Abstract Psittaciform birds exhibit novelties in jaw bone structure and musculature that are associated with strong bite forces. These features include an ossified arcus suborbitalis the muscles ethmomandibularis pseudomasseter . We analyse of monk parakeet ( Myiopsitta monachus ) to enable future studies aimed at understanding craniofacial development, morphology, function evolution. estimate force based on muscle dissections, physiological cross‐sectional area skull biomechanical...

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...

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...

Knowledge about the embryonic stages of birds is important in answering many questions development and evolution. We give first description 41 embryological monk parakeet (Myiopsitta monachus) on basis external morphology comparison with chicken. also provide measurements some morphological characters (i.e. body mass, crown-rump, beak, forelimb, third toe lengths) perform comparisons other precocial altricial aim identifying heterochronous developmental features. The following differences...

SUMMARY The ossification sequence of Myiopsitta monachus was determined. has a similar to other altricial birds, with delayed skeletons compared precocial species. hindlimbs ossify before the forelimbs, condition that could be linked altriciality. To determine stability sequences across we selected species different groups Aves and used event‐pairing method character mapping on phylogeny. Our results show homogeneity in development birds supported by 56.77% states. Event‐pair cracking...

Abstract The main evolutionary milestone in the oviparity–viviparity transition is placentation. placenta an organ with great morphological diversity among eutherians. expression of different glycosidic residues (Gr) near‐term constitutes its glycotype. In this study, Gr was determined by lectin histochemistry early, midterm, and placentas plains viscacha ( Lagostomus maximus ), a caviomorph rodent highest poliovulatory rate embryonic resorption Besides, matrix each exchange trophoblast...

<title>Abstract</title> The avian evolutionary pathway led to morphological adaptive variations in their feet. Diverse foot types are accompanied by a complex muscle system, allowing birds adopt different primary lifestyles, and display various locomotor manipulative skills. We provide novel insights of functional significance on the architecture through Anatomical Network Analysis. Here we show that there is no link between more networks ability perform specialized skills or higher number...

Avian evolution led to morphological adaptive variations in feet. Diverse foot types are accompanied by a diverse muscle system, allowing birds adopt different primary lifestyles, and display various locomotor manipulative skills. We provide insights of evolutionary functional significance on the avian architecture through Anatomical Network Analysis, methodology focused connectivity patterns anatomical parts. Here, we show that: (1) parts largely conserved living already present ancestral...

Abstract We describe the morphology, histology, and histochemical characteristics of uropygial gland (UG) monk parakeet Myiopsitta monachus . The UG has a heart‐shape external appearance adenomers extensively branched with convoluted path, covered by stratified epithelium formed different cellular strata divided into three zones (based on epithelial height lumen width), cylindrical papilla an internal structure delicate type two excretory pores surrounded feather tuft. Histochemical...

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 The Hooded Grebe is an endangered and endemic species of Podicipediformes Argentina. Many aspects this bird's biology are still unknown including the uropygial gland. This first morphological histochemical description gland for in a comparative context. these birds had parallel arranged lobes with kidney‐like shape, conical papilla feather tuft sub‐terminal position. were composed tubular adenomers straight course that lead to secondary chambers. capsule connective tissue around...

Fil: Carril, Julieta. Universidad Nacional de la Plata. Facultad Ciencias Naturales y Museo. Catedra Histologia Embriologia Animal; Argentina. Consejo Investigaciones Cientificas Tecnicas; Argentina

Few investigators have examined in vivo bite-force of birds, likely due, at least part, to the difficulty accessing suitable force transducers. We describe a low-cost, easy-to-build, and portable transducer with goal encouraging ornithologists improve our knowledge bite forces birds. used commercial piezo-resistive sensor (Tekscan©) construct transducer, measure captive birds different beak morphologies, including following species: Greater Rhea (Rhea americana), Black-chested Buzzard-Eagle...

Abstract Foot-propelled diving comprises the primary locomotion-based feeding strategy for many birds, including families such as Phalacrocoracidae, Anhingidae, Podicipedidae, Gaviidae, and ducks within Anatidae. While morphology of specialized divers is well known, corresponding less known birds not but capable diving, coots (Rallidae, Fulica spp.). To compare osteology with other (non-diving) Rallidae, foot-propelled that are distantly related, we considered osteological characters,...