Abstract Functional analysis of the limb bones erethizontid Steiromys duplicatus , one most abundant Miocene porcupines from Patagonia, provides evidence to infer their locomotor behavior. Remains giant Neosteiromys pattoni (Late Northeast Argentina) are also analyzed. Osteological and myological features extant were evaluated used as a model interpret functional significance species' limbs. Several in erethizontids compatible with ability climb: low humeral tuberosities indicate mobile...

Abstract The greater rhea ( Rhea americana ) is the largest bird in South America. It flightless and cursorial, with a precocial postnatal development. This study aims to describe morphological changes pelvic girdle of , focusing on ontogenetic scaling gross anatomy provide insight into potential relationship between structure function cursorial birds. pelves 18 specimens representing four stages, were studied. Gross anatomical observations staining methods used identify bone cartilage,...

Abstract In Strigiformes, which comprise the Tytonidae and Strigidae families, hindlimbs play a crucial role in prey capture. Yet, their bone proportions remain understudied despite established link between avian hindlimb skeletal morphology ecological traits. We examined of femur, tibiotarsus, tarsometatarsus 18 owl species, investigating associations with preferences, body mass, phylogenetic signals. Our results indicate that owls generally have short femur tarsometatarsus, relatively long...

Abstract Psittaciformes are a very diverse group of non‐passerine birds, with advanced cognitive abilities and highly developed locomotor feeding behaviours. Using computed tomography three‐dimensional (3D) visualization software, the endocasts 14 extant Neotropical parrots were reconstructed, aim analysing, comparing exploring morphology brain within clade. A 3D geomorphometric analysis was performed, encephalization quotient (EQ) calculated. Brain character states traced onto tree in order...

Background Andalgalornis steulleti from the upper Miocene–lower Pliocene (≈6 million years ago) of Argentina is a medium-sized patagornithine phorusrhacid. It was member predominantly South American radiation 'terror birds' (Phorusrhacidae) that were apex predators throughout much Cenozoic. A previous biomechanical study suggests skull would be prepared to make sudden movements in sagittal plane subdue prey. Methodology/Principal Findings We analyze flexion patterns neck based on vertebrae...

With 13 figures Summary The Greater Rhea is the largest cursorial Ratitae bird native to South America. Due its increasing importance in farming and therefore sustainable use of this species, a comprehensive knowledge their anatomy essential. goal study was provide an anatomical description hindlimb muscles americana . Six adult birds both sexes were macroscopically studied analysing origin insertion thigh shank muscles. showed highest number muscles, whereas lowest number; feature minimizes...

We describe the hindlimb myology of Milvago chimango. This member Falconidae: Polyborinae is a generalist and opportunist that can jump run down prey on ground, unlike Falconinae hunt birds in flight kill them by striking with its talons. Due to differences locomotion habits between subfamilies, we hypothesized their myology. Gross dissections showed M. chimango concordant described other falconids, except for following differences: m. flexor cruris medialis has one belly longitudinal...

ABSTRACT We studied the hindlimb myology of monk parakeet ( Myiopsitta monachus ). Like all parrots, it has zygodactyl feet enabling perching, climbing, hanging, moving easily among trees, and handling food. Muscles were described weighed, physiological cross‐sectional area (PCSA) four flexors one extensor was calculated. In comparison to other muscles, M. tibialis cranialis fibularis brevis show increased development high PCSA values, therefore, large potential force production. Also, a...

Abstract The greater rhea ( R hea americana ) is the largest flightless bird of S outh A merica and has a cursorial locomotion style. objective this study was to explore how leg configuration species changes from juveniles adult, possible implications these for locomotor style bird. In regard, it interesting presence allometries during growth (ontogenetic allometry), because may provide information about morpho‐functional aspects. Growth femur, tibiotarsus tarsometatarsus were studied in...

The greater rhea (Rhea americana) is the largest South American bird. It a cursorial, flightless species with long powerful legs and reduced forelimbs. goal of this study was to explore how hindlimb muscles scale body mass during postnatal growth analyze whether specialized locomotion affects muscle masses. 19 were weighed in 21 specimens ranging from 1-month-old individuals adults. Seventeen scaled positive allometry respect mass, whereas two isometrically. predominance allometric results...

We examined the external anatomy of endocast Greater Rhea (<i>Rhea americana</i>, Palaeognathae), during 3 main stages its postnatal life, and compared it with information available on other palaeognathous birds. Series scans spiral computed tomographies were obtained from skulls different ages (chick, juvenile adult) <i>R. americana</i>; digital 3-dimensional reconstruction was performed brain volumes calculated models obtained. Qualitative assessment...

ABSTRACT The neurocranial fragment from the Late Miocene (Huayquerian SALMA, 9,0 to 6,8 Ma) of Estancia La Pastosa new locality, Puerto Madryn Formation, Patagonia, Argentina, is described. This first available fossil skull Accipitridae in South America. Features as elongated-triangular shape cranial roof, vast separation between processus postorbitalis and both fossae temporalis, narrow acuminate outline fossa temporalis allow assign Vieilloit, 1816. well-preserved cavum cranii allowed...

Abstract The article presents the taxonomic study carried out on Rheidae (Palaeognathae: Ratitae) faunal remains recovered in open‐air archaeological site Boyo Paso 2 dated at approximately 1500–750 years BP (Sierras of Córdoba, Argentina). is focused an adult proximal tarsometatarsus, a juvenile distal tarsometatarsus and 453 eggshell remains. specimens were identified to its most specific level exploring describing diagnostic keys species/genera identification modern reference collections....

Abstract The hindlimb of the Polyborinae has always been characterized as long when it was compared with other diurnal raptors; however, no empirical work done to support such a traditional well‐known fact. objective this is analyze femur, tibiotarsus and tarsometatarsus group corroborate whether assumption significant statistical support. proportions these bones were analyzed one‐way Kruskal–Wallis test Dunn's post hoc comparisons. allometric relationships between body mass or total length...

This work studied the skeletal and muscular syringeal anatomy of Greater Rhea (Rhea americana) throughout postnatal ontogeny, by using muscle staining differential coloring cartilage bone techniques. Anatomical syrinx dissections on four adults (one female three males) eight unsexed chicks, were made. The type was tracheobronchial it entirely cartilaginous in chicks adult but showed a partially osseous pessulus male adults. A pair intrinsic muscles found extrinsic represented...

Abstract Caracaras, falcons and forest falcons, which are representative of the three subfamilies family Falconidae, have different flight behaviour. Since, during flight, tail works in coordination with wings, muscles could be indicative type The aim this work was to describe detail little‐known Falconidae explore their possible association behaviour, by using muscle mass as an indicator. To end, 18 specimens representing were dissected, weighed percentage body calculated. differences...

Abstract The aim of this study was to describe the histological structure skin greater rhea ( Rhea americana ), a ratite bird native South America. Skin samples were taken from three regions trunk (alar, dorsal and pelvic) in 14 specimens which ages ranged 7 days adulthood. Serial sections obtained subjected different staining procedures (haematoxylin eosin, orcein, Masson's trichrome Gomori), morphometric analysis carried out on stained slides. In general, both epidermis dermis showed...

Rhea pampeana Moreno and Mercerat 1891 is an extinct species of Rheidae (Aves, Palaeognathae) from the Pleistocene Buenos Aires province, Argentina. This taxon has been subject different confusing changes its taxonomic status, adequate description still lacking. study re-examines materials assigned to with objective evaluate their status as a distinct fossil species. The poor preservation plus certain osteological features tibiotarsus tarsometatarsus allowed reassign these living americana.

We present new specimens of a teratorn (Aves, Teratornithidae) from the Chasicoan (early late Miocene) southwestern Buenos Aires Province, Argentina. The consist an incomplete left ulna without its proximal end and two fragments radius. is very similar to, but larger than, Vultur, size relative slenderness distal shaft excludes it Cathartidae diagnostic Teratornithidae. Its length to Teratornis merriami, so wingspan would have been around 4 m. Coming sediments Barrancas Member Arroyo Chasicó...

Abstract The objective of this study was to the morphological pattern bone maturation hindlimb bones Rhea americana and find out how it can affect morphology after a taphonomic process. Juvenile specimens ( n = 10) ranging from one month old eight months were studied. For comparison, adults juveniles museum 4 6, respectively) In fresh bones, ossification centres identified in proximal distal epiphyses tibiotarsi epiphysis tarsometatarsi, whereas region femora tarsometatarsi showed abundance...

Barn Owls (Tytonidae) are nocturnal raptors with the largest geographical distribution among Strigiformes. Several osteological, morphometrical, and biomechanical studies of this species were performed by previous authors. Nevertheless, myology forelimb tail is virtually unknown. This study first detailed myological on wing American Owl (Tyto furcata). A total 11 specimens dissected their morphology muscle masses described. Although T. furcata has pattern present in other Strigiformes, some...