The large theropod dinosaur Tyrannosaurus rex underwent remarkable changes during its growth from <10 kg hatchlings to >6000 adults in <20 years. These raise fascinating questions about the morphological transformations involved, peak rates, and scaling of limb muscle sizes as well body's centre mass that could have influenced ontogenetic locomotion T. rex. Here we address these using three-dimensionally scanned computer models four large, well-preserved fossil specimens a putative juvenile...

The lineage leading to modern Crocodylia has undergone dramatic evolutionary changes in morphology, ecology and locomotion over the past 200+ Myr. These functional innovations may be explained part by morphological axial skeleton, which is an integral of vertebrate locomotor system. Our objective was estimate osteological range motion (RoM) intervertebral joint stiffness thoracic lumbar vertebrae with increasing aquatic adaptation crocodylomorphs. Using three-dimensional virtual models...

ABSTRACT For more than two centuries, the idea that forelimb and hindlimb are serially homologous structures has been accepted without serious question. This study presents first detailed analysis of evolution homologies all muscles in representatives each major tetrapod group proposes a unifying nomenclature for these muscles. These data compared with information obtained previously about tetrapods other gnathostomes order to address one most central enigmatic questions evolutionary...

Musculoskeletal models of the first vertebrate limbs reveal adaptations for propulsion, but not weight support.

Crocodiles and their kin (Crocodylidae) use asymmetrical (bounding galloping) gaits when moving rapidly. Despite being morphologically ecologically similar, it seems alligators (Alligatoridae) do not. To investigate a possible anatomical basis for this apparent major difference in locomotor capabilities, we measured relative masses internal architecture (fascicle lengths physiological cross-sectional areas) of muscles the pectoral pelvic limbs 40 individuals from six representative species...

Abstract Common chimps and bonobos are our closest living relatives but almost nothing is known about bonobo internal anatomy. We present the first phylogenetic analysis to include musculoskeletal data obtained from a recent dissection of bonobos. Notably, chimpanzees, in particular bonobos, provide remarkable case evolutionary stasis for since chimpanzee-human split c.8 Ma among &gt;120 head-neck (HN) forelimb (FL) muscles there were only four minor changes in chimpanzee clade, all...

Opossums are frequent subjects of developmental studies because marsupials share features not seen in placentals and Didelphimorpha is the sister-group other extant Marsupialia. But adult marsupial muscular system markedly different from that or it, like skeletal system, very similar? We provide, for first time, a brief description all head limb muscles Didelphis virginiana based on our dissections using unifying nomenclature by integrating data gathered long-term project development,...

Despite their semi-aquatic mode of life, modern crocodylians use a wide range terrestrial locomotor behaviours, including asymmetrical gaits otherwise only found in mammals. The key to these diverse abilities may lie the axial skeleton. Correlations between vertebral morphology and both intervertebral joint stiffness behaviour have been other animals, but mechanics not yet experimentally quantitatively tested. We measured passive thoracolumbar column Crocodylus niloticus order validate...

Network theory is increasingly being used to study morphological modularity and integration. Anatomical network analysis (AnNA) a framework for quantitatively characterizing the topological organization of anatomical structures providing an operational way compare structural integration modularity. Here we apply AnNA first time macroevolution musculoskeletal system head neck in primates their closest living relatives, paying special attention evolution associated with facial vocal...

ABSTRACT Tetrapod limbs are a key innovation implicated in the evolutionary success of clade. Although musculoskeletal evolution pectoral appendage across fins‐to‐limbs transition is fairly well documented, that pelvic much less so. The skeletal elements some tetrapodomorph fish and earliest tetrapods relatively smaller and/or qualitatively similar to those crown than appendage. However, comparative developmental works have suggested musculature tetrapod forelimb hindlimb was initially very...

Lobe-fins transformed into limbs during the Devonian period, facilitating water-to-land transition in tetrapods. We traced evolution of well-articulated skeletons across fins-to-limbs transition, using a network-based approach to quantify and compare topological features fins limbs. show that arrangement bones pectoral pelvic appendages evolved parallel occupying overlapping regions morphospace, following directional trend, decreasing their disparity over time. identify presence digits as...

Abstract Chameleon species have recently been adopted as models for evo‐devo and macroevolutionary processes. However, most anatomical developmental studies of chameleons focus on the skeleton, information about their soft tissues is scarce. Here, we provide a detailed morphological description based contrast enhanced micro‐CT scans dissections adult phenotype all forelimb hindlimb muscles Veiled ( Chamaeleo calyptratus ) compare these with those other lizards. We found appendicular muscle...

MOLNÁR, JÚLIATechnology and the widespread usage of internet have gradually changed design delivery several banking services.Internet mobile has become self-service channel, while new information technologies lowered barrier entering finance industry.These changes fueled entrance type banks financial institutions in sector.The common characteristics these entrants that they adopted an internet-only strategy rely on online networks to meet customers' transaction needs.The rise internet-based...

Abstract Previous accounts of the origin tetrapod limbs have postulated a relatively sudden change, after split between extant lobe-finned fish and tetrapods, from very simple fin phenotype with only two muscles to highly complex condition. The evolutionary changes that led muscular anatomy therefore remained unexplored. We performed dissections, histological sections, MRI scans closest living relatives tetrapods: coelacanths lungfish. Combined previous comparative, developmental...

Regionalization of the vertebral column can help animals adapt to different kinds locomotion, including arboreal locomotion. Although functional axial regionalization has been described in both chameleons and mammals, no morphological basis for this proposed. However, recent studies have presacral other extant squamates. To investigate possible chameleons, we took morphometric measurements from vertebrae 28 chameleon species representing all genera, fully ground-dwelling, performed...

Anatomical network analysis is a framework for quantitatively characterizing the topological organization of anatomical structures, thus providing way to compare structural integration and modularity among species. Here we apply this approach study macroevolution forelimb in primates, structure whose proportions functions vary widely within group. We analyzed musculoskeletal models 22 genera, including members all major extant primate groups three outgroup taxa, after an extensive literature...

Tetrapods evolved from within the lobe-finned fishes around 370 Ma. The evolution of limbs lobe-fins entailed a major reorganization skeletal and muscular anatomy appendages in early tetrapods. Concurrently, degree similarity between pectoral pelvic also evolved. Here, we compared extant (Latimeria Neoceratodus) anatomically plesiomorphic amphibians (Ambystoma, Salamandra) amniotes (Sphenodon) to trace reconstruct musculoskeletal changes that took place during fins-to-limbs transition. We...

Three-dimensional (3D) digital models of bone morphology are used frequently in paleontology and anthropology.Because fossils often fragmentary or distorted, it becomes necessary, for either aesthetic practical reasons, to create an idealized version skeletons.We propose a method building landmark-based geometric reconstructions fossil bones 3D graphics software using CT laser scan data as template.This does not require specialized artistic expertise.It allows control local mesh density,...

Studies of morphological integration and modularity, anatomical complexity in human evolution typically focus on skeletal tissues. Here we provide the first network analysis musculoskeletal anatomy both fore- hindlimbs two species chimpanzee humans. Contra long-accepted ideas, reveals that hindlimb displays a pattern opposite to forelimb: Pan big toe is seen as more independently mobile, but humans are actually ones have separate module exclusively related its movements. Different vs...

ABSTRACT Most anatomical studies of primates focus on skeletal tissues, but muscular anatomy can provide valuable information about phylogeny, functional specializations, and evolution. Herein, we present the first detailed description head, neck, pectoral, upper limb muscles fetal lemuriforms Lemur catta (Lemuridae) Propithecus coquereli (Indriidae). These two species belong to suborder Strepsirrhini, which is often presumed possess some plesiomorphic features within primates. We compare...

As a member of the most basal clade extant ray-finned fishes (actinopterygians) and one clades osteichthyans (bony + tetrapods), Polypterus can provide insights into ancestral anatomy both lobe-finned fishes, including those that gave rise to tetrapods. The pectoral fin has been well described but, surprisingly, neither bones nor muscles pelvic are known. We stained dissected senegalus delhezi offer detailed description its musculoskeletal anatomy. In addition previously adductor abductor...