The cushioning function of woodpecker’s jaw apparatus during the pecking process

2021 ◽  
pp. 1-11
Author(s):  
Peng Xu ◽  
Yikun Ni ◽  
Shan Lu ◽  
Sijian Liu ◽  
Xue Zhou ◽  
...  
Keyword(s):  
Jaw Apparatus

Jaw Apparatus and Feeding Mechanics of Typhlops (Ophidia: Typhlopidae): a Reconsideration

2011 ◽  
Vol 4 (2) ◽  
pp. 120-127 ◽  
Author(s):  
Nikolai N. Iordansky
Keyword(s):  
Lower Jaw ◽  
Jaw Apparatus ◽  
Feeding Mechanics ◽  
Cranial Kinesis

The cranial kinesis and movements of the lower jaw in Typhlops are analyzed, with special emphasis placed on the functions of the jugomandibular ligament. The musculature of the Typhlops jaw apparatus is described. The role of movements of the quadrato-mandibular and palato-maxillary systems in feeding mechanics and functioning of the jaw apparatus muscles is discussed.

scholarly journals Have Niche, Will Travel. New Means of Linking Diet and Ecomorphology Reveals Niche Conservatism in Freshwater Cottoid Fishes

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
T J Buser ◽  
D L Finnegan ◽  
A P Summers ◽  
M A Kolmann
Keyword(s):  
Niche Conservatism ◽  
Freshwater Species ◽  
Evolutionary Transitions ◽  
Adaptive Diversification ◽  
Functional Aspects ◽  
Ecological Evolution ◽  
Jaw Apparatus ◽  
Cottoid Fishes ◽  
Freshwater Habitats ◽  
Dietary Niche

Synopsis Evolutionary transitions between habitats have been catalysts for some of the most stunning examples of adaptive diversification, with novel niches and new resources providing ecological opportunity for such radiations. In aquatic animals, transitions from saltwater to freshwater habitats are rare, but occur often enough that in the Neotropics for example, marine-derived fishes contribute noticeably to regional ichthyofaunal diversity. Here, we investigate how morphology has evolved in a group of temperate fishes that contain a marine to freshwater transition: the sculpins (Percomorpha; Cottoidea). We devised a novel method for classifying dietary niche and relating functional aspects of prey to their predators. Coupled with functional measurements of the jaw apparatus in cottoids, we explored whether freshwater sculpins have fundamentally changed their niche after invading freshwater (niche lability) or if they retain a niche similar to their marine cousins (niche conservatism). Freshwater sculpins exhibit both phylogeographical and ecological signals of phylogenetic niche conservatism, meaning that regardless of habitat, sculpins fill similar niche roles in either saltwater or freshwater. Rather than competition guiding niche conservatism in freshwater cottoids, we argue that strong intrinsic constraints on morphological and ecological evolution are at play, contra to other studies of diversification in marine-derived freshwater fishes. However, several intertidal and subtidal sculpins as well as several pelagic freshwater species from Lake Baikal show remarkable departures from the typical sculpin bauplan. Our method of prey categorization provides an explicit, quantitative means of classifying dietary niche for macroevolutionary studies, rather than relying on somewhat arbitrary means used in previous literature.

scholarly journals Gene coexpression networks reveal molecular interactions underlying cichlid jaw modularity

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Pooja Singh ◽  
Ehsan Pashay Ahi ◽  
Christian Sturmbauer
Keyword(s):  
In Silico ◽  
Regulatory Networks ◽  
Evolutionary Significance ◽  
Cichlid Species ◽  
Cichlid Fishes ◽  
Gene Coexpression ◽  
Modular Evolution ◽  
Jaw Apparatus ◽  
Coexpression Networks ◽  
Pharyngeal Jaw

Abstract Background The oral and pharyngeal jaw of cichlid fishes are a classic example of evolutionary modularity as their functional decoupling boosted trophic diversification and contributed to the success of cichlid adaptive radiations. Most studies until now have focused on the functional, morphological, or genetic aspects of cichlid jaw modularity. Here we extend this concept to include transcriptional modularity by sequencing whole transcriptomes of the two jaws and comparing their gene coexpression networks. Results We show that transcriptional decoupling of gene expression underlies the functional decoupling of cichlid oral and pharyngeal jaw apparatus and the two units are evolving independently in recently diverged cichlid species from Lake Tanganyika. Oral and pharyngeal jaw coexpression networks reflect the common origin of the jaw regulatory program as there is high preservation of gene coexpression modules between the two sets of jaws. However, there is substantial rewiring of genetic architecture within those modules. We define a global jaw coexpression network and highlight jaw-specific and species-specific modules within it. Furthermore, we annotate a comprehensive in silico gene regulatory network linking the Wnt and AHR signalling pathways to jaw morphogenesis and response to environmental cues, respectively. Components of these pathways are significantly differentially expressed between the oral and pharyngeal jaw apparatus. Conclusion This study describes the concerted expression of many genes in cichlid oral and pharyngeal jaw apparatus at the onset of the independent life of cichlid fishes. Our findings suggest that – on the basis of an ancestral gill arch network—transcriptional rewiring may have driven the modular evolution of the oral and pharyngeal jaws, highlighting the evolutionary significance of gene network reuse. The gene coexpression and in silico regulatory networks presented here are intended as resource for future studies on the genetics of vertebrate jaw morphogenesis and trophic adaptation.

scholarly journals DETERMINATION OF THE STRUCTURE OF ACUTE INJURY OF TEMPORARY AND PERMANENT FRONTAL TEETH IN CHILDREN, ANALYSIS OF DIAGNOSTIC AND TREATMENT MEASURES AND THEIR EFFECTS

2020 ◽  
Vol 73 (4) ◽  
pp. 737-742
Author(s):  
Valentina P. Trufanova ◽  
Olha V. Sheshukova ◽  
Natalia A. Lyakhova ◽  
Tetiana V. Polishchuk ◽  
Sofia S. Bauman ◽  
...  
Keyword(s):  
Self Regulation ◽  
Pediatric Dentistry ◽  
Permanent Tooth ◽  
Acute Injury ◽  
Permanent Teeth ◽  
Traumatic Injuries ◽  
Acute Injuries ◽  
Jaw Apparatus ◽  
Treatment Measures

The aim: To determine the structure of acute injuries of temporary and permanent frontal teeth in children, to analyze the applied diagnostic and treatment measures for acute tooth trauma and to investigate their effectiveness. Materials and methods: The subject of the study were 31 children aged 2-12 years with acute temporary and permanent tooth trauma. Methods: clinical (radiological, thermodiagnosis), medical and statistical. Results: The number of injured permanent teeth was greater than the number of injured temporary teeth. The pattern of temporary and permanent tooth injuries differed, so in temporary teeth dislocations were observed, and in permanent teeth fractures prevailed over dislocations. In our opinion, this is due to the peculiarities of the anatomy of the temporary teeth. Usually, the therapeutic tactics of acute temporary teeth injuries is to remove them, despite their important role in the growth and development of jaws, physiological formation and eruption of permanent teeth. The therapeutic tactics of dynamic observation in the case of intrusive dislocation of the temporary tooth were selected in the clinic of the Department of Pediatric Dentistry. In some cases, with a slight change in the position of the temporary tooth, self-regulation of its position was observed, in other cases the tooth remained dystopic, but its viability remained in 50% of cases. Therapeutic tactics of acute injuries of permanent teeth were selected according to the type of trauma. In the case of permanent tooth dislocation, with a slight change in its position, tooth immobilization was carried out by splinting with fiberglass tape and photopolymer composite material. Conclusions: Our observations have shown that the complex of modern specialized medical care for the affected children with acute traumatic injuries of the teeth should be guided by their preservation, which ensures the subsequent normal formation of the dental-jaw apparatus. To ensure these conditions, a long, reliable immobilization of the damaged tooth is required as soon as possible after injury.

scholarly journals Jaw musculature of Cyclarhis gujanensis (Aves: Vireonidae)

2015 ◽  
Vol 75 (3) ◽  
pp. 655-661 ◽  
Author(s):  
DM. Previatto ◽  
SR. Posso
Keyword(s):  
Functional Anatomy ◽  
Feeding Apparatus ◽  
Temporal Fossa ◽  
Jaw Muscles ◽  
Number Of Components ◽  
Caudal Portion ◽  
Jaw Apparatus ◽  
Adductor Muscles ◽  
Anatomical Knowledge ◽  
Jaw Musculature

AbstractCyclarhis gujanensis is a little bird which feeds on high number of large preys, such frogs, lizards, snakes, bats and birds. As there are few studies on the cranial anatomy of this species, we aimed to describe the cranial myology to contribute to the anatomical knowledge of this species and to make some assumptions about functional anatomy. Thus, we described the muscles from the jaw apparatus (external and internal adductor muscles, the muscles of the pterygoid system and the depressor muscles of the mandible). The adductor system is the greatest and multipinulated, particularly in its origin in the caudal portion of the temporal fossa. The depressor jaw muscles systems are enlarged with many components in complexity. The most of jaw apparatus muscles are short, but the strength (biting or crushing forces) from short feeding apparatus fibers probably is increased by high number of components and pinnulation. These anatomical aspects of the muscles indicate a considerable force in the jaws, without which C. gujanensis probably could not cut their prey into smaller pieces. However, functional approaches to analysis of forces of the muscle fibers are needed to corroborate / refute the hypotheses mentioned above.

scholarly journals Jaw elements in Plumulites bengtsoni confirm that machaeridians are extinct armoured scaleworms

2019 ◽  
Vol 286 (1907) ◽  
pp. 20191247 ◽  
Author(s):  
Luke A. Parry ◽  
Gregory D. Edgecombe ◽  
Dan Sykes ◽  
Jakob Vinther
Keyword(s):  
Phylogenetic Analysis ◽  
Early Evolution ◽  
The Body ◽  
Common Origin ◽  
Discrete Elements ◽  
Crown Group ◽  
Total Group ◽  
Early Ordovician ◽  
Jaw Apparatus ◽  
Competing Hypotheses

Machaeridians are Palaeozoic animals that are dorsally armoured with serialized, imbricating shell plates that cover or enclose the body. Prior to the discovery of an articulated plumulitid machaeridian from the Early Ordovician of Morocco that preserved unambiguous annelid characters (segmental parapodia with chaetae), machaeridians were a palaeontological mystery, having been previously linked to echinoderms, barnacles, tommotiids (putative stem-group brachiopods) or molluscs. Although the annelid affinities of machaeridians are now firmly established, their position within the phylum and relevance for understanding the early evolution of Annelida is less secure, with competing hypotheses placing Machaeridia in the stem or deeply nested within the crown group of annelids. We describe a scleritome of Plumulites bengtsoni from the Fezouata Formation of Morocco that preserves an anterior jaw apparatus consisting of at least two discrete elements that exhibit growth lines. Although jaws have multiple independent origins within the annelid crown group, comparable jaws are present only within Phyllodocida, the clade that contains modern aphroditiforms (scaleworms and relatives). Phylogenetic analysis places a monophyletic Machaeridia within the crown group of Phyllodocida in total-group Aphroditiformia, consistent with a common origin of machaeridian shell plates and scaleworm elytrae. The inclusion of machaeridians in Aphroditiformia truncates the ghost lineage of Phyllodocida by almost a hundred million years.

Biomechanical features of the bill and and jaw apparatus of cuckoos, turacos and the hoatzin in relation to food acquisition and processing

Ostrich ◽  
2003 ◽  
Vol 74 (1-2) ◽  
pp. 48-57 ◽  
Author(s):  
Leonid P Korzun ◽  
Christian Erard ◽  
Jean-Pierre Gasc ◽  
Felix J Dzerzhinsky
Keyword(s):  
Food Acquisition ◽  
Jaw Apparatus ◽  
Biomechanical Features

VI.—Features of Placoderm Diversification and the Evolution of the Arthrodire Feeding Mechanism.

1969 ◽  
Vol 68 (6) ◽  
pp. 123-170 ◽  
Author(s):  
Roger S. Miles
Keyword(s):  
Fossil Record ◽  
Anterior Part ◽  
Parallel Evolution ◽  
Good Evidence ◽  
Point Of View ◽  
Vertical Movements ◽  
Feeding Mechanism ◽  
Jaw Apparatus ◽  
History Of ◽  
Functional Point

SynopsisThe initial adaptive radiation of the Placodermi took place rapidly following the development of the basic placoderm adaptive complex after the ancestral scale covering of the trunk fused into a rigid shield, and not long before the group appears in the fossil record in the Lower Devonian. The radiation was mainly concerned with different ways of living in the benthos of a variety of marine and fresh-water environments; a few nektonic species appear late in the history of the Arthrodira. The fossil record shows the evolution of the orders in their adaptive zones. The zones become increasingly distinct as the orders evolve and become more specific in their adaptations, and the arthrodire, antiarch and rhenanid zones segregate into successively occupied sub-zones. The evolution of the Placodermi has been previously described in terms of improvements in the locomotor mechanism by an analysis of changes in the trunk-armour and pectoral fins. A more detailed description can be given by considering the feeding mechanism as well; this is particularly true of the largest order, the Arthrodira. Study of the feeding mechanism involves the cervical joints as well as the jaws and gnathals. The cervical joints had the same functions in feeding as the anterior part of the vertebral column (“the neck”) in many higher fish. In arthrodires jaw action involved vertical movements of the mandibular lever; the upper jaw apparatus is comparable to the rigid palatoquadrate-maxillary complex of primitive bony fish. The mandible was transformed into a bent lever inBrachyosteusby the development of a small “coronoid” process, but the arthrodire jaw apparatus remained undeveloped in comparison with Actinopterygii and Elasmobranchii. Arthrodire jaw suspension was autostylic. Evidence from the Rhenanida and Ptyctodontida has been interpreted to suggest that this condition was secondary, and that primitive placoderms had an elasmobranch or holocephalan-like palatoquadrate with hyostylic suspension. This view is not entirely supported by the state of the palatoquadrate in primitive arthrodires, but there is no good evidence that placoderms had a complete, open spiracular gill-slit (the aphethoyoid condition). Arthrodire phylogeny cannot yet be described in vertical lines, but four successive levels of organization of increasing efficiency can be recognized; the actinolepid, phlyctaenaspid, coccosteomorph and pachyosteomorph levels. These levels can be defined by simple characters relating to broad adaptations in the locomotor and feeding mechanisms. Evolutionary trends in the Arthrodira include the enlargement of the scapulocoracoid and base of the pectoral fin and the reduction of the spinal plate and flank armour, as the fish gain better control in the water and more myomeres become available for use in swimming; and the enlargement of the nuchal gap and development of the cranio-thoracic joint as powerful muscles are developed to raise the head to give a wide gape, accompanied by the specialization of the gnathals for different modes of feeding. Some of these trends are reversed in compressed, nektonic species. The description of arthrodire phylogeny in terms of changes that can be understood from a functional point of view reveals interesting examples of mosaic and parallel evolution.Parabelosteusn.gen. is erected.

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