Muscular Insertions Research Articles

The palaeopathology of the Ohalo 2 Upper Paleolithic human remains: A reassessment of its appendicular robusticity, humeral asymmetry, shoulder degenerations, and costal lesion

AbstractThe 23,000 BP Ohalo 2 human remains, from the Upper Paleolithic of south‐west Asia, have been described by Hershkovitz and colleagues as very robust but especially as pathological with respect to its level of humeral asymmetry and its large anteroinferior costal bony growth. Reassessment of its appendicular robusticity, in the context of western Eurasian and North African Upper Paleolithic human remains, indicates that the Ohalo 2 limb remains are unexceptional in terms of muscular enthesis development, diaphyseal cross‐sectional shape, and major long bone diaphyseal hypertrophy. If anything, the muscular insertions and the humeral diaphyseal robusticity are modest for an Upper Paleolithic human. Similarly, the level of humeral asymmetry, as well as humeral versus radial diaphyseal asymmetry, is well within Upper Paleolithic ranges of variation. None of these aspects require palaeopathological explanations. The minor osteoarthritic changes of the right clavicle and scapula are common and of little importance. However, the massive lower thoracic ossification of the caudal sternum, ribs 6 and 7 and the intervening costal cartilages, has implications beyond the differential diagnosis of Hershkovitz and colleagues. It indicates constraints on thoracic expansion and hence on elevated respiration; as such, it would have placed limitations on the activity levels of this Upper Paleolithic forager. Ohalo 2 therefore joins a growing sample of Upper Paleolithic humans with serious developmental or degenerative abnormalities.

Rapports entre la capsule antérieure de la gléno-humérale et le muscle sous-scapulaire : une étude anatomique et histologique

IntroductionThe purpose of this study was to delineate the anatomic relationship between the anterior articular capsule and the adjacent subscapularis by measuring the dimensions of the anterior articular capsule attachment and the subscapularis foot print on the humerus, as well as investigating the interface between the two structures. Materials and methodsThree shoulder specimens underwent histological analysis; for histological analysis, cross-sections through the subscapularis-capsule complex were harvested at the tendinous and muscular insertion sites. The dimensions of the anterior articular capsule attachment and the subscapularis footprint (including the tendinous and muscular insertions) were measured in thirteen cadaveric shoulder specimens. ResultsHistologically, the articular capsule has thin and loosely arranged collagen fibers with many interspersing fibroblast nuclei, whereas the outer layer of the articular capsule blends into a layer of more loosely spaced and less organized collagen fibers. This interface between the subscapularis and the underlying articular capsule is filled with more loosely spaced and less organized collagen fibers. The macroscopic evaluation showed that the minimum articular capsule width (4.2mm, SD 2.2mm) was located at its initiation 4.9mm (SD, 2.1mm) inferior to the superior margin of the subscapularis; the corresponding subscapularis footprint width measured 10.1mm (SD, 4.9mm). The maximum articular capsule width was 11.1mm (SD, 3.7mm) and was located 5mm distal to the inferior margin of the tendinous footprint. The maximum subscapularis footprint width was 15.8mm (SD, 2.9mm); the corresponding articular capsule attachment measured 5.2mm (SD, 1.8mm). ConclusionsOur results suggest that the anterior articular capsule attachment of the glenohumeral joint complements the footprint of the subscapular is and occupies a larger area of the lesser tubercle and metaphysis of the humerus than previously documented. The histological study confirms the presence of a demarcation between the subscapularis and articular capsule, specifically more significant at the region medial to the tendon insertion and at the muscular insertion of the subscapularis.

The relationship of the anterior articular capsule to the adjacent subscapularis: An anatomic and histological study

IntroductionThe purpose of this study was to delineate the anatomic relationship between the anterior articular capsule and the adjacent subscapularis by measuring the dimensions of the anterior articular capsule attachment and the subscapularis footprint on the humerus, as well as investigating the interface between the two structures. Materials and methodsThree shoulder specimens underwent histological analysis; for histological analysis, cross-sections through the subscapularis-capsule complex were harvested at the tendinous and muscular insertion sites. The dimensions of the anterior articular capsule attachment and the subscapularis footprint (including the tendinous and muscular insertions) were measured in thirteen cadaveric shoulder specimens. ResultsHistologically, the articular capsule has thin and loosely arranged collagen fibers with many interspersing fibroblast nuclei, whereas the outer layer of the articular capsule blends into a layer of more loosely spaced and less organized collagen fibers. This interface between the subscapularis and the underlying articular capsule is filled with more loosely spaced and less organized collagen fibers. The macroscopic evaluation showed that the minimum articular capsule width (4.2mm, SD 2.2mm) was located at its initiation 4.9mm (SD, 2.1mm) inferior to the superior margin of the subscapularis; the corresponding subscapularis footprint width measured 10.1mm (SD, 4.9mm). The maximum articular capsule width was11.1 mm (SD, 3.7mm) and was located 5mm distal to the inferior margin of the tendinous footprint. The maximum subscapularis footprint width was 15.8mm (SD, 2.9mm); the corresponding articular capsule attachment measured 5.2mm (SD, 1.8mm). ConclusionsOur results suggest that the anterior articular capsule attachment of the glenohumeral joint complements the footprint of the subscapularis and occupies a larger area of the lesser tubercle and metaphysis of the humerus than previously documented. The histological study confirms the presence of a demarcation between the subscapularis and articular capsule, specifically more significant at the region medial to the tendon insertion and at the muscular insertion of the subscapularis.

Bilateral Gastrocnemius Muscle Rupture in a Bovine

Background: Locomotor system diseases are quite common in the field practice in dairy cattle and represent an important cause of economics losses. The rupture of the gastrocnemius muscle has been reported in humans, cattle, horses, camels and llamas. It can be complete or partial. The rupture of muscle as well as sacral fractures are infrequent, and consequently not commonly reported in veterinary medicine. The aim of this work was to report a case of bilateral gastrocnemius rupture in a dairy cow related to a sacral (S2) fracture.Case: A 3-year-old Holstein cow with lameness and urinary incontinence was presented for clinical examination. After three days, clinical signs progressed to sternal recumbency and difficulty to keep normal posture. While standing, the cow’s tarsal joint showed a 90o degree angle with tibia, in a manner that the metatarsal bones were completely leant on the ground. Also, a marked enlargement in both gastrocnemius area were observed. The animal was in good body condition and alert,although unable to maintain both hind limbs extended straight, and was not able to raise the tarsal joint off the ground. Physiological parameters presented normal values. Due to the poor prognosis, euthanasia and necropsy were conducted. At necropsy, it was observed that in both hind limbs the gastrocnemius muscle was ruptured, presenting severe diffuse dark red color, severe enlargement, and moderate diffuse edema and emphysema. The rupture was complete and observed at both muscular insertions in the calcaneus bone. Besides the muscular alterations, the animal had a 2 centimeters fracture on the second sacral vertebra, associated with focally extensive hemorrhage in the spinal canal and meninges. Histologically the main findings were degeneration and severe diffuse necrosis of muscle fibers associated with severe hemorrhage, and mild infiltrate of neutrophils.Discussion: Fractures in cattle may occur due to multiples causes, however farm management and facilities play an important role in the incidence of these disorders. Slippery floors along with groups composed of animals of different sizes and ages are a major cause of injury in this species. The consequence of a vertebral fracture vary greatly according to the location and extent of the injury, the degree of spinal cord compression and which spinal anatomical structures are involved. Besides the direct damage caused by the fractures in the bone’s stability, changes can also occur in related structures, such as muscles and tendons, which are extremely important for the animal to maintain its normal stance and move adequately. One example is the trauma of gastrocnemius muscle that is found sporadically due to struggling. In this case it is conjectured that the pain and the spinal cord compression at the fracture’s location, lead to difficulty for the animal to rise, culminating with the ruptured muscles by overexertion. The characteristic position adopted by the animal was useful to establish the diagnosis, although necropsy was necessary to confirm it. Once the occurrence of this condition is infrequent, this report becomes important to aid veterinarians in order to differentiate it from other diseases of the musculoskeletal and nervous systems, including toxic conditions as Senna sp. and ionophore poisoning, besides nutritional myopathies such as vitamin E and selenium deficiency. Coxofemoral luxation and infectious diseases such as rabies and botulism should also be considered.

The myloglossus in a human cadaver study: common or uncommon anatomical structure?

Additional extrinsic muscles of the tongue are reported in literature and one of them is the myloglossus muscle (MGM). Since MGM is nowadays considered as anatomical variant, the aim of this study is to clarify some open questions by evaluating and describing the myloglossal anatomy (including both MGM and its ligamentous counterpart) during human cadaver dissections. Twenty-one regions (including masticator space, sublingual space and adjacent areas) were dissected and the presence and appearance of myloglossus were considered, together with its proximal and distal insertions, vascularisation and innervation. The myloglossus was present in 61.9% of cases with muscular, ligamentous or mixed appearance and either bony or muscular insertion. Facial artery provided myloglossal vascularisation in the 84.62% and lingual artery in the 15.38%; innervation was granted by the trigeminal system (buccal nerve and mylohyoid nerve), sometimes (46.15%) with hypoglossal component. These data suggest us to not consider myloglossus as a rare anatomical variant.

Nerve supply of the subscapularis during anterior shoulder surgery: definition of a potential risk area.

The purpose of the study was to evaluate the position of the subscapular nerves relative to surgical landmarks during exposure and to analyze the pattern of innervation of the subscapularis to avoid injury during anterior shoulder surgery. 20 embalmed human cadaveric shoulder specimens were used in the study. The muscular insertions of the subscapular nerves were marked and their closest branches to the musculotendinous junction and the coracoid process were measured in horizontal and vertical distances. In addition, the innervation pattern of each specimen was documented. 14/20 specimens showed an innervation of the subscapularis with an upper, middle and lower subscapular nerve branch. Even though the nerve branches were in average more than 2cm medial to the musculotendinous junction, minimal distances of 1.1-1.3cm were found. The mean vertical distance as measured from the medial base of the coracoid to the nerve innervation point into the muscle was 0.7cm for the upper nerve branch, 2.2cm for the middle nerve branch and 4.4cm for the lower nerve branch. The subscapularis has a variable nerve supply, which increases the risk of muscle denervation during open shoulder surgery. Dissection or release should be avoided at the anterior aspect of the subscapularis muscle more than 1cm medial to the musculotendinous junction. In approaches with a horizontal incision of the subscapularis, splitting should be performed at a vertical distance of 3.2-3.6cm to the coracoid base to avoid iatrogenic subscapular nerve injuries.

Sclerosing Bone Dysplasia from 16th Century Sardinia (Italy): A Possible Case of Camurati–Engelmann Disease

AbstractThe skeletal remains of a male aged 45–55 years displaying several bone anomalies were unearthed from the Alghero (Sardinia) plague cemetery ‘lo Quarter’, a burial site dating back to the 1582–1583 AD outbreak. The skeleton, whose stature is about 165 cm, presents a bilateral hyperostosis with increased diameter of the diaphyses of all the long bones of the upper and lower limbs; the metaphyses appear to be involved, while the epiphyses are spared. Marked thickening of the cranial vault is also evident. Radiological study showed irregular cortical thickening and massive endoperiosteal bone apposition; sclerotic changes are observed in the diaphysis of some metacarpals. Computed tomography (CT) cross sections of the long bones displayed a thickening of the cortical portion and endoperiosteal bone apposition.The individual was affected by a sclerosing bone dysplasia, a genetic disease characterized by increased bone density. In differential diagnosis, several sclerosing bone dysplasia, such as hyperostosis corticalis generalisata, craniodiaphyseal dysplasia, craniometadiaphyseal dysplasia, pachydermoperiostosis and Camurati–Engelmann disease, as well as other disorders characterized by sclerosing manifestations, such as Erdheim–Chester disease, mehloreostosis and skeletal fluorosis, need to be considered. The anomalies observed in skeleton 2179 fit with the features of Camurati–Engelmann disease, which is the most likely candidate for final diagnosis. It is highly challenging to evaluate how such a condition may have influenced the individual's lifestyle in terms of development, mobility and quality of life. This individual was probably symptomatic and must have experienced common clinical symptoms, such as pain in the limbs and fatigability. However, the strong development of the muscular insertions and the degenerative changes in the upper limbs suggest that the mobility problems should not have prevented him from reaching a mature age and from performing essential daily activities.The presented case is the unique paleopathological evidence of Camurati–Engelmann disease so far diagnosed. Copyright © 2015 John Wiley & Sons, Ltd.

A New Skull of Hyaenictis Gaudry, 1861 (Carnivora, Hyaenidae) Shows Incipient Adaptations to Durophagy

The European Miocene records a wide diversity of hyaenid ecomorphotypes represented by multiple genera. Among these, Hyaenictis Gaudry, 1861, is one of the least known. This genus includes four species from the late Miocene and Pliocene of the Old World, but in Europe Hyaenictis is only represented by two species, recorded by scarce and fragmentary remains: Hyaenictis graeca Gaudry, 1861, from Pikermi (MN12; Greece) and Hyaenictis almerai Villalta Comella and Crusafont Pairo, 1948, from Sant Miquel de Toudell (MN10; Valles-Penedes Basin, NE Iberia). Here, we describe a new skull of Hyaenictis aff. almerai from the Valles-Penedes site of Ronda Oest Sabadell Sector D (MN10), representing the most complete European specimen of the genus. In the presence of m2 and virtual lack of m1 metaconid, the described cranium more closely resembles Hyaenictis rather than any other medium- to large-sized European hyaenid. However, the new skull does not fit well with previously known Hyaenictis species, more closely resembling the bone-cracking Adcrocuta Kretzoi, 1938, in the development of premolar accessory cuspids and the possession of relatively broad cheek teeth. These and other features (strong mandibular muscular insertions and enamel microstructure) denote more durophagous adaptations than previously documented in Hyaenictis (considered a cursorial/dog-like hyaena), and favor the inclusion of H. aff. almerai in the transitional bone-cracking hyaenid ecomorphotype.

A large abelisaurid (Dinosauria, Theropoda) from Morocco and comments on the Cenomanian theropods from North Africa.

We describe the partially preserved femur of a large-bodied theropod dinosaur from the Cenomanian “Kem Kem Compound Assemblage” (KKCA) of Morocco. The fossil is housed in the Museo Geologico e Paleontologico “Gaetano Giorgio Gemmellaro” in Palermo (Italy). The specimen is compared with the theropod fossil record from the KKCA and coeval assemblages from North Africa. The combination of a distally reclined head, a not prominent trochanteric shelf, distally placed lesser trochanter of stout, alariform shape, a stocky shaft with the fourth trochanter placed proximally, and rugose muscular insertion areas in the specimen distinguishes it from Carcharodontosaurus, Deltadromeus and Spinosaurus and supports referral to an abelisaurid. The estimated body size for the individual from which this femur was derived is comparable to Carnotaurus and Ekrixinatosaurus (up to 9 meters in length and 2 tons in body mass). This find confirms that abelisaurids had reached their largest body size in the “middle Cretaceous,” and that large abelisaurids coexisted with other giant theropods in Africa. We review the taxonomic status of the theropods from the Cenomanian of North Africa, and provisionally restrict the Linnean binomina Carcharodontosaurus iguidensis and Spinosaurus aegyptiacus to the type specimens. Based on comparisons among the theropod records from the Aptian-Cenomanian of South America and Africa, a partial explanation for the so-called “Stromer’s riddle” (namely, the coexistence of many large predatory dinosaurs in the “middle Cretaceous” record from North Africa) is offered in term of taphonomic artifacts among lineage records that were ecologically and environmentally non-overlapping. Although morphofunctional and stratigraphic evidence supports an ecological segregation between spinosaurids and the other lineages, the co-occurrence of abelisaurids and carcharodontosaurids, two groups showing several craniodental convergences that suggest direct resource competition, remains to be explained.

Targeted Muscle Reinnervation of the Brachium: An Anatomic Study of Musculocutaneous and Radial Nerve Motor Points Relative to Proximal Landmarks

Targeted muscle reinnervation (TMR) offers enhanced prosthetic use by harnessing additional neural control from unused nerves in the amputated limb. The purpose of this study was to document the location and number of motor end plates to each muscle commonly used in TMR in the brachium relative to proximally based bony landmarks. We dissected 18 matched upper limbs (9 fresh-frozen cadavers). The locations of each of the nerves' muscular insertions into the medial biceps and brachialis were measured relative to the anterolateral tip of the acromion. The terminal branches to the lateral triceps were measured relative to the posterolateral tip of the acromion. Both the number of branches and the location of the muscular insertions were documented. Common descriptive statistics were used to describe the data. There was a median of 2 branches to the medial biceps located 19.6 cm from the anterolateral tip of the acromion (range, 15-25 cm). There was a median of 3.5 branches to the brachialis located 24.2 cm from the anterolateral tip of the acromion (range, 19-27.5 cm). There was a median of 2.5 branches to the lateral triceps located 21.6 cm from the posterolateral tip of the acromion (range, 11-29 cm). The mean distances to the primary branch muscle and the number of smaller branches were not significantly different when compared by sex or side. Motor points for the medial biceps, brachialis, and lateral triceps can be identified reliably using proximal landmarks in targeted muscle reinnervation. The data obtained from this study may assist the surgeon in localizing the nerve branches and muscular insertions for the commonly used muscles for TMR of the brachium.

A new species of Deutonura (Collembola: Neanuridae: Neanurinae) from north-eastern Algeria, and characterisation of two intraspecific lineages by their barcodes.

A new species of Deutonura, D. zana sp. nov., is described from north-eastern Algeria. It is morphologically similar in most characters to D. deficiens meridionalis and to D. luberonensis, both members of the D. phlegraea group, differing from the former by the absence of chaeta O on head, and from the later by the separation of tubercles Di and De on Th. I. The muscular insertion pattern of the new species is figured, and suggested as a potential new character for the taxonomy of Neanurinae. Deutonura zana sp. nov. is well characterised by its barcode sequence. Within the new species as morphologically defined, two groups of COI haplotypes, in individuals indistinguishable morphologically, are reported from two distinct mountain ranges. The need of a morphological assessment of demes diverging at significant infra-specific level in their barcodes is stressed.

ANATOMICAL VARIATION OF PALMARIS LONGUS: TENDINOUS ORIGIN AND FLESHY INSERTION

Address for Correspondence: Buddhadeb Ghosh, Lecturer, Department of Anatomy, Dr. Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh, India, 176001. Telephone: 9318962422 / +918894114210. E-Mail: debanatomy@gmail.com. Access this Article online Quick Response code Web site: *1Lecturer, Department of Anatomy, Dr. Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh, India. 2Asst Prof, Department of Anatomy, Dr. Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh, India. 3Sr.Resident, Department of Anatomy, Dr. Rajendra Prasad GovernmentMedical College, Tanda, Kangra, Himachal Pradesh, India. 4Prof. & Head, Department of Anatomy, Dr. Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh, India. 5Sr Resident, Department of Anatomy, Dr. Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh, India. A tendinous origin and fleshy insertion of palmaris longus muscle was observed in the left forearm during routine dissection which was performed on adult male cadaver in the department of Anatomy, Dr. Rajendra Prasad Government Medical College. It was having long tendinous origin from the medial epicondyle of the humerus and the surrounding deep fascia. It was fusiform at the lower middle of the forearm. The fleshy muscular insertion was noted to the flexor retinaculum and few muscular fibers interdigitate with flexor carpi ulnaris muscle and palmar aponeurosis. The length of tendon was 19 inches and fleshy muscular length was 11inches. The median nerve and ulnar nerve was covered by this fleshy insertion. This palmaris longus variation is helpful for the surgeon and the radiologist, orthopaedic, plastic surgeon during any diagnosis of the forearm because this fleshy part of muscle can compress the median nerve and ulnar nerve or it can be mistaken as a tumor or ganglion during radiological or clinical examination.

A great enigma of the Italian Renaissance: paleopathological study on the death of Giovanni dalle Bande Nere (1498-1526) and historical relevance of a leg amputation.

BackgroundThe Medici project consisted in archeological and paleopathological researches on some members of the great dynasty of the Italian Renaissance. The remains of Giovanni de’ Medici, so-called “dalle Bande Nere” (Forlì 1498- Mantua 1526) have not been investigated yet. The enigma of the fatal injury and leg amputation of the famous Captain excited curiosity of paleopathologists, medical scientists and Italian Society of Orthopedic and Traumatology which contributed to realize the project of exhumation and study of his skeletal remains. The aim of the study is to report the first anthropological and paleopathological results.Case presentationThe tomb of Giovanni and his wife Maria Salviati was explored and the skeletal remains were investigated. Anthropological and paleopathological examination defined: age at death, physical constitution and activity, skeletal diseases. The bones of the leg were studied macroscopically, under stereoscopic microscope, at X-ray and CT scans to detect type of injury and level of amputation.ConclusionsThe skeleton and muscular insertions of Giovanni revealed a young-adult and vigorous man, subjected to stresses of military activity since adolescence. Right tibia was amputated below the proximal half of diaphysis leaving long tibio-fibular stumps with a horizontal cut only at the lateral portion. Thus, the surgeon limited to complete the traumatic hemi-amputation. Amputation in the Sixteenth Century technically consisted in guillotine incisions below the knee using crescent shaped knife and bony saw, usually leaving a quite long tibial stump. Amputations in the Sixteenth Century were contaminated and grossly performed not providing vascular binding nor wound closure. The surgeon performed the procedure in conformity with surgical knowledge of that period.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2474-15-301) contains supplementary material, which is available to authorized users.

Anatomic and histological study of the rabbit mandible as an experimental model for wound healing and surgical therapies.

The rabbit is one of the most widely used models for studying bone remodeling or dental implant osseointegration but very few data are available about the rabbit's mandible. The aim of this work was to describe the anatomy of the rabbit mandible and to estimate the available bone volume for experimental studies. First, with a dissection, the morphology of the mandible was described and the mental foramen, the position of the main salivary glands and muscular insertions were located. Then, by X-ray imaging, the position of the inferior alveolar canal, the dental root courses and volume and bone density were described. Finally, with frontal sections of the mandible body, the rabbit's dental and alveolar bone histological structure were assessed. Thus, the relevance of the rabbit mandible as an experimental model for wound healing or surgical therapies was discussed.

Die topografische Beziehung des M. pronator quadratus zum Ansatz des M. brachioradialis - Implikationen für die Refixation nach palmarer Plattenosteosynthese distaler Radiusfrakturen

In open reduction and volar plate fixation of distal radius fractures, the pronator quadratus (PQ) muscle is usually detached at the radial edge of the distal radius. Repair of the muscle is reasonable for coverage of the plate and to maintain normal pronation of the forearm. However, repair of the muscle is not always satisfactory. In this study, the topographic relationship of both the PQ and the brachioradialis muscle (BR) insertions are investigated with regard to optimising the repair of the PQ in open reduction and volar plate fixation of distal radius fractures. Twelve forearm pairs fixed in formalin were examined. The muscular boundaries of the PQ and the insertion of the BR were dissected, photographs were taken and measured digitally. The average distance of the PQ insertion was 4.75 cm. Distally, a close topographic relationship exists between the insertions of both the PQ and BR. A fascial connection of both muscles was detected in all specimens. The average distance of the common insertion was 1.75 cm. After removal of the PQ fascia, 0.85 cm of common insertion remained. In 25 % a muscular connection between both the PQ and BR was detected after removal of the PQ fascia. Both the PQ and BR have a common connective tissue and partially a common muscular insertion. Detaching the PQ insertion with a part of the BR insertion in open reduction and volar plate fixation of distal radius fractures can presumably lead to a more stable repair of the PQ in contrast to a repair within the muscle.

New Technique for Correction of the Microform Cleft Lip Using Trans/Intraoral Approach

The traditional method of treating microform cleft lip with nose deformity uses upper lip external incision, finally leading to a small scar on the upper lip. Hereafter, we present a new method for the correction of microform cleft lip using trans/intraoral approach. The new surgical technique is characterized as (1) using trans/intraoral approach and no incisions on the skin of the upper lip, (2) reconstruction of the "cross" muscular structure using the abnormal muscular insertions at the base of nasal columella and the nasal alar to restore nose deformity, and (3) repair of the lip deformity using two small Z-plasties to get the aesthetic and functional outcome. Thirty patients with microform cleft lip were repaired with our technique, and good functional and aesthetic results of repaired noses and upper lips were obtained in most cases.

Secondary Cartilage Revealed in a Non-Avian Dinosaur Embryo

The skull and jaws of extant birds possess secondary cartilage, a tissue that arises after bone formation during embryonic development at articulations, ligamentous and muscular insertions. Using histological analysis, we discovered secondary cartilage in a non-avian dinosaur embryo, Hypacrosaurus stebingeri (Ornithischia, Lambeosaurinae). This finding extends our previous report of secondary cartilage in post-hatching specimens of the same dinosaur species. It provides the first information on the ontogeny of avian and dinosaurian secondary cartilages, and further stresses their developmental similarities. Secondary cartilage was found in an embryonic dentary within a tooth socket where it is hypothesized to have arisen due to mechanical stresses generated during tooth formation. Two patterns were discerned: secondary cartilage is more restricted in location in this Hypacrosaurus embryo, than it is in Hypacrosaurus post-hatchlings; secondary cartilage occurs at far more sites in bird embryos and nestlings than in Hypacrosaurus. This suggests an increase in the number of sites of secondary cartilage during the evolution of birds. We hypothesize that secondary cartilage provided advantages in the fine manipulation of food and was selected over other types of tissues/articulations during the evolution of the highly specialized avian beak from the jaws of their dinosaurian ancestors.

The Sunghir 3 Upper Paleolithic Juvenile: Pathology versus Persistence in the Paleolithic

AbstractThe Mid Upper Paleolithic Sunghir 3 late juvenile early modern human, from the most elaborate burial in the Pleistocene, had pathologically foreshortened and anteriorly bowed femora and, based on her dental enamel hypoplasias and transverse lines, sustained severe and persistent systemic stress throughout her decade of life. Her modest femoral and tibial asymmetry and her femoral bicondylar angles indicate non‐pathological patterns of posture and locomotion. The levels of rigidity for her weight‐bearing tibiae and the non‐dominant left arm reflect normal weight‐bearing and manipulation. These indicators are combined with an elevated level of right humeral strength, leading to pronounced humeral diaphyseal asymmetry, combined with elevated muscular insertion asymmetry. In combination with marked upper limb muscle markings and normal levels of bone formation, these reflections of her robustness indicate that she was fully mobile and participated actively in the tasks of her social group. There is no indication of the skeletal hypotrophy/atrophy that would be associated with less than full participation in the mobility and subsistence of her social group. As such, Sunghir 3 joins a growing list of developmentally or degeneratively pathological Late Pleistocene humans who nonetheless remained mobile and active. Copyright © 2012 John Wiley & Sons, Ltd.

Magnetic resonance imaging evaluation of discal attachment of superior head of lateral pterygoid muscle in individuals with symptomatic temporomandibular joint

There has been much speculation on the role of the lateral pterygoid muscle (LPM) in temporomandibular joint (TMJ) internal derangement. As a result, this muscle has been the focus of many reports attempting to understand its possible role in TMJ internal derangement. Magnetic resonance (MR) imaging exams of 108 TMJ disorder patients were assessed for types of morphologic insertion of the superior head of LPM to the condyle-disc complex and possible correlation with disc position. The investigation was made on the sagittal T1-weighted MR images in closed- and open-mouth positions. There was a lack of correlation between attachment pattern of the superior head of LPM and presence or absence of anterior disc displacement. The explanation of anterior disc displacement based on the attachment type of the superior head of LPM is unlikely; the type of muscular insertion does not appear to have a predictive or prognostic value for TMJ internal derangement.

Anancylus Rosanae(Gastropoda: Pulmonata), New Genus and New Species, from Iguazú National Park, Argentina

Seventeen species of ancylids occur in southern South America, seven in Argentina. Anancylus rosanae, n. gen. et sp., is described based on characters of the shell, radula, jaw and reproductive system. This new genus, found in the upper Iguazu River rapids, Iguazu National Park, Misiones Province, Argentina, has the following distinctive features: patelliform shell, usually low, with a circular apex located at the anterior end of the shell; three adductor muscles: large posterior (twice the length of the anterior muscles) and two tear-shaped anterior; adhesive epithelium between the two anterior muscular insertions; no difference between the plates of the jaw.