scholarly journals Visualization of a Juvenile Australopithecus afarensis Specimen: Implications for Functional Foot Anatomy

2019 ◽  
Vol 43 (2) ◽  
Author(s):  
Eleanor Milman ◽  
John Daugherty ◽  
Zeresenay Alemseged ◽  
Kevin Brennan ◽  
Leah Lebowicz
Keyword(s):  
Human Evolution ◽  
Fossil Record ◽  
Functional Anatomy ◽  
Morphological Characteristics ◽  
Bipedal Locomotion ◽  
Australopithecus Afarensis ◽  
Foot Anatomy

Since it was named in 1978, analyses of Australopithecus afarensis have culminated in several dominant theories on how humans acquired many of their unique adaptations. Because bipedal locomotion is one of the earliest characteristics of human functional anatomy to appear in the fossil record, its associated anatomy in early hominins has significant implications for human evolution (Stern, 2000). The skeleton and overall morphological characteristics of the foot in Australopithecus afarensis provide important clues about the origins of upright bipedal locomotion.

scholarly journals Understanding the foot’s functional anatomy in physiological and pathological conditions: the calcaneopedal unit concept

2019 ◽  
Vol 13 (2) ◽  
pp. 134-146 ◽  
Author(s):  
I. Ghanem ◽  
A. Massaad ◽  
A. Assi ◽  
M. Rizkallah ◽  
A. J. Bizdikian ◽  
...  
Keyword(s):  
Functional Anatomy ◽  
Sparse Data ◽  
Standing Position ◽  
Review Article ◽  
Foot Deformities ◽  
Pathological Conditions ◽  
Orthopaedic Literature ◽  
Foot Anatomy

Background A thorough review of the available orthopaedic literature shows significant controversies, inconsistencies and sparse data regarding the terminology used to describe foot deformities. This lack of consensus on terminology creates confusion in professional discussions of foot anatomy, pathoanatomy and treatment of deformities. The controversies apply to joint movements as well as static relationships between the bones. Description The calcaneopedal unit (CPU) is a specific anatomical and physiological entity, represented by the entire foot excepted the talus. The calcaneus, midfoot and forefoot are solidly bound by three strong ligaments that create a unit that articulates with the talus. The movement of the CPU is complex, as it rotates under the talus, around the axis of Henke that coincides with the talo-calcaneal ligament of Farabeuf. This calcaneopedal unit is deformable. It is compared with a twisted plate, able to adapt to many physiological situations in standing position, in order to acheive a plantigrade position. Moreover, the calcaneopedal unit and the talo-tibiofibular complex are interdependent; rotation of the latter produces morphologic modifications inside the former and vice versa. Purpose This paper is a review article of this concept and of its physiopathological applications.

scholarly journals Constructional and functional anatomy of Ediacaran rangeomorphs

2020 ◽  
pp. 1-12
Author(s):  
Nicholas J Butterfield
Keyword(s):  
Fluid Dynamics ◽  
Gas Exchange ◽  
Organic Carbon ◽  
Fossil Record ◽  
White Sea ◽  
Functional Anatomy ◽  
Food Delivery ◽  
The White Sea ◽  
Total Group ◽  
Taphonomic Analysis

Abstract Ediacaran rangeomorphs were the first substantially macroscopic organisms to appear in the fossil record, but their underlying biology remains problematic. Although demonstrably heterotrophic, their current interpretation as osmotrophic consumers of dissolved organic carbon (DOC) is incompatible with the inertial (high Re) and advective (high Pe) fluid dynamics accompanying macroscopic length scales. The key to resolving rangeomorph feeding and physiology lies in their underlying construction. Taphonomic analysis of three-dimensionally preserved Charnia from the White Sea identifies the presence of large, originally water-filled compartments that served both as a hydrostatic exoskeleton and semi-isolated digestion chambers capable of processing recalcitrant substrates, most likely in conjunction with a resident microbiome. At the same time, the hydrodynamically exposed outer surface of macroscopic rangeomorphs would have dramatically enhanced both gas exchange and food delivery. A bag-like epithelium filled with transiently circulated seawater offers an exceptionally efficient means of constructing a simple, DOC-consuming, multicellular heterotroph. Such a body plan is broadly comparable to that of anthozoan cnidarians, minus such derived features as muscle, tentacles and a centralized mouth. Along with other early bag-like fossils, rangeomorphs can be reliably identified as total-group eumetazoans, potentially colonial stem-group cnidarians.

scholarly journals Debris-carrying camouflage among diverse lineages of Cretaceous insects

2016 ◽  
Vol 2 (6) ◽  
pp. e1501918 ◽  
Author(s):  
Bo Wang ◽  
Fangyuan Xia ◽  
Michael S. Engel ◽  
Vincent Perrichot ◽  
Gongle Shi ◽  
...  
Keyword(s):  
Fossil Record ◽  
Morphological Characteristics ◽  
Early Evolution ◽  
Behavioral Repertoire ◽  
Wood Fibers ◽  
Morphological Adaptations ◽  
Evolutionary Success ◽  
High Degree ◽  
Insect Assemblage ◽  
Insight Into

Insects have evolved diverse methods of camouflage that have played an important role in their evolutionary success. Debris-carrying, a behavior of actively harvesting and carrying exogenous materials, is among the most fascinating and complex behaviors because it requires not only an ability to recognize, collect, and carry materials but also evolutionary adaptations in related morphological characteristics. However, the fossil record of such behavior is extremely scarce, and only a single Mesozoic example from Spanish amber has been recorded; therefore, little is known about the early evolution of this complicated behavior and its underlying anatomy. We report a diverse insect assemblage of exceptionally preserved debris carriers from Cretaceous Burmese, French, and Lebanese ambers, including the earliest known chrysopoid larvae (green lacewings), myrmeleontoid larvae (split-footed lacewings and owlflies), and reduviids (assassin bugs). These ancient insects used a variety of debris material, including insect exoskeletons, sand grains, soil dust, leaf trichomes of gleicheniacean ferns, wood fibers, and other vegetal debris. They convergently evolved their debris-carrying behavior through multiple pathways, which expressed a high degree of evolutionary plasticity. We demonstrate that the behavioral repertoire, which is associated with considerable morphological adaptations, was already widespread among insects by at least the Mid-Cretaceous. Together with the previously known Spanish specimen, these fossils are the oldest direct evidence of camouflaging behavior in the fossil record. Our findings provide a novel insight into early evolution of camouflage in insects and ancient ecological associations among plants and insects.

scholarly journals A skull of a very large crane from the late Miocene of Southern Germany, with notes on the phylogenetic interrelationships of extant Gruinae

2020 ◽  
Vol 161 (4) ◽  
pp. 923-933
Author(s):  
Gerald Mayr ◽  
Thomas Lechner ◽  
Madelaine Böhme
Keyword(s):  
Late Miocene ◽  
Fossil Record ◽  
Morphological Characteristics ◽  
Southern Germany ◽  
Siberian Crane ◽  
Large Size ◽  
Early Late

Abstract We describe a partial skull of a very large crane from the early late Miocene (Tortonian) hominid locality Hammerschmiede in southern Germany, which is the oldest fossil record of the Gruinae (true cranes). The fossil exhibits an unusual preservation in that only the dorsal portions of the neurocranium and beak are preserved. Even though it is, therefore, very fragmentary, two morphological characteristics are striking and of paleobiological significance: its large size and the very long beak. The fossil is from a species the size of the largest extant cranes and represents the earliest record of a large-sized crane in Europe. Overall, the specimen resembles the skull of the extant, very long-beaked Siberian Crane, Leucogeranus leucogeranus, but its affinities within Gruinae cannot be determined owing to the incomplete preservation. Judging from its size, the fossil may possibly belong to the very large “Grus” pentelici, which stems from temporally and geographically proximate sites. The long beak of the Hammerschmiede crane conforms to an open freshwater paleohabitat, which prevailed at the locality.

‘Hurrah for the missing link!’: a history of apes, ancestors and a crucial piece of evidence

2011 ◽  
Vol 65 (1) ◽  
pp. 83-98 ◽  
Author(s):  
Peter C. Kjærgaard
Keyword(s):  
Nineteenth Century ◽  
Natural Selection ◽  
Human Evolution ◽  
Fossil Record ◽  
Animal Kingdom ◽  
Missing Link ◽  
Origin Of Species ◽  
Theory Of Evolution ◽  
History Of ◽  
Evolution By Natural Selection

In the nineteenth century the idea of a ‘missing link’ connecting humans with the rest of the animal kingdom was eagerly embraced by professional scientists and popularizers. After the publication of Charles Darwin's Origin of Species in 1859, many tied the idea and subsequent search for a crucial piece of evidence to Darwin and his formulation of the theory of evolution by natural selection. This article demonstrates that the expression was widely used and that the framework for discussions about human's relation to the apes and gaps in the fossil record were well in place and widely debated long before Origin of Species became the standard reference for discussing human evolution. In the second half of the century the missing link gradually became the ultimate prize in palaeoanthropology and grew into one of the most powerful, celebrated and criticized icons of human evolution.

scholarly journals Morpho-molecular diversity and evolutionary analyses suggest hidden life styles in Spumellaria (Radiolaria)

2020 ◽  
Author(s):  
Miguel M. Sandin ◽  
Tristan Biard ◽  
Sarah Romac ◽  
Luis O’Dogherty ◽  
Noritoshi Suzuki ◽  
...  
Keyword(s):  
Fossil Record ◽  
Morphological Characteristics ◽  
Radial Symmetry ◽  
Global Ocean ◽  
Marker Genes ◽  
Environmental Reconstruction ◽  
Taxonomic Rank ◽  
Middle Cambrian ◽  
Life Styles ◽  
Comprehensive Classification

AbstractSpumellaria (Radiolaria, Rhizaria) are holoplanktonic amoeboid protists, ubiquitous and abundant in the global ocean. Their silicified skeleton preserves very well in sediments displaying an excellent fossil record, from the early middle Cambrian (ca. 509-521 Ma), extremely valuable for paleo-environmental reconstruction studies. Spumellaria are tedious to maintain in laboratory conditions preventing an accurate perception of their extant diversity and ecology in today’s oceans, most of which being inferred from sediment records. This study represents an integrated and comprehensive classification of Spumellaria based on the combination of ribosomal taxonomic marker genes (rDNA) and morphological characteristics. In contrast to established taxonomic knowledge, we demonstrate that symmetry of the skeleton takes more importance than internal structures at high taxonomic rank classification. Such reconsideration allows gathering different morphologies with concentric structure and a spherical or radial symmetry believed to belong to other Radiolaria orders from the fossil record, as for some Entactinaria families. Results obtained in this study suggest the existence of new Spumellaria diversity at early diverging positions, in which a non-bearing skeleton organism lives within shelled ones. Using fossil calibrated molecular clock we estimated the origin of Spumellaria in the middle Cambrian (ca. 515 Ma), in agreement with the appearance of the first radiolarian representatives in the fossil record. The morpho-molecular and evolutionary framework established herein allows a direct connection between living specimens and fossil morphologies from the Cambrian, bringing both a standpoint for future molecular environmental surveys and a better understanding for paleo-environmental reconstruction studies.

scholarly journals Talar trochlear morphology may not be a good skeletal indicator of locomotor behavior in humans and great apes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuhei Nozaki ◽  
Motoharu Oishi ◽  
Naomichi Ogihara
Keyword(s):  
Geometric Morphometrics ◽  
Statistical Difference ◽  
Morphological Characteristics ◽  
Great Apes ◽  
Locomotor Behavior ◽  
Bipedal Locomotion ◽  
Apical Angle ◽  
Interspecific Differences ◽  
Fossil Hominins ◽  
Locomotor Behaviors

AbstractTo reconstruct locomotor behaviors of fossil hominins and understand the evolution of bipedal locomotion in the human lineage, it is important to clarify the functional morphology of the talar trochlea in humans and extant great apes. Therefore, the present study aimed to investigate the interspecific-differences of the talar trochlear morphology among humans, chimpanzees, gorillas, and orangutans by means of cone frustum approximation to calculate an apical angle and geometric morphometrics for detailed variability in the shape of the talar trochlea. The apical angles in gorillas and orangutans were significantly greater than those in humans and chimpanzees, but no statistical difference was observed between humans and chimpanzees, indicating that the apical angle did not necessarily correspond with the degree of arboreality in hominoids. The geometric morphometrics revealed clear interspecific differences in the trochlear morphology, but no clear association between the morphological characteristics of the trochlea and locomotor behavior was observed. The morphology of the trochlea may not be a distinct skeletal correlate of locomotor behavior, possibly because the morphology is determined not only by locomotor behavior, but also by other factors such as phylogeny and body size.

scholarly journals Bibliografía

1994 ◽  
Author(s):  
Juan Antonio Martos Romero ◽  
Eduardo Ripoll Perelló ◽  
José Pablo Paniagua Pérez ◽  
Silvia Margenat
Keyword(s):  
Human Evolution ◽  
Fossil Record ◽  
Cambridge University ◽  
Castilla Y Leon

RESEÑA 1 de : Haynes, Gary. Mammoths, Mastodonts, and Elephants. Biology, Behaviour, and the Fossil Record. USA : Cambridge University Press, 1991. RESEÑA 2 de : Romero Carnicero, Fernando; Sanz Mínguez, Carlos; Escudero Navarro, Zoa. Arqueología vaccea. Estudios sobre el mundo prerromano en la cuenca media del Duero. Valladolid : Junta de Castilla y León, Consejería de Cultura y Turismo, 1993. RESEÑA 3 de : Jones, Steve; Martin¡, Robert; Pilbeam, David. The Cambridge Encyclopedia of Human Evolution. USA : Cambridge University Press, 1992. RESEÑA 4 de : Cortijo Cerezo, María Luisa. La administración territorial de la Bética romana. Córdoba : Caja Provincial de Ahorros de Córdoba, 1993.

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