A pterosaurian vertebra from the Upper Cretaceous of the Saratov Region

A dorsal vertebra referred to as Azhdarchidae indet. from the Rybushka Formation (Upper Cretaceous, Lower Campanian) of the Beloe Ozero locality in the Saratov Region is described. Its vertebral centrum has a hypapophysis and, at the base of the neural arch, there is a large pneumatic foramen. The vertebra possibly belongs to Volgadraco bogolubovi Averianov, Arkhangelskii et Pervushov, 2008, described from the Rybushka Formation of the Shirokii Karamysh 2 locality in the Saratov Region.     

A new late Cretaceous azhdarchid (Pterosauria,Azhdarchidae) from the Volga Region

A new azhdarchid genus and species, Volgadraco bogolubovi gen. et sp. nov., is described based on an anterior fragment of the mandibular symphysis (mandibular beak) and some postcranial elements from the Rybushka Formation (Upper Cretaceous, Lower Campanian) of the Shirokii Karamysh 2 locality, Saratov Region. The new taxon is intermediate in size and vascularization of the mandibular beak between medium-sized Turonian-Santonian azhdarchids (Azhdarcho, Bakonydraco) and the giant Maastrichtian azhdarchid Quetzalcoatlus.     

Brief communication: Developmental versus functional three‐dimensional geometric morphometric‐based modularity of the human proximal humerus

The proximal humerus is formed by three secondary ossification centers during the postnatal trajectory of the human infant. The ossification centers later grow into the structures of the articular surface, major tubercle, and minor tubercle. There is a purported functional division between the articular surface and the tubercles, with the articular surface mainly responsible for the range of movement of the shoulder joint, and the tubercles bearing the insertions of the rotator cuff muscles, mainly devoted to securing the joint against humeral displacement. Using three‐dimensional geometric morphometrics, we tested the presence of such developmental and functional divisions in the proximal humerus, applying the RV coefficient of Escoufier to these a priori hypothesized modules. Our results indicate that the proximal humerus might be a generally integrated structure. However, a weak signal for modular configuration was present, with slightly stronger support for the two modules depicting the boundaries between the purported functional regions of the epiphysis: the articular surface and the tubercles. Am J Phys Anthropol 154:459–465, 2014. © 2014 Wiley Periodicals, Inc.     

A NEW GENUS OF ICHTHYOSAUR FROM THE LOWER CRETACEOUS OF WESTERN CANADA

Abstract:  A new fauna of Lower Cretaceous (Albian) ichthyosaurs, which includes at least one new genus and species, was recovered from deposits of the Loon River Formation at Hay River, Northwest Territories, Canada. All Cretaceous ichthyosaurs have been referred to a single genus, Platypterygius . The Loon River Formation material, however, does not satisfy the diagnosis for Platypterygius , and it is distinctive enough to warrant the erection of a new genus and species of ichthyosaur. Maiaspondylus lindoei gen. et sp. nov. is distinguished from other ichthyosaurs by an extensive overlapping contact of the jugal and the maxilla; marginal teeth with smooth crowns, fluted cementum, lingual curvature and implantation in a dental groove; and humerus with isomorphic proximal and distal ends, featuring three distal articular facets in which the medial articular facet is smaller than the lateral facets. The holotype and referred material is described here, and the relationship of Maiaspondylus to other ophthalmosaurs is discussed.     

First report of dinosaurian claws from the Late Triassic of India

The Late Triassic Tiki Formation has yielded five isolated nearly complete claws or ungual phalanges from a fossil locality, which are described in detail and compared with other Late Triassic tetrapods. Of these, four ungual phalanges are slender, asymmetric, ventrally recurved, transversely compressed, and contain deep collateral grooves on either side, a low median keel on the proximal articular surface and a prominent proximoventral flexor tubercle showing their high similarity to the theropod dinosaurs. The remaining claw is unlike that of any theropods in terms of high robusticity and near symmetry. However, as in dinosaurs it is ventrally recurved and contains deep lateral grooves, a small flexor tubercle, lateromedially extended proximal articular surface with a distinct median keel and is considered as belonging to an indeterminate dinosaur. Although it is not possible to ascertain whether the unguals belong to a single taxon or multiple taxa, this new find points towards the presence of small dinosaurs in the Late Triassic Tiki fauna.     

New genera of baleen whales (Cetacea,Mammalia) from the Miocene of the northern Caucasus and Ciscaucasia: 3. Zygiocetus gen. nov. (Middle Sarmatian,Adygea)

Based on an almost complete skeleton (skull, scapula fragment, humerus, ulna, radius, 7 cervical, 12 thoracic, 17 lumbar and caudal vertebrae, sternum, and hyoid), a new cetotheriid, Zygiocetus nartorum gen. et sp. nov., is described. It comes from the Middle Sarmatian beds (Upper Miocene) of the Krasnooktyabr’sk Formation of the Polevoe 1 locality (Republic of Adygea).     

An abelisaurid humerus from the Upper Cretaceous of India

The Lameta Formation (Upper Cretaceous, Maastrichtian) of India has yielded abundant fossils of abelisaurid theropods, including bones from the cranium, vertebral column, pectoral and pelvic girdles, and hindlimb. However, the forelimbs of Indian abelisaurids remain unknown. Here we describe an abelisaurid humerus from exposure of the Lameta Formation near the village of Rahioli in northwestern India. This new material exhibits derived traits that are distinctive of Abelisauridae, for example an articular head that is hemispherical in proximal view, thus establishing the specimen as the first abelisaurid humerus from India.     

A musculoskeletal model of the equine forelimb for determining surface stresses and strains in the humerus--part I. Mathematical modeling

Knowledge of the forces that act upon the equine humerus while the horse is standing and the resulting strains experienced by the bone is useful for the prevention and treatment of fractures and for assessing the proximolateral aspect of the bone as a site for obtaining autogenous bone graft material. The first objective was to develop a mathematical model to predict the loads on the proximal half of the humerus created by the surrounding musculature and ground reaction forces while the horse is standing. The second objective was to calculate surface bone stresses and strains at three cross sections on the humerus corresponding to the donor site for bone grafts, a site predisposed to stress fracture, and the middle of the diaphysis. A three-dimensional mathematical model employing optimization techniques and asymmetrical beam analysis was used to calculate shoulder muscle forces and surface strains on the proximal and mid-diaphyseal aspects of the humerus. The active shoulder muscles, which included the supraspinatus, infraspinatus, subscapularis, and short head of the deltoid, produced small forces while the horse is standing; all of which were limited to 4.3% of their corresponding maximum voluntary contraction. As a result, the strains calculated at the proximal cross sections of the humerus were small, with maximum compressive strains of -104microepsilon at the cranial aspect of the bone graft donor cross section. The middle of the diaphysis experienced larger strain magnitudes with compressive strains at the lateral and the caudal aspects and tensile strains at the medial and cranial aspects (-377microepsilon and 258microepsilon maximum values, respectively) while the horse is standing. Small strains at the donor bone graft site do not rule out using this location to harvest bone graft tissue, although strains while rising to a standing position during recovery from anesthesia are unknown. At the site common to stress fractures, small strains imply that the stresses seen by this region while the horse is standing, although applied for long periods of time, are not a cause of fracture in this location. Knowing the specific regions of the middle of the diaphysis of the humerus that experience tensile and compressive strains is valuable in determining optimum placement of internal fixation devices for the treatment of complete fractures.     

New postcranial elements of the Thalassodrominae (Pterodactyloidea,Tapejaridae) from the Romualdo Formation (Aptian–Albian), Santana Group,Araripe Basin,Brazil

Tapejarids are edentate pterosaurs recovered mainly from Early Cretaceous deposits. They are diagnosed by five synapomorphies, among which only one is postcranial: a broad and well‐developed tubercle at the ventroposterior margin of the coracoid. Regarding the clade Thalassodrominae, most phylogenetic studies are based on cranial elements, as postcranial skeletons of these pterosaurs are rare. Here, new postcranial material from the Romualdo Formation (Aptian–Albian) from the Araripe Basin is described. The material comprises the three posteriormost cervical vertebrae, the first seven dorsal vertebrae (fused into a notarium), both scapulocoracoids, a fragment of a sternum, a partial right humerus, a small fragment of a 4th phalanx of the wing finger, a distal extremity of the right femur and the proximal portions of both tibia and fibula. Comparisons with other specimens and morphological features examined in a phylogenetic context, such as the presence of three foramina lateral and dorsal to the neural canal of the cervical vertebrae, the presence of a notarium and a pneumatic foramen on the ventral side of the proximal portion of the humerus, allow the assignment of this specimen as Thalassodrominae indet. Regarding palaeobiogeographical aspects, to date, this clade is exclusively found in the Romualdo Formation. It is the most complete postcranial material assigned to the Thalassodrominae described so far.     

Cross-sectional geometric properties along the diaphysis of femur and humerus in chimpanzees and humans

The cross-sectional geometric parameters were determined serially along the diaphysis of 3 paired humeri and femora of chimpanzees by using the computed X-ray tomographic scans, and compared with those of humans. In magnitude, the femoral parameters were greater and humeral parameters were less, respectively, in humans than in chimpanzees. While the changing pattern among the parameters along the diaphysis was very similar both in the femur and humerus of chimpanzees, the pattern in the humans was reversed between the cross-sectional area and area moments of inertia. In chimpanzees, the femoral parameters increased toward the most proximal diaphysis, whereas humeral parameters yielded a moderate peak in a portion slightly proximal to mid-shaft. Potential mechanisms responsible for these findings were discussed.     

On a tomistomine crocodile (Crocodylidae,Tomistominae) from the Middle Eocene of Ukraine

A dentary fragment and osteoderm of the crocodile Tomistominae indet. from the Middle Eocene (Early Lutetian) Ikovo locality (Lugansk Region, Ukraine) is described.     

Short-necked plesiosaurs of the family Polycotylidae from the Campanian of the Saratov Region

Fragments of the anterior part of a mandibular rostrum and a maxillary bone of the plesiosaur Polycotylidae indet. from the Karyakino and Beloe Ozero localities of the Saratov Region (Upper Cretaceous, Campanian) are described. The specimens belong to a relatively long-snouted polycotylid with a mandibular symphysis incorporating 13 pairs of teeth. A unique feature of this plesiosaur is the fact that, in the symphysis, the splenial extends to the very anterior end of the rostrum. The polycotylid from the Campanian of the Saratov Region is probably closely related or identical to Georgiasaurus from the Santonian of the Penza Region, in which structural details of the mandibular symphysis remain uncertain.     

Taxonomy of the fossil grylloblattid nymphs (Insecta: Grylloblattida)

Nymphs of fossil grylloblattid insects are revised. Newly described taxa are Lemmatonympha gracilissima gen. et sp. nov. and Kaltanympha vorcutensis sp. nov. from the Verkhne-Syr’yaginsk locality (Ufimian, Lek-Vorkuta Formation in the Vorkuta Coal Basin), genera Sylvalitoralis gen. nov. and Tshebardanympha gen. nov. from the Tshekarda locality (Kungurian, Koshelevka Formation, Middle Urals), Tataronymphakamensis gen. et sp. nov. from the Tikhie Gory locality (Lower Kazanian, linguloid beds of the Baitugan Formation, Tatarstan), and Kaltanympha ornata sp. nov. from the Kerbo locality (Upper Tatarian, lower part of the Degali Formation, Evenki Autonomous Region). Liomopterites (?) gracilis Sharov, 1961 from Lower Kazanian deposits of the Kuznetsk Formation in the Kuznetsk Basin is transferred to the genus Kaltanympha Sharov, 1961; Permonympha arcuata Sharov, 1957 from the same locality is synonymized under Permonympha gracile Sharov, 1957; the nymph described from the Karatau locality (Upper Jurassic, Karabastau Formation in southern Kazakhstan) as Blattogryllus karatavicus Rasnitsyn, 1976 is excluded from grylloblattids. Keys to extinct grylloblattid nymphs are provided.     

Modeling the stability of the human glenohumeral joint during external rotation

An analytical model of the human glenohumeral joint was developed to predict glenohumeral kinematics and investigate how the glenohumeral capsule and articular contact between the humeral head and the glenoid stabilize the joint. This was performed during a simulation of an apprehension clinical exam or the cocked phase of throwing, when the humerus is susceptible to anterior instability or dislocation. Contact between the joint surfaces was modeled using a deformable articular contact method and the capsule was modeled as five elements with the ability to wrap around the surface of the humeral head. Experimental measurements (Novotny et al., Journal of Shoulder and Elbow surgery, 1998, 7, 629-639) provided geometric data from four in vitro specimens and kinematic results to validate model predictions. Material properties were taken from the literature. An equilibrium approach was used with the forces and moments produced by the ligaments and surface contact balanced against those applied externally to the humerus during external rotation of the abducted and extended humerus. The six equilibrium equations were solved for the position and orientation of the humerus. The center of the humeral head translated posteriorly and superiorly with external rotation. Model predictions for translational and rotational ranges of motion were not significantly different from experimental findings; however, at individual moment increments, the model underestimated the external rotation and overestimated the superior-inferior position of the humerus relative to the glenoid. The anterior band of the inferior glenohumeral ligament increased in tension with external rotation, while the axillary pouch and posterior band decreased in tension. Contact area, stress and force increased with external rotation and the contact area moved posteriorly and inferiorly around the rim of the glenoid. The model results provide information on how the relationship between the ligament element tensions and contact forces may act to avoid glenohumeral instability.     

A new seabird (Aves, cf. Phaethontidae) from the Lower Eocene phosphates of Morocco

A proximal part of humerus from the basal Ypresian (lowermost Eocene) of the Ouled Abdoun Basin, Morocco, is described as a new genus and species tentatively assigned to the Phaethontidae (tropicbirds). This fossil possibly represents the oldest record of the Phaethontidae and markedly differs from Lithoptila, a contemporaneous Prophaethontidae from the same locality. This new taxon lived in a tropical climate and was probably an efficient flier with pelagic habits, like extant tropicbirds of the genus Phaethon.     

A description of the Omo I postcranial skeleton, including newly discovered fossils

Recent fieldwork in the Kibish Formation has expanded our knowledge of the geological, archaeological, and faunal context of the Omo I skeleton, the earliest known anatomically modern human. In the course of this fieldwork, several additional fragments of the skeleton were recovered: a middle manual phalanx, a distal manual phalanx, a right talus, a large and a small fragment of the left os coxae, a portion of the distal diaphysis of the right femur that conjoins with the distal epiphysis recovered in 1967, and a costal fragment. Some researchers have described the original postcranial fragments of Omo I as anatomically modern but have noted that a variety of aspects of the specimen's morphology depart from the usual anatomy of many recent populations. Reanalysis confirms this conclusion. Some of the unusual features in Omo I--a medially facing radial tuberosity, a laterally flaring facet on the talus for the lateral malleolus, and reduced dorsovolar curvature of the base of metacarpal I--are shared with Neandertals, some early modern humans from Skhul and Qafzeh, and some individuals from the European Gravettian, raising the possibility that Eurasian early modern humans inherited these features from an African predecessor rather than Neandertals. The fragment of the os coxae does not unambiguously diagnose Omo I's sex: the greater sciatic notch is intermediate in form, the acetabulum is large (male?), and a preauricular sulcus is present (female?). The preserved portion of the left humerus suggests that Omo I was quite tall, perhaps 178-182 cm, but the first metatarsal suggests a shorter stature of 162-173 cm. The morphology of the auricular surface of the os coxae suggests a young adult age.     

A NEW PARASEMIONOTID-LIKE FISH FROM THE LOWER TRIASSIC OF JURONG, JIANGSU PROVINCE, SOUTH CHINA

Abstract:  Based on a well-preserved specimen from the Early Triassic Lower Qinglong Formation exposed at Qingshan Quarry, Jurong, Jiangsu Province of China, the new taxon Peia jurongensis gen. et sp. nov. is named and described with anatomical details of its dermal skull, neurocranium and postcranial skeleton. The new taxon is characterized by the following set of characters: shallow V-shaped, tuber-like rostral; anterior part of frontal widened to roughly same width as its posterior part; roughly squared parietal; supraorbital absent; wide and slightly posteriorly inclined preopercle; five small ossifications present in dorsal half of preopercle; preopercular canal shifting anteriorly in ventral half of the preopercle, and reaching the anteroventral corner of this bone; dermosphenotic joining the skull roof and with a descending lamina; numerous branchiostegal rays. Comparisons are made between the new taxon and several parasemionotids from the same locality; a discussion is carried out on the distribution and evolution of several characters in halecomorphs and other closely related neopterygians.     

Diversity of Middle Jurassic Turtles from the Berezovsk Quarry Locality,Krasnoyarsk Region,Russia: Morphology and Histological Study

Abstract—Morphology and histology of several fragmentary turtle specimens from the Middle Jurassic locality in the Berezovsk quarry (Krasnoyarsk Region, Russia) are described, including Testudines indet. 1 (costal VIII), Testudines indet. 2 (two ornamented shell fragments), and Testudines indet. 3 (distal part of a humerus), and also skeletal elements of Annemys sp. (Xinjiangchelyidae) represented by mass material in the same locality. It is shown that Testudines indet. 1 and 3 probably belong to one or two taxa of basal aquatic turtles, while Testudines indet. 2 is most likely an abnormal Annemys sp. The presumable presence of basal turtles in the Berezovsk Quarry Assemblage agrees with the fact that they are present in other Middle Jurassic turtle assemblages of Asia.     

Le Crocodilien longirostre Gavialosuchus dans le Miocène moyen de Polastron (Gers,France)

A left maxilla fragment from the newly discovered Miocene vertebrate locality of Polastron (Gers, southwestern France) is described and referred to the longsnouted eusuchian crocodilian Gavialosuchus, which had never been reported from the Miocene of this area, in which crocodilian remains are scarce. On the basis of its mammal fauna, the locality is slightly older than Sansan. Although Gavialosuchus is usually found in marine beds, its occurrence in the fluviatile deposits of Polastron shows that it also inhabited rivers.     

New data concerning the familial position of the genus Euronyctibius (Aves, Caprimulgiformes) from the paleogene of the Phosphorites du Quercy, France

The extinct genus Euronyctibius was described from a proximal part of humerus from an unknown locality in the Phosphorites du Quercy, France. New material referable to this genus shows that Euronyctibius is more closely related to the Steatornithidae than to the Nyctibiidae. It is here attributed to a stem group representative of the family Steatornithidae. The Recent Steatornithidae includes only the South American monospecific genus, Steatornis, but during the Paleogene this family was also present in North America as well as in Europe.