scholarly journals Anatomy, functional morphology, evolutionary ecology and systematics of the invasive gastropod Cipangopaludina japonica (Viviparidae: Bellamyinae)

2016 ◽  
Vol 85 (2) ◽  
pp. 235-263 ◽  
Author(s):  
Bert Van Bocxlaer ◽  
Ellen E. Strong
Keyword(s):  
Functional Morphology ◽  
Evolutionary Ecology ◽  
Distribution Patterns ◽  
Reproductive Organs ◽  
Japanese Species ◽  
Shell Size ◽  
High Fecundity ◽  
Form And Function ◽  
Morphometric Analyses ◽  
And Function

The anatomy, functional morphology and evolutionary ecology of the Viviparidae, and the subfamily Bellamyinae in particular, are incompletely known. Partly as a result, genealogical relationships within the family remain poorly understood. Because of this lack in knowledge, few informed hypotheses exist on ancestral states, how differences in body plans between the subfamilies evolved, and how the peculiar biogeographic distribution patterns of viviparids have arisen. Here we document the anatomy, morphology, life history and systematics of Cipangopaludina japonica, a Japanese species that has been introduced into North America, to resolve taxonomic confusion and to improve our understanding of how form and function are related in bellamyines. Anatomical and histological examinations demonstrate marked differences between C. japonicaand other bellamyines in the radula, salivary gland, kidney, nerve ring and reproductive organs. Substantial differences also exist between male and female body organization, but conchological differences between sexes in semi-landmark morphometric analyses are limited. The volume of the brood pouch of females, and hence body and shell size, appear to be good predictors of reproductive success, and the species’ ecological versatility may relate to high fecundity and the ability to alternate between feeding modes. Comparing our observations on C. japonicawith other viviparids and basal Architaenioglossa, we identify several persistent misinterpretations in the literature on how form and function are related in viviparids, not in the least as to female reproductive anatomy. Our reinterpretations improve understanding of the evolution of Viviparidae and its subfamilies, and hopefully will allow future workers to isolate key traits that shaped the evolution of viviparids at the taxonomic levels of their interest for more detailed studies.

Functional morphology of the pretarsus in larval Thysanoptera

1972 ◽  
Vol 50 (6) ◽  
pp. 751-766 ◽  
Author(s):  
B. S. Heming
Keyword(s):  
Blood Pressure ◽  
Functional Morphology ◽  
Form And Function ◽  
Pull Out ◽  
Depressor Muscle ◽  
And Function

Legs of larval thrips differ in form and function from those of the adults. The tarsal depressor muscle and tibial gland of the adult are absent, the trochanter and tarsus are fused to the femur and tibia, respectively, and the relative sizes and shapes of the remaining parts differ.Contraction of the pretarsal depressor muscle elevates and flattens the unguitractor plate and flexes the ungues laterally and downward. Extenders associated with the bases of the ungues rotate outward and pull out and spread the arolium. This subsequently inflates with blood pressure. When the depressor muscle relaxes, the recoil of two stretched restraining tendons originating on the tibiotarsal walls and inserting proximally into the unguitractor apodeme returns the unguitractor plate to its resting position. The ungues approach each other anteriorly and the extenders flip back into the pretarsus, pulling the arolium within the unguitractor plate as the latter rolls up longitudinally. Minor differences in pretarsal function existing between larvae of the two suborders are indicated.Replacement of the first- by the second-instar pretarsus is described and an explanation is offered for the origin of the divergence between larval and imaginal mechanisms.

scholarly journals Reproductive Ontogeny and the Evolution of Morphological Diversity in Conifers and Other Plants

2019 ◽  
Vol 59 (3) ◽  
pp. 548-558 ◽  
Author(s):  
A B Leslie ◽  
J M Losada
Keyword(s):  
Morphological Evolution ◽  
Morphological Diversity ◽  
Developmental Rate ◽  
Reproductive Organs ◽  
Developmental Trajectory ◽  
Evolutionary Significance ◽  
Developmental Patterns ◽  
Functional Roles ◽  
Form And Function ◽  
And Function

Abstract Biologists often study morphological evolution through form and function relationships. But biological structures can perform multiple functional roles, complicating efforts to understand the evolutionary significance of any one relationship. Plant reproductive organs perform multiple roles in a sequence, however, which provides a unique opportunity to understand how structures evolve to meet multiple functional demands. Using conifers as a study group, we discuss how a shared developmental trajectory links the performance of sequential functional roles. Variation in development among lineages can underlie morphological diversity; pollination-stage seed cones in Pinaceae conifers function similarly but show diverse forms reflecting differences in developmental rate. As cones develop further, the morphologies that they use to perform later functional roles are influenced by the specific developmental patterns used to meet earlier demands, which may ultimately limit morphological diversity. However, we also show how selective pressures relating to the final functional stage (seed dispersal) may influence cone anatomy and morphology over all previous stages, highlighting the complex linkages among form, function, and development. We end by discussing the potential relationships between functional ontogeny and morphological disparity in plant reproductive structures more broadly, suggesting that the complex functional roles associated with seed plant reproduction probably underlie the high disparity in this group.

Virtual Functional Morphology: Novel Approaches to the Study of Craniofacial Form and Function

2012 ◽  
Vol 39 (4) ◽  
pp. 521-535 ◽  
Author(s):  
Paul O’Higgins ◽  
Laura C. Fitton ◽  
Roger Phillips ◽  
JunFen Shi ◽  
Jia Liu ◽  
...  
Keyword(s):  
Functional Morphology ◽  
Form And Function ◽  
Novel Approaches ◽  
And Function

The heterodonty of Albertosaurus sarcophagus and Tyrannosaurus rex: biomechanical implications inferred through 3-D modelsThis article is one of a series of papers published in this Special Issue on the theme Albertosaurus.

2010 ◽  
Vol 47 (9) ◽  
pp. 1253-1261 ◽  
Author(s):  
Miriam Reichel
Keyword(s):  
Stress Distribution ◽  
Yield Criterion ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Distribution Patterns ◽  
Shear Stresses ◽  
Form And Function ◽  
Southern Alberta ◽  
Tooth Form ◽  
And Function

The objective of this study is to analyze how different crown morphologies and different root lengths respond to stresses generated by the bite forces of Albertosaurus sarcophagus and Tyrannosaurus rex . Six well-preserved teeth of A. sarcophagus from the Albertosaurus bonebed in Dry Island Park (southern Alberta) were selected to study their biomechanics, and T. rex teeth were included for comparison. The three-dimensional (3-D) models were obtained through computerized tomography (CT) scanning and 3-D digitizing. Finite element analyses were performed in Strand7®. Bite forces for Albertosaurus and Tyrannosaurus were calculated based on cranial and jaw proportions. The results were viewed with the Tresca yield criterion. The ratios of shear stresses observed along the mesio-distal versus labio-lingual axes of all models allows the identification of similar stress distribution patterns in the upper and lower jaws of Albertosaurus and the upper jaws of Tyrannosaurus, with a higher amount of shear along the mesio-distal axis occurring in the mid-maxillary teeth. The dentary teeth of Tyrannosaurus, however, show a different stress distribution pattern, with a higher amount of shear occurring along the labio-lingual axis of the mid-dentary teeth. These differences in jaw mechanics suggest that the function of teeth in the lower jaw of Tyrannosaurus shifted a few positions to compensate different proportions in the dentary that cause the anterior dentary teeth to be aligned with the largest maxillary teeth in Tyrannosaurus. These results suggest that heterodonty in these groups is different and that tooth form and function are sensitive to jaw proportions.

Section 2 Summary—Functional Morphology and Ecology of Larval Forms

2018 ◽  
Keyword(s):  
Life History ◽  
Functional Morphology ◽  
Morphological Variation ◽  
Aquatic Environment ◽  
Molecular Variation ◽  
Form And Function ◽  
Life History Stages ◽  
Taxonomic Groups ◽  
And Function ◽  
Exogenous Nutrients

Larvae are intermediate life history stages between embryos and juvenile and/or reproductive stages, but this characteristic is about the only feature that unites the incredible diversity of larval forms. The majority of larval forms evolved in the sea and exhibit tremendous morphological, physiological, and molecular variation, many of which are potential adaptations to match form and function in the context of the aquatic environment. The three chapters in this section review how larvae from different taxonomic groups sort through and ingest exogenous nutrients and how environmental variation elicits morphological variation....

Vertebrate paleontology: new approaches and new insights

Paleobiology ◽  
1980 ◽  
Vol 6 (3) ◽  
pp. 250-270 ◽  
Author(s):  
James A. Hopson ◽  
Leonard B. Radinsky
Keyword(s):  
Fossil Record ◽  
Plate Tectonics ◽  
Distribution Patterns ◽  
Form And Function ◽  
Late Cambrian ◽  
New Information ◽  
Biological Interpretation ◽  
Evolution Of Mammals ◽  
Cenozoic Mammals ◽  
And Function

In the past fifteen years, the biological interpretation of vertebrate fossils has been markedly advanced by the application of experimental techniques in functional morphology, biomechanical and allometric modelling, more rigorously-derived empirical correlations between form and function in living species, and studies of modern community structure and of the taphonomic processes by which fossil assemblages are formed. Traditional paleontological methods of phylogenetic analysis are under attack by the advocates of cladistics; the resulting debate is leading to increased rigor in paleontological systematics. Paleobiogeographical studies of vertebrates has become an extremely active area of research due to the need to reanalyze past distribution patterns in the light of plate tectonics.New information has extended the fossil record of vertebrates back to the Late Cambrian, but little more is known about the nature of the earliest vertebrates or of the pre-vertebrate ancestors. Much has been learned of the fishes antecedent to tetrapods but little of the earliest tetrapods. The early reptiles are now well known, but the nature of their amphibian ancestors is uncertain. Restudy of Archaeopteryx has suggested a dinosaurian ancestry for birds. The origin and early evolution of mammals is the subject of extensive research as a result of greatly augmented recent collecting. The most active and innovative research is on the biology of dinosaurs, especially on their physiology. Among Cenozoic mammals, the fossil record of primates has been greatly expanded and knowledge of primate history, from the basal prosimians of the Paleocene to early man, is increasing rapidly.

scholarly journals Melding Modeling and Morphology: A Call for Collaboration to Address Difficult Questions about the Evolution of Form and Function

2020 ◽  
Vol 60 (5) ◽  
pp. 1188-1192
Author(s):  
Lindsay D Waldrop ◽  
Jonathan A Rader
Keyword(s):  
Functional Morphology ◽  
The Other ◽  
Form And Function ◽  
Interdisciplinary Collaborations ◽  
And Function

Synopsis The nascent field of evolutionary biomechanics seeks to understand how form begets function, and researchers have taken two tacks toward this goal: inferring form based on function (comparative biomechanics) or inferring function based on form (functional morphology). Each tack has strengths and weaknesses, which the other could improve. The symposium, “Melding modeling and morphology—integrating approaches to understand the evolution of form and function” sought to highlight research stitching together the two tacks. In this introduction to the symposium’s issue, we highlight these works, discuss the challenges of interdisciplinary collaborations, and suggest possible avenues available to create new collaborations to create a unifying framework for evolutionary biomechanics.

Constraints of ligament growth, form and function on evolution in the Arcoida (Mollusca: Bivalvia)

Paleobiology ◽  
1976 ◽  
Vol 2 (1) ◽  
pp. 64-83 ◽  
Author(s):  
R. D. K. Thomas
Keyword(s):  
Shell Growth ◽  
Growth Patterns ◽  
Fibrous Materials ◽  
Shell Size ◽  
Form And Function ◽  
Direct Measurements ◽  
Adductor Muscles ◽  
Environmental Adaptations ◽  
Modes Of Life ◽  
And Function

Growth processes and patterns set functional limits on the adaptive range of organisms that have evolved a particular “Bauplan.” The design of the elastic ligament has played a large part in determining the scope of the evolutionary radiation of the Arcoida. Tensional lamellar and compressional fibrous materials of this ligament, which appear to be similar in their elastic properties to those of other bivalves, are not segregated in positions where they could best perform their different mechanical functions. The growth of this unspecialized ligament exhibits strong positive allometry, with respect to shell size, in many fossil and living arcoids. A simple mechanical model shows that this allometry is essential if the strength of the ligament is to keep up with the weight of the animal, during ontogeny. Inherent disadvantages of the allometry include increasing dorsal breakage of the ligament itself, interference with the function of the hinge teeth and reduction of the closing moment exerted by the adductor muscles. Direct measurements of living arcoids show that allometric growth just maintains a linear relationship between ligament strength and animal volume. Major differences in ligament strength are related to shell growth patterns and substantially different environmental adaptations. Ligament strength is highly variable within individual populations; between populations, it is correlated with shell thickness and local environmental conditions. Most arcoids are adapted for shallow-burrowing or epifaunal modes of life in physically unstable environments, where they are frequently disturbed. The large, muscular foot enables these mobile animals to regain suitable living positions after such disturbances. The weak ligament has limited the potential specialization of the arcoids for either deeper burrowing or permanent epibyssal attachment, also requiring the retention of the foot in epifaunal forms. This ligament has made diverse adaptations possible, while preventing extreme specialization, except in isolated taxa. As such, it is largely responsible for the evolutionary reversals documented by Stanley (1972). This is konstrukionsmorphologie No. 46.

First Carboniferous thylacocephalan from Europe and its significance for the understanding of functional morphology of Concavicarididae Schram, 2014

Crustaceana ◽  
2018 ◽  
Vol 91 (3) ◽  
pp. 265-285 ◽  
Author(s):  
Štěpán Rak ◽  
Krzysztof Broda ◽  
Tomáš Kumpan
Keyword(s):  
New Species ◽  
Functional Morphology ◽  
Fossil Record ◽  
Free Swimming ◽  
Lower Carboniferous ◽  
Form And Function ◽  
Mode Of Life ◽  
Moravian Karst ◽  
And Function ◽  
Evolutionary Aspects

Thylacocephala Pinna, Arduini, Pesarini & Teruzzi 1982 are among the most enigmatic arthropods. Their fossil record is very patchy both geographically and stratigraphically. In this paper we describe the first thylacocephalan known from the Carboniferous (Mississippian) of Europe, Concavicaris viktoryni sp. nov. Until now Carboniferous representatives of Thylacocephala were know exclusively from the U.S.A. We discuss the stratigraphic and geological context of occurrence of this new species as well as form and function of the unique carapace micro- and macro-ornamentation. A shape and assumed function of the characteristic lirae on the C. viktoryni sp. nov. carapace present an important supporting argument for the supposed free-swimming or pelagic mode of life in thylacocephalans. Palaeobiogeographical and evolutionary aspects of surprisingly rich but local occurrence of thylacocephalans in the Lower Carboniferous of the Moravian karst are discussed. Possible sympatric evolution from its predecessor Concavicaris incola is also pointed out.

Sign in / Sign up

Export Citation Format

Share Document