scholarly journals Body-size trends of the extinct giant sharkCarcharocles megalodon: a deep-time perspective on marine apex predators

Paleobiology ◽  
2015 ◽  
Vol 41 (3) ◽  
pp. 479-490 ◽  
Author(s):  
Catalina Pimiento ◽  
Meghan A. Balk
Keyword(s):  
Body Size ◽  
Time Perspective ◽  
Selective Pressure ◽  
The Body ◽  
Shark Species ◽  
Apex Predators ◽  
Deep Time ◽  
Geologic Time ◽  
Marine Predators ◽  
Over Time

AbstractThe extinct sharkCarcharocles megalodonis one of the largest marine apex predators ever to exist. Nonetheless, little is known about its body-size variations through time and space. Here, we studied the body-size trends ofC. megalodonthrough its temporal and geographic range to better understand its ecology and evolution. Given that this species was the last of the megatooth lineage, a group of species that shows a purported size increase through time, we hypothesized thatC. megalodonalso displayed this trend, increasing in size over time and reaching its largest size prior to extinction. We found thatC. megalodonbody-size distribution was left-skewed (suggesting a long-term selective pressure favoring larger individuals), and presented significant geographic variation (possibly as a result of the heterogeneous ecological constraints of this cosmopolitan species) over geologic time. Finally, we found that stasis was the general mode of size evolution ofC. megalodon(i.e., no net changes over time), contrasting with the trends of the megatooth lineage and our hypothesis. Given thatC. megalodonis a relatively long-lived species with a widely distributed fossil record, we further used this study system to provide a deep-time perspective to the understanding of the body-size trends of marine apex predators. For instance, our results suggest that (1) a selective pressure in predatory sharks for consuming a broader range of prey may favor larger individuals and produce left-skewed distributions on a geologic time scale; (2) body-size variations in cosmopolitan apex marine predators may depend on their interactions with geographically discrete communities; and (3) the inherent characteristics of shark species can produce stable sizes over geologic time, regardless of the size trends of their lineages.

scholarly journals Tooth morphology elucidates shark evolution across the end-Cretaceous mass extinction

PLoS Biology ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. e3001108
Author(s):  
Mohamad Bazzi ◽  
Nicolás E. Campione ◽  
Per E. Ahlberg ◽  
Henning Blom ◽  
Benjamin P. Kear
Keyword(s):  
Mass Extinction ◽  
Mass Extinctions ◽  
Morphological Response ◽  
Geometric Morphometric ◽  
Deep Time ◽  
Predator Species ◽  
Geologic Time ◽  
Marine Predators ◽  
Time Diversity ◽  
Early Paleogene

Sharks (Selachimorpha) are iconic marine predators that have survived multiple mass extinctions over geologic time. Their prolific fossil record is represented mainly by isolated shed teeth, which provide the basis for reconstructing deep time diversity changes affecting different selachimorph clades. By contrast, corresponding shifts in shark ecology, as measured through morphological disparity, have received comparatively limited analytical attention. Here, we use a geometric morphometric approach to comprehensively examine tooth morphologies in multiple shark lineages traversing the catastrophic end-Cretaceous mass extinction—this event terminated the Mesozoic Era 66 million years ago. Our results show that selachimorphs maintained virtually static levels of dental disparity in most of their constituent clades across the Cretaceous–Paleogene interval. Nevertheless, selective extinctions did impact apex predator species characterized by triangular blade-like teeth. This is particularly evident among lamniforms, which included the dominant Cretaceous anacoracids. Conversely, other groups, such as carcharhiniforms and orectolobiforms, experienced disparity modifications, while heterodontiforms, hexanchiforms, squaliforms, squatiniforms, and †synechodontiforms were not overtly affected. Finally, while some lamniform lineages disappeared, others underwent postextinction disparity increases, especially odontaspidids, which are typified by narrow-cusped teeth adapted for feeding on fishes. Notably, this increase coincides with the early Paleogene radiation of teleosts as a possible prey source, and the geographic relocation of disparity sampling “hotspots,” perhaps indicating a regionally disjunct extinction recovery. Ultimately, our study reveals a complex morphological response to the end-Cretaceous mass extinction and highlights an event that influenced the evolution of modern sharks.

scholarly journals Dynamics of Calanus Copepodite Structure during Little Auks’ Breeding Seasons in Two Different Svalbard Locations

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1405
Author(s):  
Kaja Balazy ◽  
Emilia Trudnowska ◽  
Katarzyna Błachowiak-Samołyk
Keyword(s):  
Body Size ◽  
Zooplankton Community ◽  
Atlantic Water ◽  
The Body ◽  
Trophic Levels ◽  
Calanus Finmarchicus ◽  
Relative Role ◽  
Little Auk ◽  
Diving Depth ◽  
Over Time

Populations dynamics of key zooplankton species in the European Arctic, Calanus finmarchicus and Calanus glacialis (hereafter defined as Calanus) may be sensitive to climate changes, which in turn is of great importance for higher trophic levels. The aim of this study was to investigate the complete copepodite structure and dynamics of Calanus populations in terms of body size, phenology and their relative role in the zooplankton community over time in different hydrographic conditions (two fjords on the West Spitsbergen Shelf, cold Hornsund vs. warm Kongsfjorden), from the perspective of their planktivorous predator, the little auk. High-resolution zooplankton measurements (taken by nets and a laser optical plankton counter) were adapted to the timing of bird’s breeding in the 2015 and 2016 summer seasons, and to their maximal diving depth (≤50 m). In Hornsund, the share of the Calanus in zooplankton community was greater and the copepodite structure was progressively older over time, matching the little auks timing. The importance of Calanus was much lower in Kongsfjorden, as represented mainly by younger copepodites, presumably due to the Atlantic water advections, thus making this area a less favourable feeding ground. Our results highlight the need for further studies on the match/mismatch between Calanus and little auks, because the observed trend of altered age structure towards a domination of young copepodites and the body size reduction of Calanus associated with higher seawater temperatures may result in insufficient food availability for these seabirds in the future.

scholarly journals Interspecific hierarchies from aggressiveness and body size among the invasive alien hornet, Vespa velutina nigrithorax, and five native hornets in South Korea

2019 ◽  
Author(s):  
Ohseok Kwon ◽  
Moon Bo Choi
Keyword(s):  
Body Size ◽  
South Korea ◽  
The Body ◽  
High Rate ◽  
Aggressive Behaviors ◽  
Vespa Velutina ◽  
High Incidence ◽  
Spreading Rates ◽  
Over Time

AbstractThe range of the invasive alien hornet, Vespa velutina nigrithorax, has been continuously expanding since its invasion of Korea in 2003. Here, we compared the aggressive behaviors and body size of V. velutina nigrithorax with five native hornet species to identify the interspecific hierarchies that contributes to the spread of this species. Aggressive behaviors were classified into 11 categories and each interaction was scored as a win, loss, or tie. As a result, V. velutina was superior to V. simillima in 153 fights where V. velutina won 71% and showed a high incidence of threatening behavior. V. mandarinia outperformed V. velutina in 104 fights where V. mandarinia won 91% and grappling behavior was common. V. analis was superior to V. velutina in 67 fights where V. analis won 76% and showed a high amount of threatening behavior. V. crabro was superior to V. velutina in 93 fights where V. crabro won 73% and showed a high rate of threatening behavior. V. dybowskii was superior to V. velutina in 132 fights where V. dybowskii won 91%, and showed a high rate of threatening and grappling behaviors. The body size of V. velutina was larger than V. simillima (although not statistically significant) and smaller than all other Vespa species. Therefore, according to the results of this study, the low interspecific hierarchies of V. velutina seems to be a major cause of slower spreading rates than it has shown in Europe. However, over time, its density has gradually increased within the forest, in which it seems to be overcoming its disadvantages and expanding its range, possibly as large colonies and good flying abilities make it easier to secure food.

scholarly journals Different increase rate in body mass of two marten species due to climate warming potentially reinforces interspecific competition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Wereszczuk ◽  
Tim R. Hofmeester ◽  
Alexander Csanády ◽  
Tomislav Dumić ◽  
Morten Elmeros ◽  
...  
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Geographic Range ◽  
The Body ◽  
Stone Marten ◽  
Pine Marten ◽  
Adaptation To Climate Change ◽  
Geographical Patterns ◽  
Pine Martens ◽  
Over Time

AbstractMany species show spatial variation in body size, often associated with climatic patterns. Studying species with contrasting geographical patterns related to climate might help elucidate the role of different drivers. We analysed changes in the body mass of two sympatric medium-sized carnivores—pine marten (Martes martes) and stone marten (Martes foina)—across Europe over 59 years. The body mass of pine marten increased with decreasing latitude, whereas stone marten body mass varied in a more complex pattern across its geographic range. Over time, the average body mass of pine martens increased by 255 g (24%), while stone marten by 86 g (6%). The greatest increase of body mass along both martens’ geographic range was observed in central and southern Europe, where both species occur in sympatry. The body mass increase slowed down over time, especially in allopatric regions. The average pine/stone marten body mass ratio increased from 0.87 in 1960 to 0.99 in 2019, potentially strengthening the competition between them. Thus, a differential response in body size to several drivers over time might have led to an adaptive advantage for pine martens. This highlights the importance of considering different responses among interacting species when studying animal adaptation to climate change.

The Body Size of Headstarted and Wild Juvenile European Pond Turtles (Emys orbicularis)

2017 ◽  
Vol 25 (2) ◽  
pp. 161
Author(s):  
Sławomir Mitrus ◽  
Bartłomiej Najbar ◽  
Adam Kotowicz ◽  
Anna Najbar
Keyword(s):  
Body Size ◽  
The Body ◽  
Emys Orbicularis

scholarly journals The prevalence of underweight in 9–10-year-old schoolchildren in Liverpool: 1998–2006

2009 ◽  
Vol 12 (7) ◽  
pp. 953-956 ◽  
Author(s):  
Lynne M Boddy ◽  
Allan F Hackett ◽  
Gareth Stratton
Keyword(s):  
Mass Spectrum ◽  
Body Mass ◽  
The Body ◽  
Fitness Testing ◽  
Policy Makers ◽  
Substantial Problem ◽  
Prevalence Of Obesity ◽  
Grade 3 ◽  
The City ◽  
Over Time

AbstractObjectiveTo estimate the prevalence of underweight between 1998 and 2006 in Liverpool schoolchildren aged 9–10 years using recently published underweight cut-off points.Design and settingStature and body mass data collected at the LiverpoolSportsLinx project’s fitness testing sessions were used to calculate BMI.SubjectsData were available on 26 782 (n13 637 boys, 13 145 girls) participants.ResultsOverall underweight declined in boys from 10·3 % in 1998–1999 to 6·9 % in 2005–2006, and all sub-classifications of underweight declined, in particular grade 3 underweight, with the most recent prevalence being 0·1 %. In girls, the prevalence of underweight declined from 10·8 % in 1998–1999 to 7·5 % in 2005–2006. The prevalence of all grades of underweight was higher in girls than in boys. Underweight showed a fluctuating pattern across all grades over time for boys and girls, and overall prevalence in 2005–2006 represents over 200 children across the city.ConclusionsUnderweight may have reduced slightly from baseline, but remains a substantial problem in Liverpool, with the prevalence of overall underweight being relatively similar to the prevalence of obesity. The present study highlights the requirement for policy makers and funders to consider both ends of the body mass spectrum when fixing priorities in child health.

scholarly journals Detection of Acetaminophen and Its Glucuronide in Fingerprint by SALDI Mass Spectrometry Using Zeolite and Study of Time-Dependent Changes in Detected Ion Amount

Analytica ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 66-75
Author(s):  
Toshiki Horikoshi ◽  
Chihiro Kitaoka ◽  
Yosuke Fujii ◽  
Takashi Asano ◽  
Jiawei Xu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Glucuronic Acid ◽  
Laser Desorption ◽  
The Body ◽  
Time Dependent ◽  
Laser Desorption Ionization ◽  
Fingerprint Analysis ◽  
Desorption Ionization ◽  
Acid Conjugate ◽  
Over Time

The ingredients of an antipyretic (acetaminophen, AAP) and their metabolites excreted into fingerprint were detected by surface-assisted laser desorption ionization (SALDI) mass spectrometry using zeolite. In the fingerprint taken 4 h after AAP ingestion, not only AAP but also the glucuronic acid conjugate of AAP (GAAP), caffeine (Caf), ethenzamide (Eth), salicylamide (Sala; a metabolite of Eth), and urea were detected. Fingerprints were collected over time to determine how the amounts of AAP and its metabolite changed with time, and the time dependence of the peak intensities of protonated AAP and GAAP was measured. It was found that the increase of [GAAP+H]+ peak started later than that of [AAP+H]+ peak, reflecting the metabolism of AAP. Both AAP and GAAP reached maximum concentrations approximately 3 h after ingestion, and were excreted from the body with a half-life of approximately 3.3 h. In addition, fingerprint preservation was confirmed by optical microscopy, and fingerprint shape was retained even after laser irradiation of the fingerprint. Our method may be used in fingerprint analysis.

scholarly journals The isotopic niche of Atlantic, biting marine mammals and its relationship to skull morphology and body size

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Massimiliano Drago ◽  
Marco Signaroli ◽  
Meica Valdivia ◽  
Enrique M. González ◽  
Asunción Borrell ◽  
...  
Keyword(s):  
Body Size ◽  
Atlantic Ocean ◽  
Fisheries Management ◽  
Marine Mammals ◽  
Trophic Position ◽  
Sympatric Species ◽  
Isotopic Niche ◽  
Apex Predators ◽  
Skull Morphology ◽  
Ecosystem Based Fisheries Management

AbstractUnderstanding the trophic niches of marine apex predators is necessary to understand interactions between species and to achieve sustainable, ecosystem-based fisheries management. Here, we review the stable carbon and nitrogen isotope ratios for biting marine mammals inhabiting the Atlantic Ocean to test the hypothesis that the relative position of each species within the isospace is rather invariant and that common and predictable patterns of resource partitioning exists because of constrains imposed by body size and skull morphology. Furthermore, we analyze in detail two species-rich communities to test the hypotheses that marine mammals are gape limited and that trophic position increases with gape size. The isotopic niches of species were highly consistent across regions and the topology of the community within the isospace was well conserved across the Atlantic Ocean. Furthermore, pinnipeds exhibited a much lower diversity of isotopic niches than odontocetes. Results also revealed body size as a poor predictor of the isotopic niche, a modest role of skull morphology in determining it, no evidence of gape limitation and little overlap in the isotopic niche of sympatric species. The overall evidence suggests limited trophic flexibility for most species and low ecological redundancy, which should be considered for ecosystem-based fisheries management.

scholarly journals First record of Pachycrocuta brevirostris (Gervais, 1850) from Ukraine on the background of the European occurrence of the species

2021 ◽  
Author(s):  
Adrian Marciszak ◽  
Yuriy Semenov ◽  
Piotr Portnicki ◽  
Tamara Derkach
Keyword(s):  
Body Size ◽  
First Record ◽  
The Body ◽  
Crocuta Crocuta ◽  
Early Pleistocene ◽  
Eastern Asia ◽  
South Eastern

AbstractCranial material ofPachycrocuta brevirostrisfrom the late Early Pleistocene site of Nogaisk is the first record of this species in Ukraine. This large hyena was a representative of the Tamanian faunal complex and a single specialised scavenger in these faunas. The revisited European records list ofP.brevirostrisdocumented the presence of this species in 101 sites, dated in the range of 3.5–0.4 Ma. This species first disappeared in Africa, survived in Europe until ca. 0.8–0.7 Ma, and its last, relict occurrence was known from south-eastern Asia. The main reason of extinction ofP.brevirostrisprobably was the competition withCrocuta crocuta. The cave hyena was smaller, but its teeth were proportionally larger to the body size, better adapted to crushing bones and slicing meat, and could also hunt united in larger groups.

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