe over 20 Myr: similar trends generated by different processes

2017 ◽  
Vol 284 (1849) ◽  
pp. 20162361 ◽  
Author(s):  
Shan Huang ◽  
Jussi T. Eronen ◽  
Christine M. Janis ◽  
Juha J. Saarinen ◽  
Daniele Silvestro ◽  
...  
Keyword(s):  
Body Size ◽  
North America ◽  
Biological Properties ◽  
Species Selection ◽  
Minimum Size ◽  
Extinction Rate ◽  
Large Herbivores ◽  
Size Evolution ◽  
Geographical Regions ◽  
Body Size Evolution

Because body size interacts with many fundamental biological properties of a species, body size evolution can be an essential component of the generation and maintenance of biodiversity. Here we investigate how body size evolution can be linked to the clade-specific diversification dynamics in different geographical regions. We analyse an extensive body size dataset of Neogene large herbivores (covering approx. 50% of the 970 species in the orders Artiodactyla and Perissodactyla) in Europe and North America in a Bayesian framework. We reconstruct the temporal patterns of body size in each order on each continent independently, and find significant increases of minimum size in three of the continental assemblages (except European perissodactyls), suggesting an active selection for larger bodies. Assessment of trait-correlated birth-death models indicates that the common trend of body size increase is generated by different processes in different clades and regions. Larger-bodied artiodactyl species on both continents tend to have higher origination rates, and both clades in North America show strong links between large bodies and low extinction rate. Collectively, our results suggest a strong role of species selection and perhaps of higher-taxon sorting in driving body size evolution, and highlight the value of investigating evolutionary processes in a biogeographic context.

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