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The primary goal of this study was to document the gross morphological and histological structure and histomorphometrical measurements of the intestines and digestive glands of ostrich (Struthio camelus) in relation to advancing age and sex. A total of 40 clinically healthy ostriches of either sex [(20 males, 20 females comprising of two age groups, viz, immature (1 month to 2.4 years) and adult (2.5 to 10 years)] of equal size were selected. Immediately after collection, morphological studies were carried out on all organs. Histological and histometrical studies were conducted on paraffin-embedded tissue sections with Image J® analysis software. Macroscopic parameters of the intestines, liver and pancreas invariably showed a rapid increase (P

Extant cassowaries (Casuarius) are unique flightless birds found in the tropics of Indo-Australia. They have garnered substantial attention from anatomists with focus centered on the bony makeup and function of their conspicuous cranial casques, located dorsally above the orbits and neurocranium. The osteological patterning of the casque has been formally described previously; however, there are differing interpretations between authors. These variable descriptions suggest that an anatomical understanding of casque anatomy and its constituent elements may be enhanced by developmental studies aimed at further elucidating this bizarre structure. In the present study, we clarify casque osteology of the southern cassowary (C. casuarius) by detailing casque anatomy across an extensive growth series for the first time. We used micro-computed tomography (μCT) imaging to visualize embryonic development and post-hatching ontogeny through adulthood. We also sampled closely related emus (Dromaius novaehollandiae) and ostriches (Struthio camelus) to provide valuable comparative context. We found that southern cassowary casques are comprised of three paired (i.e., nasals, lacrimals, frontals) and two unpaired elements (i.e., mesethmoid, median casque element). Although lacrimals have rarely been considered as casque elements, the contribution to the casque structure was evident in μCT images. The median casque element has often been cited as a portion of the mesethmoid. However, through comparisons between immature C. casuarius and D. novaehollandiae, we document the median casque element as a distinct unit from the mesethmoid.

The present study describes an almost complete cervical region of the fossil ostrich Struthio karatheodoris from the Turolian locality of Kerassia (Euboea, Greece). The material comes from two dist...

Pseudosuchians, archosaurian reptiles more closely related to crocodylians than to birds, exhibited high morphological diversity during the Triassic with numerous examples of morphological convergence described between Triassic pseudosuchians and post-Triassic dinosaurs. One example is the shuvosaurid Effigia okeeffeae which exhibits an "ostrich-like" bauplan comprising a gracile skeleton with edentulous jaws and large orbits, similar to ornithomimid dinosaurs and extant palaeognaths. This bauplan is regarded as an adaptation for herbivory, but this hypothesis assumes morphological convergence confers functional convergence, and has received little explicit testing. Here, we restore the skull morphology of Effigia, perform myological reconstructions, and apply finite element analysis to quantitatively investigate skull function. We also perform finite element analysis on the crania of the ornithomimid dinosaur Ornithomimus edmontonicus, the extant palaeognath Struthio camelus and the extant pseudosuchian Alligator mississippiensis to assess the degree of functional convergence with a taxon that exhibit "ostrich-like" bauplans and its closest extant relatives. We find that Effigia possesses a mosaic of mechanically strong and weak features, including a weak mandible that likely restricted feeding to the anterior portion of the jaws. We find limited functional convergence with Ornithomimus and Struthio and limited evidence of phylogenetic constraints with extant pseudosuchians. We infer that Effigia was a specialist herbivore that likely fed on softer plant material, a niche unique among the study taxa and potentially among contemporaneous Triassic herbivores. This study increases the known functional diversity of pseudosuchians and highlights that superficial morphological similarity between unrelated taxa does not always imply functional and ecological convergence.

A one-year old female ostrich (Struthio camelus) was presented for surgical excision with the history of growth near left hock joint (ankle) and progressively increasing in size. The tumorous mass was surgically excised after sedation and local infiltrative anesthesia. Histopathological examination of the mass revealed a large number of fibrocytes and fibroblasts arranged in an irregular manner accompanied with high degree of neovascularisation. Few areas also showed infiltration of inflammatory cells, degenerative fibroblast cells, high mitotic figures and extensive local invasion to surrounding soft tissues. These features were indicative of clear malignancy and condition was diagnosed as a case of fibrosarcoma.

In this study, the ultrastructural development of germ cells in the ostrich embryo was analysed. The nuclear organisation and morphological characteristics of cytoplasm in the developing germ cells, on embryonic days 20, 26, and 36 and the day of hatching (5 samples from each stage) was analysed using transmission electron microscopy (TEM). Germ cells located in the cortex of left ovaries were identified by their large size and centrally located nucleus, with a conspicuous nucleolus. In these cells, the cytoplasm contained an abundance of mitochondria and free ribosomes. The structure of Balbiani body, a villous-like elevation in wide intercellular space and desmosome junction between two adjacent germ cells was also studied. The germ cells during embryonic development showed structural differences in both the nucleus and cytoplasm.

Birds and crocodiles show radically different patterns of brain development, and it is of interest to compare these to determine the pattern of brain growth expected in dinosaurs. Here we provide atlases of 3D brain (endocast) reconstructions for Alligator mississippiensis (alligator) and Struthio camelus (ostrich) through ontogeny, prepared as digital restorations from CT scans of stained head and dry skull specimens. Our morphometric analysis confirms that ostrich brains do not change significantly in shape during postnatal growth, whereas alligator brains unfold from a cramped bird-like shape in the hatchling to an elongate, straight structure in the adult. We confirm that birds exhibit paedomorphic dinosaur endocranial traits such as retaining an enlarged and compact brain shape in the adult, whereas crocodiles show peramorphic traits where the brain elongates with growth as the skull elongates. These atlases of ontogenetic stages of modern bird and crocodilian endocrania provide a basis for comparison of non-avian dinosaur endocasts and consideration of the divergence of the "avian" and "crocodilian" modes of brain development and heterochronic change on phylogenies.

The avian lung is highly specialized and is both functionally and morphologically distinct 30 from that of their closest extant relatives, the crocodilians. It is highly partitioned, with a 31 unidirectionally ventilated and immobilized gas-exchanging lung, and functionally decoupled, 32 compliant, poorly vascularized ventilatory air-sacs. To understand the evolutionary history of 33 the archosaurian respiratory system, it is essential to determine which anatomical 34 characteristics are shared between birds and crocodilians and the role these shared traits play 35 in their respective respiratory biology. To begin to address this larger question, we examined 36 the anatomy of the lung and bronchial tree of ten American alligators (Alligator 37 mississippiensis) and eleven ostriches (Struthio camelus) across an ontogenetic series using 38 traditional and micro-computed tomography (µCT), three-dimensional (3D) digital models, and 39 morphometry. Intraspecific variation and left to right asymmetry were present in certain 40 aspects of the bronchial tree of both taxa but was particularly evident in the cardiac (medial) 41 region of the lungs of alligators and the caudal aspect of the bronchial tree in both species. The 42 cross-sectional area of the primary bronchus at the level of the major secondary airways and 43 cross-sectional area of ostia scaled either isometrically or negatively allometrically in alligators 44 and isometrically or positively allometrically in ostriches with respect to body mass. Of fifteen 45 lung metrics, five were significantly different between the alligator and ostrich, suggesting that 46 these aspects of the lung are more interspecifically plastic in archosaurs. One metric, the 47 distances between the carina and each of the major secondary airways, had minimal 48 intraspecific or ontogenetic variation in both alligators and ostriches, and thus may be a 49 conserved trait in both taxa. In contrast to previous descriptions, the 3D digital models and CT 50 scan data demonstrate that the pulmonary diverticula pneumatize the axial skeleton of the 51 ostrich directly from the gas-exchanging pulmonary tissues instead of the air sacs. Global and 52 specific comparisons between the bronchial topography of the alligator and ostrich reveal 53 multiple possible homologies, suggesting that certain structural aspects of the bronchial tree 54 are likely conserved across Archosauria, and may have been present in the ancestral 55 archosaurian lung.

Diclofenac has been responsible for the deaths of millions of vultures on the Asian subcontinent. While the pathology of toxicity is well described, the mechanism of toxicity remains elusive. However, it was postulated that toxicity could be related to the unique avian renal vascular structure known as the renal portal valve and that that diclofenac altered valve functionality with subsequent renal ischaemia. While plausible, the valva renalis portalis has only been described in a small number of other bird species such as the chicken (Gallus domesticus), the domestic duck (Anas platyrhynchos domesticus) and ostrich (Struthio camelus) but not a raptor. The aim of this study was to evaluate the renal anatomy and related vasculature of the Cape griffon vulture (Gyps coprotheres) (CGV), a species sensitive to the toxic effects of diclofenac, using gross anatomy, histology and vascular casting. The vasculature of the vulture was found to be almost identical to that of the domestic chicken with the valva renalis portalis present in the v. iliaca externa between the v. renalis renalis cranialis and the v. renalis caudalus. The valve was ring-shaped with finger-like processes and histologically was composed of smooth muscle. The valve was also well vascularized and was associated with a nerve plexus. Based on the findings of this study, the proposed mechanism of toxicity is anatomically possible.

The ostrich (Struthio camelus, Linnaeus 1758) is the largest bird in the world. It is of great economic importance in Africa and is found across several countries. With developments in breeding systems, morphological studies that facilitate the application of the knowledge are necessary, considering the species has unique anatomical features. The objective of the present study was to describe the major tributaries of the hepatic vein in the species. Ten viscera of adult individuals of both sexes, which were injected with Neoprene latex through the hepatic vein, were used to visualize their tributaries. After the vascular repletion, the tissues were fixed and conserved in 10% formaldehyde aqueous solution. The hepatic carrier system was dissected and photo-documented. The left hepatic vein receives blood from the proventricle and gastric ventricle, while the right hepatic vein is responsible for the drainage of blood into the following organs: spleen, through the proventriculosplenic vein; pancreas, through the pancreaticoduodenal vein; jejunum, through the jejunum trunk; and the colon, which forms the cranial mesenteric vein. Resumo O avestruz (Struthio camelus, Linnaeus 1758) é a maior ave do mundo, com uma importância comercial acentuada na África e expandindo-se para diversos países. Assim, com o desenvolvimento dos sistemas de criação, tornam-se necessários estudos morfológicos que subsidiem as áreas aplicadas, pois a espécie apresenta características anatômicas próprias. O objetivo deste estudo foi a descrição dos principais afluentes da veia porta-hepática nesta espécie. Para a realização do presente trabalho, foram utilizadas dez vísceras de animais adultos, de ambos os sexos, que foram injetados com Neoprene látex por meio da veia porta-hepática para evidenciar os seus afluentes. Após a repleção vascular, os animais foram fixados e conservados em solução aquosa de formaldeído a 10%. O sistema porta-hepático foi dissecado e fotodocumentado. Observou-se que a veia porta-hepática esquerda recebe sangue da região do proventrículo e ventrículo gástrico. A veia porta-hepática direita é a responsável pela drenagem do sangue nos seguintes órgãos: baço, por meio da veia proventriculoesplênica, pâncreas, pela veia pancreaticoduonais, jejuno, por meio do tronco jejunal, e o cólon, que forma a veia mesentérica cranial.

A specialized region of the bill tip characterized by a complex arrangement of mechanoreceptors and referred to as a bill tip organ, has been identified in numerous avians. A bill tip organ was initially inferred in kiwi species by the presence of numerous, bony pits in the rostrum of the bill, and later confirmed histologically. This study enumerates and compares the number and distribution of pits present in the bill tip in the ostrich and emu. The heads from 10 ostrich and 5 emu were prepared for osteological examination. The pattern and total number of pits was similar between the two species. However, the ostrich had significantly more pits in the regions underlying the Culmen and Gonys, whereas the emu displayed significantly more pits in the dorsal part of the mandibular rostrum. The relatively even distribution of pits in the inner and outer surfaces of both the mandibular and maxillary rostra suggest that the bill tip of the ostrich and emu are equally sensitive externally and intra-orally, as opposed to probing birds, where the major concentration of pits is located on the outer surfaces of the bill tips. The presence of pits in the bill tips of extant paleaognaths may be of relevance in interpreting the pits in the rostra of extinct therapod dinosaurs. The presence of bony pits in a region which is also well supplied with sensory nerves is highly suggestive of a bill tip organ in the ostrich and emu and which needs to be confirmed histologically. Anat Rec, 300:1705-1715, 2017. © 2017 Wiley Periodicals, Inc.

In rapidly growing animals there are numerous selective pressures and developmental constraints underpinning the ontogenetic development of muscle-tendon morphology and mechanical properties. Muscle force generating capacity, tendon stiffness, elastic energy storage capacity and efficiency were calculated from muscle and tendon morphological parameters and in-vitro tendon mechanical properties, obtained from a growth series of ostrich cadavers. Ontogenetic scaling relationships were established using reduced major axis regression analysis. Ostrich pelvic limb muscle mass and cross-sectional area broadly scaled with positive allometry, indicating maintained or relatively greater capacity for maximum isometric force generation in bigger animals. The length of distal limb tendons was found to scale with positive allometry in several tendons associated with antigravity support and elastic energy storage during locomotion. Distal limb tendon stiffness scaled with negative allometry with respect to body mass, with tendons being relatively more compliant in larger birds. Tendon material properties also appeared to be size-dependent, suggesting the relative increased compliance of tendons in larger ostriches is due in part to compensatory distortions in tendon material properties during maturation and development, not simply from ontogenetic changes in tendon geometry. Our results suggest that the previously reported increase in locomotor economy through ontogeny in the ostrich is likely due to greater potential for elastic energy storage with increasing body size. In fact, the rate of this increase may be somewhat greater than the conservative predictions of previous studies thus illustrating the biological importance of elastic tendon structures in adult ostriches.

Ostrich (Struthio camelus) is a species belonging to the Struthionidae family of Struthioniformes order that does not have the flying ability among birds. The aim of this study was to make a subgross investigation on anatomical structures of middle ear in ostrich and to determine the morphometry of the columella. In the present study, 4 adult ostrich heads were used in the study. Tympanic cavity and the formations inside are removed from the skull by protecting the cranial roof. Subgross examinations of tympanic cavity, columella and other anatomic structures were then performed, and morphometric measurements of columella and some anatomical structures were performed using a digital calliper.It was determined that tympanic cavity, surrounded by ear capsule (os oticum), had a conical shape and was covered with mucosa that was tightly adjacent to the periosteum. Tympanic membrane, columella and osteochondral structures, ligaments, a branch of external ophthalmic artery and the presence of chorda tympani were detected in tympanic cavity. It was observed that columella was placed diagonally in tympanic cavity. The vestibular (proximal) end having a circular shape was found to have a large basis and annular ligament which ended up with thickened, small columns. Finally, we demonstrated anatomy and morphometric values of middle ear in ostrich. The anatomy and formations of the middle ear are clearly shown. It can be asserted that anatomical formations in the middle ear of an ostrich are similar to other birds.

The hyoid bone of the ostrich was divided into two parts; basihyoid and horns. The basihyoid consisted of three components; paraglossal, basihayle and urohyale. The paraglossal was unpaired,lay within the tongue parenchyma.On the other hand; the basihaylewas flat and octagonalcontinuing caudally by urohyale, which was stick like, compressed laterally.It reached at the first six trachea ringslevel. On the other hand, the horns included two pairs: ceratobranchiale and epibranchiale. The ceratobranchiale horn was ossified, concave and the longest one. It had bulges extremities for articulates with the basihayle proximally and epibranchiale horn distally, while the epibranchiale horn was cartilagenous structure, shorter than the ceratobranchiale and its end was tapered. The hyoid bone of the ostrich was firmly attached to the tongue, larynx,trachea and the cervical muscculature tissue and all underlying structures by the connective tissue.

This study, facilitated by the use of immunohistochemistry, indicated the presence of taste buds in Dromaius novaehollandiae but not in Struthio camelus. Seen at the light microscope level, the taste buds consisted of follicular cells and receptor cells. The follicular cells were located at the periphery of the taste bud, essentially encapsulating the receptor cells. Two morphologically distinct receptor cells were identified. Immunohistochemical labelling for neurofilament identified gustatory nerves within the taste bud. The distribution of taste buds in D. novaehollandiae matched strategic locations in the oropharynx along which food could be sampled, according to the feeding method described for these birds. Future feeding studies would be necessary in D. novaehollandiae to determine the importance of taste discrimination in their diet. This study represents the first confirmed report of a sense of taste in any ratite species.

The objective of this study was to investigate the morphological features of the proventriculus of African ostrich (Struthio camelus). The location, appearance, and histological characteristics of the proventriculus were observed on postnatal day 90. The entire proventriculus had the appearance of a distensible sac; and exhibited a large number of glands. Under light microscope, the proventriculus wall was composed of mucosa, submucosa, muscular layer and adventitia. The mucosa was further divided into the lamina epithelialis, lamina propria, and muscularis mucosae. The submucosa was relatively thick and contained compound tubular glands having oxynticopeptic cells, mucous cells, and endocrine cells. These features of the proventriculus are possibly related to the dietary habits of the African ostrich, and they imply that this specie has a strong ability to digest and absorb food.

Flexor tendons function as energy storage and shock absorption structures in the tarsometatarso-phalangeal joint (TMTPJ) of ostrich feet during high-speed and heavy-load locomotion. In this study, mechanisms underlying the energy storage and shock absorption of three flexor tendons of the third toe were studied using histology and scanning electron microscopy (SEM). Macroscopic and microscopic structures of the flexor tendons in different positions of TMTPJ were analyzed. Histological slices showed collagen fiber bundles of all flexor tendons in the middle TMTPJ were arranged in a linear-type, but in the proximal and distal TMTPJ, a wavy-type arrangement was found in the tendon of the M. flexor digitorum longus and tendon of the M. flexor perforans et perforatus digiti III, while no regular-type was found in the tendon of the M. flexor perforatus digiti III. SEM showed that the collagen fiber bundles of flexor tendons were arranged in a hierarchically staggered way (horizontally linear-type and vertically linear-type). Linear-type and wavy-type both existed in the proximal TMTPJ for the collagen fiber bundles of the tendon of the M. flexor perforatus digiti III, but only the linear-type was found in the distal TMTPJ. A number of fibrils were distributed among the collagen fiber bundles, which were likely effective in connection, force transmission and other functions. The morphology and arrangement of collagen fiber bundles were closely related to the tendon functions. We present interpretations of the biological functions in different positions and types of the tendons in the TMTPJ of the ostrich feet.

The distribution of Herbst corpuscles in the oropharynx of the ostrich and emu has recently been documented. However, although the morphology of these mechanoreceptors is well known in neognathous birds, little structural information is available on the Herbst corpuscles of ratites. Tissue sections from those regions of the oropharynx known to possess a high concentration of Herbst corpuscles were sampled from ostrich and emu heads collected after slaughter and prepared for light and transmission electron microscopy. Intra-oral Herbst corpuscles in the ostrich and emu displayed the same basic components (capsule, outer zone, inner core and axon) described in neognathous birds. However, some important differences were observed, notably, the presence of myofibroblasts in the capsule, sensory cilia in cells of the outer layers, a relatively larger, less organized outer zone and narrower inner core, and variations in the shape of the axon. The previously unreported presence of myofibroblasts in the capsule possibly indicates its ability to contract, thus altering the tension of the capsule, which in turn has implications for the conduction of vibrational stimuli. The sensory cilia in the myofibroblasts of the capsule bordering the outer zone, and in the fibroblasts of the outer zone itself, may play a regulatory role in controlling the contraction of the capsule. Such a function has not previously been reported for Herbst corpuscles in any species of bird. Anat Rec, 298:783–796, 2015. © 2014 Wiley Periodicals, Inc.

Herbst corpuscles are widely distributed throughout the oropharynx of the ostrich and emu in contrast to the general situation in birds. Knowledge of the comparative distribution of Herbst corpuscles in the oropharynx of these two commercially important ratite species may assist in a better understanding of their feeding habits. Tissue sections representing all parts of the oropharynx of five ostrich and five emu heads collected after slaughter were prepared for light microscopy, the Herbst corpuscles counted, and the relative percentage of corpuscles calculated for defined anatomical regions. Herbst corpuscles were more widespread in the oropharynx of the emu (where they were additionally found in the tongue and laryngeal mound) than in the ostrich but were absent from the pharyngeal folds in both species. The results further indicated that Herbst corpuscles were strategically located to aid in the handling and transport of food. In this context, the high concentration of Herbst corpuscles in the prominent median palatine and ventral ridges in the ostrich denote these structures as sensory organs, namely the palatal and interramal organs. The presence of these sensory organs, coupled with the higher relative percentage of Herbst corpuscles located on the rostral oropharyngeal floor, indicate that the part of the oropharynx caudal to the mandibular and maxillary rostra forms an important sensory region in the ostrich. Additionally, species-specific concentrations of Herbst corpuscles within the oropharynx were identified which appear to assist in the accurate positioning of the tongue and laryngeal mound for cleaning the choana (internal nares) after swallowing.

Normal haematopoiesis, cellular components and M/E ratio in the bone marrow of the male adult ostriches (Struthio camelus)were studied. Bone marrow samples were collected from the proximal tibiotarsus bone of 10 healthy adult ostriches. The bone marrow smears were stained using the Giemsa stain. The results indicated that the development and formation of blood cells in the bone marrow of partridge were similar to other birds. The morphology of the cells was similar to chickens, ducks, quail, and black-head gull. The mean myeloid/erythroid (M/E) ratio was 1.02, the mean erythroid percentage was 47.38%, the mean myeloid percentage was 48.15%, the mean thrombocytic percentage was 3.52% and the mean percentage of all other cells percentage was 0.99%

Background The ostrich Struthio camelus reaches the highest speeds of any extant biped, and has been an extraordinary subject for studies of soft-tissue anatomy and dynamics of locomotion. An elongate tarsometatarsus in adult ostriches contributes to their speed. The internal osteology of the tarsometatarsus, and its mechanical response to forces of running, are potentially revealing about ostrich foot function. Methods/Principal Findings Computed tomography (CT) reveals anatomy and bone densities in tarsometatarsi of an adult and a young juvenile ostrich. A finite element (FE) model for the adult was constructed with properties of compact and cancellous bone where these respective tissues predominate in the original specimen. The model was subjected to a quasi-static analysis under the midstance ground reaction and muscular forces of a fast run. Anatomy–Metatarsals are divided proximally and distally and unify around a single internal cavity in most adult tarsometatarsus shafts, but the juvenile retains an internal three-part division of metatarsals throughout the element. The juvenile has a sparsely ossified hypotarsus for insertion of the m. fibularis longus, as part of a proximally separate third metatarsal. Bone is denser in all regions of the adult tarsometatarsus, with cancellous bone concentrated at proximal and distal articulations, and highly dense compact bone throughout the shaft. Biomechanics–FE simulations show stress and strain are much greater at midshaft than at force applications, suggesting that shaft bending is the most important stressor of the tarsometatarsus. Contraction of digital flexors, inducing a posterior force at the TMT distal condyles, likely reduces buildup of tensile stresses in the bone by inducing compression at these locations, and counteracts bending loads. Safety factors are high for von Mises stress, consistent with faster running speeds known for ostriches. Conclusions/Significance High safety factors suggest that bone densities and anatomy of the ostrich tarsometatarsus confer strength for selectively critical activities, such as fleeing and kicking predators. Anatomical results and FE modeling of the ostrich tarsometatarsus are a useful baseline for testing the structure’s capabilities and constraints for locomotion, through ontogeny and the full step cycle. With this foundation, future analyses can incorporate behaviorally realistic strain rates and distal joint forces, experimental validation, and proximal elements of the ostrich hind limb.

SUMMARY Recent studies have presented range of motion (ROM) data in degrees for dinosaur forelimb joints, usually via physical manipulation of one individual. Using these data, researchers have inferred limb orientations, postures, gaits, ecological functions and even phylogenetic trends within clades. However, important areas of concern remain unaddressed; for example, how does ROM at a forelimb joint change after soft tissues are lost in archosaurs? And are fossil ROM methodologies amenable to reproducibility and statistical analysis? Here, we investigated these questions using the extant phylogenetic bracket of dinosaurs. Repeated measures of elbow joint ROM from Struthio camelus and Alligator mississippiensis forelimbs were statistically analyzed as they were sequentially dissected through five levels of tissue removal treatment. Our data indicate that there are no statistically significant differences in repeated measures of ROM between observers who use the same techniques. Extrinsic soft tissues, such as integument, muscles and ligaments were found to impede ROM at the elbow joint. Intrinsic soft tissues, such as articular cartilage, may increase ROM. The hypothesis that the articular surfaces of the bones within the elbow joints of archosaurs provide a general approximation of mobility is supported. Final ROMs were less than the initial ROMs in both taxa, which suggests that prior reports of elbow joint ROMs in degrees for nonavian dinosaurs may represent conservative estimates. We conclude that if observer bias and other variables are controlled for, ROM studies of fossil archosaur limbs can obtain useful degree data for inferring joint mobility in vivo.

This study was conducted to determine the presence of enterobacteria in the eggs of ostriches reared on a farm with a history of reproductive failure. Ninety samples from twenty eggs were submitted to bacteriological tests. The results showed Enterobacteria growth in 100% of the eggs. The microorganisms isolated were Hafnia alvei in 50% (10/20), Serratia spp. in 20% (4/20), Escherichia coli in 15% (3/20), and Citrobacter freundii in 15% (3/20). All eggs presented poor eggshell quality, which favored enterobacteria contamination. Hafnia alvei was present only in the internal egg structures (albumen and yolk sac), suggesting the possibility of vertical infection.

The erection mechanism of the penis in most vertebrates is blood vascular. A major evolutionary transition occurred in birds, where the erection mechanism changed from blood vascular to lymphatic. Within birds, however, the erection mechanism of the ratite penis has remained unknown. Early work suggested that the erection mechanism in ostrich Struthio camelus was blood vascular while no description existed for the emu Dromaius novaehollandiae or the rhea Rhea americana. Because the penis in all other described birds has a lymphatic erection mechanism, clarifying that the erection mechanism of ratites is of great importance to understanding one of the major evolutionary transitions of penis morphology within amniotes. Here, we show that the erection mechanism of ratites is lymphatic, confirming that the evolutionary transition to lymphatic erection occurred in the last common ancestor of Aves.

The ostrich foot has four digital pads, two on the 3rd digit, one on the 4th digit and one at metatarsophalangeal joint. Although these footpads are essential for long distance locomotion of the ostrich, no published data is available on the structure of these footpads. Therefore, the aim of this study is to examine the histo-morphological structure of these footpads in an attempt to highlight their structural functional adaptation for long distance motion. Morphologically, the ventral surface of each footpad is covered by numerous papillae which are varied in direction, length and thickness. In histological examination, the epidermis of the footpad consists of outer stratum corneum and inner stratum germinativum (which is subdivided into basal, intermediate and transitional layers). The stratum corneum has several layers of flattened horney cells. The nuclei of the basal cells have several mitotic figures. The cytoplasm of the stratum germinativum cells has multiple lipid droplets and multigranular bodies (in transitional cells only). Using scanning electron microscope, the collagen fibers in the mid and deep dermis of the footpad run parallel and connect to each other by very thin fibrils which are branched, crossed with each other in an oblique direction. Such arrangement of these collagen fibers and thin fibrils and presence of digital cushion are likely to be responsible for absorption of concussion and hence acceleration of the ostrich movement. We have concluded that ostrich footpads have unique modified structures which are adapted for long distance movement and protection of the underlying soft tissues.

The spleen structurally and functionally belongs to the hematopoietic organs and is also an important component of the reticuloendothelial system, which is known to play a major role in host defense. The histological structure of the spleen was investigated in the ostrich, a non-flying bird, the kestrel, a raptor, and the osprey, a fish-eating bird of prey (fish eagle). For this purpose, Mallory's modified triple stain, methyl green-pyronin and silver stain were used. Germinal centers were not present in the spleen of the osprey. In the spleen of the kestrel, penicillar arterioles and the surrounding lymphoid tissue were markedly dense. Compared to the other two birds, the red and white pulps were clearly distinguishable in the spleen of the ostrich.

In nonavian dinosaur long bones, the once-living chondroepiphysis (joint surface) overlay a now-fossilized calcified cartilage zone. Although the shape of this zone is used to infer nonavian dinosaur locomotion, it remains unclear how much it reflects chondroepiphysis shape. We tested the hypothesis that calcified cartilage shape reflects the overlying chondroepiphysis in extant archosaurs. Long bones with intact epiphyses from American alligators (Alligator mississippiensis), helmeted guinea fowl (Numida meleagris), and juvenile ostriches (Struthio camelus) were measured and digitized for geometric morphometric (GM) analyses before and after chondroepiphysis removal. Removal of the chondroepiphysis resulted in significant element truncation in all examined taxa, but the amount of truncation decreased with increasing size. GM analyses revealed that Alligator show significant differences between chondroepiphysis shape and the calcified cartilage zone in the humerus, but display nonsignificant differences in femora of large individuals. In Numida, GM analysis shows significant shape differences in juvenile humeri, but humeri of adults and the femora of all guinea fowl show no significant shape difference. The juvenile Struthio sample showed significant differences in both long bones, which diminish with increasing size, a pattern confirmed with magnetic resonance imaging scans in an adult. Our data suggest that differences in extant archosaur long bone shape are greater in elements not utilized in locomotion and related stress-inducing activities. Based on our data, we propose tentative ranges of error for nonavian dinosaur long bone dimensional measurements. We also predict that calcified cartilage shape in adult, stress-bearing nonavian dinosaur long bones grossly reflects chondroepiphysis shape.

In this study, retinal whole-mount specimens were prepared and stained with 0.1% cresyl violet for the ganglion cell study in the ostrich (Struthio camelus). The total number, distribution, and size of these cells were determined in different retinal regions. The mean total number of ganglion cells (three retinas) was 1,435,052 with an average density of 652 cells/mm(2). The temporo-nasal area of the retina with high cell density were identified with the peak of 7525 cells/mm(2) in the central area. The size of most ganglion cells ranged from 113-403 microm(2), with smaller cells predominating along the temporo-nasal streak above the optic disc and larger cells comprising more of the peripheral regions. The average thickness of the retina was 196 microm. The central area was the thickest area (268.6 microm), whereas the peripheral area was the thinnest area. Thus, the specialization of ganglion cell densities, their sizes and the thickness of the retina support the notion that the conduction of visual information towards the brain from all regions of the retina is not uniform, and suggests that the temporo-nasal streak is the fine quality area for vision in ostriches.

In birds, the ability to void urine separate from faeces is unique to ostriches. To further explore this characteristic, the anatomy of the terminal rectum and cloaca of the Ostrich Struthio camelus was studied in four ostriches by gross anatomical dissection and light microscopy. The terminal rectum had an unusual tunica muscularis externa (TME) and was clearly demarcated from the caudal part of the rectum proper by a semilunar fold, an abrupt thickening of the gut wall and an increase in the calibre of the gut. The cloaca had a distinct rectocoprodeal fold at the terminal rectum–cloaca junction with a well-formed sphincter muscle. The cloaca had a proximal coprodeum, a middle urodeum and a caudal proctodeum. The mucosa of the cloaca was folded and lined by simple columnar epithelium except in the urodeum and the floor and ventral walls of the proctodeum. The coprodeal wall had a thick circular muscle layer; however, the other parts of the cloaca mainly had longitudinally/obliquely directed fibres in the TME. This muscle arrangement could contribute to the dynamics of the terminal rectum that allow for separate defecation and micturition. We also propose a schema for this phenomenon that for birds is unique to ostriches. OSTRICH 2009, 80(3): 185–191

In order to characterize lesions associated with Codiostomum struthionis in ostriches, 10 caeca were examined on both macro- and microscopic levels. Parasites were found in the distal third of the caecum and characterized as C. struthionis. Thickened mucosa was identified macroscopically where parasites were observed in high concentrations. Nodular areas were also observed in the distal third of the infected caeca, as well as hemorrhagic areas abutting small ulcers surrounded by edema. These findings were not observed in healthy controls. The concentration of C. struthionis found in infected animals was directly correlated with the severity of lesions observed in each caecum. These results allowed us to infer that C. struthionis is responsible for lesions in ostrich caeca.

Commercial breeding of ostriches in the northern parts of Europe is still discussed controversially in particular in winter. Here we measured the body temperature of 12 ostriches of two different ages during 12 weeks in winter using temperature loggers implanted subcutaneously and in the abdominal cavity. The mean peritoneal temperature ranged between 37.4 and 38.5 °C in the younger subjects and between 37.2 and 38.1 °C in the older subjects. Climatic conditions significantly affected the body temperature but in comparison with the variations between and within subjects these effects were low. There was no evidence that the young ostriches were not able to adapt towards the climatic conditions prevalent during our study.

Palaeognaths constitute one of the most basal lineages of extant birds, and are also one of the most morphologically diverse avian orders. Their skeletal development is relatively unknown, in spite of their important phylogenetic position. Here, we compare the development of the postcranial skeleton in the emu (Dromaius novaehollandiae), ostrich (Struthio camelus), greater rhea (Rhea americana) and elegant crested-tinamou (Eudromia elegans), focusing on ossification. All of these taxa are characterized by element loss in the appendicular skeleton, but there are several developmental mechanisms through which this loss occurs, including failure to chondrify, failure to ossify and fusion of cartilages prior to ossification. Further evidence is presented here to support a reduction in size of skeletal elements resulting in a delay in the timing of ossification. This study provides an important first look at the timing and sequence of postcranial ossification in palaeognathous birds, and discusses the influence of changes in the pattern of skeletal development on morphological evolution.

Ratites and tinamous are a morphologically diverse group of flightless and weakly flighted birds. As one of the most basal clades of extant birds, they are frequently used as an outgroup for studies discussing character evolution within other avian orders. Their skeletal development is not well known in spite of their important phylogenetic position, and studies have historically been plagued with small sample sizes and limited anatomical and temporal scope. Here, I describe the ossification of the skull in the emu (Dromaius novaehollandiae), ostrich (Struthio camelus), greater rhea (Rhea americana), and elegant crested-tinamou (Eudromia elegans). Skeletal development is remarkably consistent within palaeognaths, in spite of large differences in absolute size and incubation period. Adult morphology appears to play a role in interordinal differences in the sequence and timing of ossification of certain bones. Neither the timing of cranial ossification events relative to stage nor the sequence of ossification events provides any evidence in support of a paedomorphic origin of the palaeognathous palate. This study provides an important first look at the timing and sequence of skull development in palaeognathous birds, providing data that can be compared to better-studied avian systems in order to polarize ontogenetic characters. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 156, 184–200.

The tongue of birds fills the oral cavity and has a beak-like shape. Morphological studies of birds reveal a correlation between the structure of the tongue and the mechanism of food intake and the type of food. However, several studies have shown morphological differences among the tongues of bird species. The aim of this study was to analyze ostrich tongue morphology and ultrastructural features using scanning electron microscopy. Tongues from 12 adult ostriches were examined. Six tongues were sectioned sagittally into lateral and middle portions, fixed in 10% formaldehyde solution, and examined under light microscopy. The other six samples were sectioned longitudinally, and the dorsal and ventral surfaces were separated, immersion-fixed in modified Karnovsky solution, and examined under scanning electron microscopy. The tongue surface of the ostrich was smooth, without lingual papillae, and covered by stratified non-keratinized epithelium. In the submucosal layer, mucous salivary glands were surrounded by connective-tissue capsules, with septa dividing the glands into lobes. Numerous salivary gland ducts of different sizes and connective-tissue laminae dividing each opening could be clearly seen in scanning electron microscope images. The ventral surface had fewer openings than the dorsal surface. In samples treated with NaOH, connective-tissue papillae from the dorsal region were oriented posteriorly.

Two neurohypophysial hormones have been isolated from an avian species, the ostrich, Struthio camelus. Both have been characterized by amino acid analysis and sequence determination. The data obtained suggest that the oxytocin-like hormone is [Ile8-oxytocin] (mesotocin) and the vasopressin-like hormone is [Ile3-vasopressin] (vasotocin). Bioactivity measurements based on urinary conductivity showed vasotocin to be about five times as active as mesotocin.

The epididymal duct unit, comprising the ductus conjugens, ductus epididymidis and ductus deferens, was studied histologically, ultrastructurally and immunohistochemically in five sexually mature and active birds. The main morphological features of the pre-dominant non-ciliated (type III) cell of the epithelial lining of this duct unit include, but are not limited to, a moderately abundant smooth or sparsely granulated endoplasmic reticulum, electron-dense secretory granules and numerous mitochondria in the supranuclear zone of the cytoplasm. A single, large heterogeneous lipid droplet, of unknown function, was characteristically situated immediately proximal to the nucleus. The epithelium is obviously secretory and specifically, of the merocrine, and not apocrine, type of secretion. The epithelium of the epididymal duct unit was only focally and weakly to moderately immunopositive to both actin MF and desmin IF, while the duct unit was immunonegative to cytokeratin and vimentin intermediate filaments. The peritubular muscular layer was moderately to strongly positive to both actin and desmin, and negative to cytokeratins and vimentin.

The testicular capsule and peritubular boundary tissue of the emu and ostrich, as typical representatives of ratite birds, were studied in sexually mature and active birds. The testicular capsule was much thicker (578.1+/-73.4 microm for the free surface of the ostrich testis, and 176.2+/-57.5 microm for the emu) than those of members of the Galloanserae. The cellular composition of both testicular capsule and peritubular tissue was similar generally to that of members of the previously studied Galloanserae and of mammals. The tunica albuginea of the testicular capsule mainly comprised smooth-muscle-like or myoid cells mostly running in one direction and occurring in one main mass. Unlike the Galloanserae, the tunica albuginea contained more collagen fibres than smooth muscle cells, especially in the ostrich. Peritubular tissue was similarly composed of smooth-muscle-like cells distributed in several layers. Actin microfilaments and desmin and vimentin intermediate filaments were variably immunoexpressed in these two tissue types in both birds, with a clear dichotomy in the peritubular tissue. Thus, taken together with studies of some members of the Galloanserae, avian testes clearly contain a morphological mechanism that is represented partly by the smooth muscle cells of the testicular capsule and peritubular tissue for transporting the testicular fluid, which is usually copious in birds, and its cellular content from the testis into the excurrent duct system; this mechanism is similar to that found in mammals.

Introduction and objetives The columella of birds, often cited in the literature, has yet to be adequately described. We aim to give an account of this transmission element, describing its anchoring systems and detailing the muscle associated to it. Material and method We performed microscopic dissection and obtained images of ostrich specimens ( Struthio camelus ), chosen because it is the bird with the largest head. Results We describe the columella: the osseous tripod formed on its external section (extracolumella), the conic shape of its inner section (stapedial), and links to the tympanic membrane and the oval window. We describe its anchoring system: posterior ligament and annular ligament. We conclude by describing the characteristics of the columella muscle, its insertions and the fibrous vein surrounding it. Conclusions The avian middle ear is a valid model for understanding the mechanical characteristics of the human ear repaired with total ossicular replacement prosthesis, ie replacement of the ossicular chain by a single element. We highlight an apparent contradiction: the existing muscle is inserted into the columella in an area close to the tympanic membrane rather than adjacent to the oval window.

We developed a three-dimensional, biomechanical computer model of the 36 major pelvic limb muscle groups in an ostrich (Struthio camelus) to investigate muscle function in this, the largest of extant birds and model organism for many studies of locomotor mechanics, body size, anatomy and evolution. Combined with experimental data, we use this model to test two main hypotheses. We first query whether ostriches use limb orientations (joint angles) that optimize the moment-generating capacities of their muscles during walking or running. Next, we test whether ostriches use limb orientations at mid-stance that keep their extensor muscles near maximal, and flexor muscles near minimal, moment arms. Our two hypotheses relate to the control priorities that a large bipedal animal might evolve under biomechanical constraints to achieve more effective static weight support. We find that ostriches do not use limb orientations to optimize the moment-generating capacities or moment arms of their muscles. We infer that dynamic properties of muscles or tendons might be better candidates for locomotor optimization. Regardless, general principles explaining why species choose particular joint orientations during locomotion are lacking, raising the question of whether such general principles exist or if clades evolve different patterns (e.g. weighting of muscle force-length or force-velocity properties in selecting postures). This leaves theoretical studies of muscle moment arms estimated for extinct animals at an impasse until studies of extant taxa answer these questions. Finally, we compare our model’s results against those of two prior studies of ostrich limb muscle moment arms, finding general agreement for many muscles. Some flexor and extensor muscles exhibit self-stabilization patterns (posture-dependent switches between flexor/extensor action) that ostriches may use to coordinate their locomotion. However, some conspicuous areas of disagreement in our results illustrate some cautionary principles. Importantly, tendon-travel empirical measurements of muscle moment arms must be carefully designed to preserve 3D muscle geometry lest their accuracy suffer relative to that of anatomically realistic models. The dearth of accurate experimental measurements of 3D moment arms of muscles in birds leaves uncertainty regarding the relative accuracy of different modelling or experimental datasets such as in ostriches. Our model, however, provides a comprehensive set of 3D estimates of muscle actions in ostriches for the first time, emphasizing that avian limb mechanics are highly three-dimensional and complex, and how no muscles act purely in the sagittal plane. A comparative synthesis of experiments and models such as ours could provide powerful synthesis into how anatomy, mechanics and control interact during locomotion and how these interactions evolve. Such a framework could remove obstacles impeding the analysis of muscle function in extinct taxa.

Dissections of 12 formalin-fixed ostriches were performed to give anatomical descriptions of the muscles and tendons of the pelvic, femoral, tibiotarsal, tarsometatarsal and digital regions. In the pelvic limb of the ostrich, 36 muscles can be determined. The ostrich lacks those muscles to the first and second toes (with exception of the M. flexor hallucis longus), which can be found in birds with four toes. The Mm. iliotrochantericus medius, plantaris, extensor proprius digiti IV and adductor digiti IV, which are present in other birds, are also absent, whereas the Mm. pectineus and femorotibialis accessorius additionally occur in the ostrich. The Pars supramedialis is a tendineous part of the M. gastrocnemius, on which the Mm. flexor cruris lateralis and flexor cruris medialis insert by means of a fascial sheet. The caudal part of the M. iliofibularis terminates within the caudal aspect of the superficial fascia cruris. The caudal heads of the Mm. flexor perforatus digiti III and flexor perforatus digiti IV as well as the M. flexor hallucis longus have a common origin on the Fossa poplitea of the femur. The lateral head of the M. flexor perforatus digiti IV and the femoral head of the M. flexor perforans et perforatus digiti III originate on the tendon of origin of the Caput laterale of the M. flexor perforatus digiti III. Furthermore, the last named tendon fuses with the tendon of insertion of the M. ambiens. The M. extensor proprius digiti III originates on a plate-like fascial sheet part of the dorsal joint capsule of the intertarsal joint.

Summary The aim of this study was to investigate the topographical, anatomical and histological characteristics of syrinx in five ostriches. It was observed that the syrinx in the ostrich was tracheobronchial type and was composed of three different cartilage groups, namely tympanum, cartilagines (cartt.) tracheosyringeales and cartt. bronchosyringeales. Tympanum and cartt. tracheosyringeales were formed from three and four cartilage rings, respectively, while cartt. bronchosyringeales was formed from three C-shaped cartilage rings. The pessulus did not contain any ossified or cartilaginous tissues and was made up of a double folded mucous membrane extending dorsoventrally from median walls of bronchus primarius into the cavum syringis.

Simple testicular cysts are rare in mammals and of unknown aetiology, but dietary conditions have been implicated in this phenomenon in poultry. This study characterises the structural features of simple intratesticular cysts in the ostrich. Seven testes from a total of 15 sexually mature ostriches slaughtered during the breeding season were used. The testes contained multifocal, fluid-filled, unilocular cysts which were lined by a simple squamous or low cuboidal epithelium and surrounded by a thick layer of fibrous connective tissue. The cysts developed within seminiferous tubules and displayed morphological features similar to those reported in man and domestic poultry. The testis parenchyma revealed several foci composed of intermingled normal seminiferous tubules and variably sized intratesticular cysts. The atrophic tubules lay within a mass of hyperplastic, fibroblastic intertubular connective tissue in the proximity of large cysts and their formation appeared to result from hydrostatic pressure exerted by cysts. Morphological evidence supports a continuous process of cyst formation in the affected testis and a concomitant progressive loss of atrophic seminiferous tubules. A pathogenetic scenario of cyst formation and the effect of simple cysts on testicular histology has been proposed. Although the course of this phenomenon remains unknown, its impact on the fertility of this economically important bird deserves closer scrutiny.

1. The presence of sperm storage tubules in the cranial, middle and caudal regions of the vagina in the immature ostrich was studied. In addition, progesterone and oestrogen receptor immunoreactivity in these regions was investigated. 2. Sperm storage tubules were observed only in birds with active ovaries. Progesterone receptor immunoreactivity was more intense in birds with active ovaries, whilst immunostaining for the oestrogen receptor was absent in birds with both active and inactive ovaries. 3. These results suggest that steroid hormones produced by the active ovary mediate the activation of the progesterone receptor.

The possibility was investigated that translocation of juvenile ostriches from concrete-paved to sand-floored pens and mixing of batches of ostriches after such translocation constitute a stress strong enough to evoke changes in the ratio of heterophils to lymphocytes. Blood smears were obtained from 15 ostriches out of a group of 25 birds 4 and 2 days before and then 2 and 4 days after translocation. The heterophil to lymphocyte ratio changed from 0.27 and 0.37 on days 4 and 2, respectively, before mixing and translocation to 0.53 and 0.84 on days 2 and 4, respectively, after translocation. Mixing and translocating juvenile ostriches appears to constitute stress. This information is important for the on-farm management of juvenile ostriches to enhance their welfare and productivity.

Avian tuberculosis rarely affects ratites compared to other bird species and is typically caused by Mycobacterium avium species. This study describes the pathological and microbiological findings in three adult ostriches with mycobacteriosis, in one of which Mycobacterium bovis was isolated from the lesions. Post mortem examinations on ostriches from two different zoological collections in Ireland revealed multifocal caseous granulomas affecting the spleen and liver in all cases, with additional involvement of intestines in two cases. In one case, granulomas were present within the pharynx, at the thoracic inlet and multifocally on the pleural surface. Acid-fast bacilli were observed in all lesions. Mycobacterium sp. of the M. avium complex was isolated from the intestinal lesions in the two cases with intestinal involvement, and M. bovis sp. oligotype SB0140 was cultured from the liver of the third ostrich. This represents the first reported case of M. bovis infection in an ostrich. Avian tuberculosis due to M. bovis is rare and to date has been reported in only parrots and experimentally inoculated birds. Mycobacterium bovis needs to be considered as a possible cause of tuberculosis in ostriches because the lesions are similar to those observed with M. avium complex infection.

Yolk sac retention or the failure to absorb yolk is a common problem in recently hatched ostrich chicks (Struthio camelus) and is one of the major causes of mortality in the first 2 weeks after hatching. In a study of 80 yolk sacs from dead-in-shell (DIS) eggs (n = 24) and ostrich chicks up to 3 weeks after hatching (n = 56), several aspects were considered. A predictive curve for normal growth and yolk absorption was calculated, a histologic study of “normal” and “retained yolk” sacs was conducted, and a microbiological evaluation of yolk sacs and the chicks was performed. Findings were discussed in comparison to comparable data for poultry and in relation to possible causes of yolk sac retention. At necropsy, the diagnosis of retained yolk sac was made 13 times. No differences were observed by histopathologic examination between chicks with yolk sac retention and normal chicks. When the predictive curve was compared with direct observations at necropsy, the direct method had a sensitivity and s...

The optical structure of the eyes of ostriches (Struthio camelus; Struthionidae; Struthioniformes) was determined by the construction of a schematic eye model for paraxial optics. The eye is large (axial length = 38 mm) and of globose shape with an anterior focal length (posterior nodal distance) of 21.8 mm. The optical design of the eye is such that the lens and cornea contribute equally to its total optical power. Interspecific comparison shows that optically the ostrich eye is a larger scaled version of the eyes of common starlings (Sturnus vulgaris) and an owl (Strix aluco).