Mandibular force profiles and tooth morphology in growth series of Albertosaurus sarcophagus and Gorgosaurus libratus (Tyrannosauridae: Albertosaurinae) provide evidence for an ontogenetic dietary shift in tyrannosaurids

2021 ◽  
Author(s):  
François Therrien ◽  
Darla K. Zelenitsky ◽  
Jared T Voris ◽  
Kohei Tanaka
Keyword(s):  
Feeding Behavior ◽  
Feeding Strategy ◽  
Large Body ◽  
Biomechanical Properties ◽  
Bite Force ◽  
Growth Stages ◽  
Tooth Morphology ◽  
Growth Series ◽  
Dietary Shift ◽  
Force Profiles

The albertosaurines Albertosaurus sarcophagus and Gorgosaurus libratus are among the best represented tyrannosaurids, known from nearly complete growth series. These specimens provide an opportunity to study mandibular biomechanical properties and tooth morphology in order to infer changes in feeding behavior and bite force through ontogeny in tyrannosaurids. Mandibular force profiles reveal that the symphyseal region of albertosaurines is consistently stronger in bending than the middentary region, indicating that the anterior extremity of the jaws played an important role in prey capture and handling through ontogeny. The symphyseal region was better adapted to withstand torsional stresses than in most non-avian theropods, but not to the extent seen in Tyrannosaurus rex, suggesting that albertosaurine feeding behavior may have involved less bone crushing or perhaps relatively smaller prey than in T. rex. The constancy of these biomechanical properties at all known growth stages indicates that although albertosaurines maintained a similar feeding strategy through ontogeny, prey size/type had to change between juvenile and mature individuals. This ontogenetic dietary shift likely happened when individuals reached a mandibular length of ~58 cm, a size at which teeth shift from ziphodont to incrassate in shape and bite force begins to increase exponentially. The fact that large albertosaurines were capable of generating bite forces equivalent to similar-sized tyrannosaurines suggests that no significant differences in jaw closing musculature existed between the two clades and that the powerful bite of T. rex is the result of its large body size rather than of unique adaptations related to a specialized ecology.

scholarly journals Accuracy of mandibular force profiles for bite force estimation and feeding behavior reconstruction in extant and extinct carnivorans

2016 ◽  
Vol 219 (23) ◽  
pp. 3738-3749 ◽  
Author(s):  
François Therrien ◽  
Annie Quinney ◽  
Kohei Tanaka ◽  
Darla K. Zelenitsky
Keyword(s):  
Feeding Behavior ◽  
Bite Force ◽  
Force Estimation ◽  
Force Profiles

scholarly journals Exploring the role of gut microbiota in host feeding behavior among breeds in swine

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Yuqing He ◽  
Francesco Tiezzi ◽  
Jeremy Howard ◽  
Yijian Huang ◽  
Kent Gray ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Feeding Behavior ◽  
Growth Stages ◽  
Rrna Gene ◽  
Sequence Variants ◽  
Host Feeding ◽  
Microbial Composition ◽  
Large White ◽  
Rrna Gene Sequencing ◽  
Host Metabolism

Abstract Background The interplay between the gut microbiota and feeding behavior has consequences for host metabolism and health. The present study aimed to explore gut microbiota overall influence on feeding behavior traits and to identify specific microbes associated with the traits in three commercial swine breeds at three growth stages. Feeding behavior measures were obtained from 651 pigs of three breeds (Duroc, Landrace, and Large White) from an average 73 to 163 days of age. Seven feeding behavior traits covered the information of feed intake, feeder occupation time, feeding rate, and the number of visits to the feeder. Rectal swabs were collected from each pig at 73 ± 3, 123 ± 4, and 158 ± 4 days of age. DNA was extracted and subjected to 16 S rRNA gene sequencing. Results Differences in feeding behavior traits among breeds during each period were found. The proportion of phenotypic variances of feeding behavior explained by the gut microbial composition was small to moderate (ranged from 0.09 to 0.31). A total of 21, 10, and 35 amplicon sequence variants were found to be significantly (q-value < 0.05) associated with feeding behavior traits for Duroc, Landrace, and Large White across the three sampling time points. The identified amplicon sequence variants were annotated to five phyla, with Firmicutes being the most abundant. Those amplicon sequence variants were assigned to 28 genera, mainly including Christensenellaceae_R-7_group, Ruminococcaceae_UCG-004, Dorea, Ruminococcaceae_UCG-014, and Marvinbryantia. Conclusions This study demonstrated the importance of the gut microbial composition in interacting with the host feeding behavior and identified multiple archaea and bacteria associated with feeding behavior measures in pigs from either Duroc, Landrace, or Large White breeds at three growth stages. Our study provides insight into the interaction between gut microbiota and feeding behavior and highlights the genetic background and age effects in swine microbial studies.

scholarly journals Corn supplementation as a winter-feeding strategy alters maternal feeding behavior and endocrine profiles in mid- to late-gestating beef cows1

2018 ◽  
Vol 2 (suppl_1) ◽  
pp. S106-S111 ◽  
Author(s):  
Amelia R Tanner ◽  
Victoria C Kennedy ◽  
Marc L Bauer ◽  
Kendall C Swanson ◽  
James D Kirsch ◽  
...  
Keyword(s):  
Feeding Behavior ◽  
Feeding Strategy ◽  
Endocrine Profiles ◽  
Winter Feeding

scholarly journals Cope's Rule and Romer's theory: patterns of diversity and gigantism in eurypterids and Palaeozoic vertebrates

2009 ◽  
Vol 6 (2) ◽  
pp. 265-269 ◽  
Author(s):  
James C. Lamsdell ◽  
Simon J. Braddy
Keyword(s):  
Body Size ◽  
Environmental Factors ◽  
Feeding Strategy ◽  
Large Body ◽  
Large Body Size ◽  
Causal Mechanisms ◽  
Family Level ◽  
Cope’S Rule ◽  
Abiotic Environmental Factors

Gigantism is widespread among Palaeozoic arthropods, yet causal mechanisms, particularly the role of (abiotic) environmental factors versus (biotic) competition, remain unknown. The eurypterids (Arthropoda: Chelicerata) include the largest arthropods; gigantic predatory pterygotids (Eurypterina) during the Siluro-Devonian and bizarre sweep-feeding hibbertopterids (Stylonurina) from the Carboniferous to end-Permian. Analysis of family-level originations and extinctions among eurypterids and Palaeozoic vertebrates show that the diversity of Eurypterina waned during the Devonian, while the Placodermi radiated, yet Stylonurina remained relatively unaffected; adopting a sweep-feeding strategy they maintained their large body size by avoiding competition, and persisted throughout the Late Palaeozoic while the predatory nektonic Eurypterina (including the giant pterygotids) declined during the Devonian, possibly out-competed by other predators including jawed vertebrates.

scholarly journals Hippocampal Circuits for the Hunger-Dependent Control of Feeding Behaviour

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A540-A540
Author(s):  
Ryan Wei Shien Wee ◽  
Andrew MacAskill
Keyword(s):  
Feeding Behavior ◽  
Food Consumption ◽  
Calcium Imaging ◽  
Feeding Strategy ◽  
Ghrelin Receptor ◽  
Internal States ◽  
Decision Making Processes ◽  
Free Feeding ◽  
Motivated Behaviors

Abstract Background: Feeding behavior is a complex motivated behavior that requires organisms to integrate features of the environment, such as food availability and value, and internal states, such as hunger, in deliberating over the decision to eat. The hippocampus - a brain region classically thought to support spatial cognition and episodic memory - is increasingly recognised to contribute to such decision-making processes. This function makes the hippocampus a likely candidate in supporting the higher-order decisions that underpin motivated behaviors such as feeding. However, the role of the hippocampus during free-feeding behavior has not been examined. Methods and Results: To address this question, we used in vivo calcium imaging during feeding behavior in mice to monitor the neural activity of the ventral subiculum (vS) - one of the main output structures of the ventral hippocampus. In a free-feeding task, we found that the vS encoded the investigative approach phase of feeding behavior and that activity during this period correlated with the probability of transitioning from food investigation to consumption. Calcium imaging during an operant task confirmed the specific encoding of preparatory behaviour preceding food consumption. Furthermore, the sensitivity of vS to the hunger state could be mapped to vS neurons projecting to the nucleus accumbens (vS-NAc). Ghrelin - a hormone signalling the hunger state - altered synaptic transmission specifically in vS-NAc neurons, and molecular knockdown of the ghrelin receptor was required for the hunger sensitivity of vS-NAc. Consequently, both reducing ghrelin signalling in vS-NAc neurons through molecular knockdown and artificially elevating vS-NAc activity through optogenetics were sufficient to shift the feeding strategy of animals, effectively curtailing overall food consumption. Conclusion: In summary, these results provide evidence for a hippocampal circuit that integrates hunger state signals to regulate the decision to eat.

scholarly journals Selective Feeding by a Predatory Sea Star Across a Depth Gradient in Northern Patagonia, Chile

2021 ◽  
Vol 8 ◽  
Author(s):  
Ignacio Garrido ◽  
Luis Miguel Pardo ◽  
Ladd E. Johnson ◽  
Dirk Schories
Keyword(s):  
Feeding Behavior ◽  
Prey Selection ◽  
Feeding Strategy ◽  
Benthic Communities ◽  
Generalist Predator ◽  
Subtidal Zone ◽  
Polar Regions ◽  
Depth Gradient ◽  
Sea Star ◽  
Sea Stars

Sea stars often function as keystone predators in food webs of intertidal and subtidal communities, especially in temperate and sub-polar regions. In South America the sea star Cosmasterias lurida is distributed along both the Atlantic and Pacific coasts of Patagonia and is one of the most conspicuous and abundant benthic predators in the shallow subtidal zone (&lt;25 m). Its feeding strategy and prey selection are, however, still poorly known. This study describes the feeding behavior of C. lurida at a site in the Seno del Reloncaví (Chile), assessing its abundance, size and prey selection in the field relative to observed prey abundance and size along a bathymetric gradient. We hypothesized that C. lurida is a generalist predator, feeding on suitable prey according to their availability. However, we found that this predator only consumed a limited number (7 of 48) of potential prey species, primarily the slipper limpets Crepipatella spp. and the mussels Aulacomya ater and Mytilus chilensis. Electivity analysis revealed a clear preference for one mussel (A. ater) but not the other (M. chilensis) as well as depth-dependent selectivity for the slipper limpets, which changed from avoidance to preference with increasing depth. Sea star densities varied with depth, peaking between depths of 5 and 10 m, but the size of sea stars and the size of their prey did not vary significantly along a depth gradient. No significant correlations were found with the most commonly selected prey. These results would indicate that while this predator may be a generalist–opportunist, its feeding behavior is context-dependent and its high selectivity for certain species suggests that this sea star plays a key role structuring subtidal benthic communities in Patagonia.

Feeding behavior and dry matter digestibility in sheep fed first and second cut reed canary grass (Phalaris arundinacea L.)

2019 ◽  
Author(s):  
N. Tokita, ◽  
I. Yoshimura ◽  
T. Tokita
Keyword(s):  
Feeding Behavior ◽  
Crude Protein ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Growth Stages ◽  
Reed Canary Grass ◽  
Eating Time ◽  
Dry Matter Digestibility ◽  
Canary Grass ◽  
Female Sheep

We investigated the intake and digestibility of different reed canarygrass (RCG) growth stages by sheep. RCG was cultivated in an experimental field and harvested at the first and second cuts at each pre-blooming stage. Feeding behavior was monitored on adult female sheep, fed 3 kg each of fresh RCG three times daily. While the crude protein content and dry matter digestibility of RCG were significantly higher in leaf than in stem tissue of both first and second cut in harvesting times, neutral and acid detergent fiber contents were higher in stem than in leaf. The dry matter intake of RCG at the second cut (296.1g) was significantly higher than at the first cut (214.1 g). The eating time for consumption of RCG on dry matter at the second cut (54.9 min) was shorter than at the first cut (69.4 min). Consequently, at the second cut, the rate of biting (54.6 bites/min) was lower than at the first cut (64.8 bites/min). Bite size, expressed as dry matter intake per bite, ranged from 0.05 g at first cut to 0.10 g at second cut.

scholarly journals FOOD CONSUMPTION, FEED EFFICIENCY, METABOLIC RATE AND UTILIZATION OF GLUCOSE IN LINES OF TRIBOLIUM CASTANEUM SELECTED FOR 21-DAY PUPA WEIGHT

Genetics ◽  
1976 ◽  
Vol 83 (2) ◽  
pp. 393-407 ◽  
Author(s):  
Juan F Medrano ◽  
G A E Gall
Keyword(s):  
Metabolic Rate ◽  
Food Consumption ◽  
Tribolium Castaneum ◽  
Feed Efficiency ◽  
Large Body ◽  
Biological Efficiency ◽  
Growth Stages ◽  
Control Line ◽  
Selected Lines ◽  
Selection For

ABSTRACT Food consumption, feed efficiency, metabolic rate and glucose utilization were studied throughout development in one control (1C) and three selected lines (3, 9, 10) of Tribolium castaneum that had been subjected to long term selection for 21-day pupae weight. Growth rate, body composition, cellular growth and the activity of four dehydrogenase enzymes in the same lines have been reported (Medrano and Gall 1976).—Larva of selected lines consumed 1.2 times as much food as the control and gained an average of 2.9 times as much weight. The rapid growth of the selected lines was associated with a gross feed efficiency 20 to 30% above that for the control line. There was also a small but consistent improvement in the conversion of digested food. Average digestibility was higher for selected lines.—There was little apparent differentiation between the control and selected lines in metabolic rate/individual, but the rate measured on a per-unit weight basis was two- to three-fold greater for the control during the active growth stages. Respiratory quotients (R.Q.) of 1.0, indicative of carbohydrate oxidation, were observed through larval growth in all lines. Pupae at 21 days showed R.Q. values greater than 1.0, which were interpreted as resulting from a phenomenon in insects in which CO2 is released by pupae, in large bursts at irregular intervals. The rate constant of glucose oxidation, measured as the rate of C14 labelled CO2 respired during 2- to 6-hour incubation periods, was two- to three-fold higher in the control. In addition, the control line larvae expired 5% to 17% more of the ingested C14 as CO2. It was apparent that control line individuals maintained a much more active turnover of metabolites but without an effective retention of carbon as body substances. The results are discussed in support of the hypothesis that selection for large body size resulted in improved control mechanisms that influence the biological efficiency of growth in Tribolium.

Ontogeny and relationships of the Ordovician odontopleurid trilobite Ceratocara, with new species from Argentina and New York

1997 ◽  
Vol 71 (1) ◽  
pp. 108-125 ◽  
Author(s):  
Brian D. E. Chatterton ◽  
Gregory D. Edgecombe ◽  
Norberto E. Vaccari ◽  
Beatriz G. Waisfeld
Keyword(s):  
New York ◽  
Phylogenetic Analysis ◽  
New Species ◽  
San Juan ◽  
Growth Stages ◽  
Upper Ordovician ◽  
Growth Series ◽  
Middle Ordovician ◽  
Argentine Precordillera ◽  
A New Species

A growth series is described for a new species of Ceratocara Ramsköld, 1991, C. argentina, from the Upper Ordovician (Caradoc) part of the Las Aguaditas Formation, near Jáchal in San Juan Province, Argentine Precordillera. Another new species of Ceratocara, C. shawi, is described from the Middle Ordovician (lower Chazy) Crown Point Formation of New York. A phylogenetic analysis is presented for these species, other well-known Ordovician species of Ceratocara, and some Ordovician species of Ceratocephala, with Ceratocephalina tridens Whittington, 1956, as outgroup. The analysis presented supports the monophyly of both Ceratocara and Ceratocephala Warder, 1838, their divergence having occurred by the middle Arenig. The ontogenies of the Ceratocara species from Argentina and New York, complete from protaspid to holaspid growth stages, are some of the best preserved odontopleurid ontogenies described to date. Material of Ceratocephala triacantheis Whittington and Evitt, 1954, from the Crown Point Formation of the Chazy Group of New York, is discriminated from that of Ceratocara shawi.

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