Fossil cocoons associated with a dinosaur egg from Patagonia,Argentina

Abstract: Eight fossil (Cretaceous) insect cocoons were discovered within the infillings of a broken dinosaur egg of a clutch from a Patagonian locality. Cocoons are considered to be in situ based on detailed preservation of thin, delicate walls with surface texture, infillings that are similar to the surrounding rock matrix and the clustered distribution of cocoons in only one egg out of the clutch of five eggs. According to the shape, size, and thin wall with surface texture, the cocoons are interpreted as having been produced by wasps. The wasps may have been attracted to the egg because of the presence of scavenging insects feeding on the decaying organic matter, or they may have been attracted to spiders feeding on the scavenging insects. In either scenario, after attacking the insects or spiders inside the sand infillings of the egg, the wasp larvae produced the cocoons described herein. The presence of wasps, which are at the top of the scavenging food webs, suggests that a complex community of invertebrates would have developed around rotten dinosaur eggs.     

The functions of laryngeal air sacs in primates: a new hypothesis

A possible function of laryngeal air sacs in apes and gibbons was investigated by examining the relationships between air sac distribution, call rate, call duration and body weight in a phylogenetic context. The results suggest that lack of sacs in the smaller gibbons and in humans is a derived feature. Call parameters in primates, such as rate and duration, scaled to resting breathing rate (and therefore to body weight) only in species without air sacs, which appear to modify these relationships. Apes and larger gibbons may be able to produce fast extended call sequences without the risk of hyperventilating because they can re-breathe exhaled air from their air sacs. Humans may have lost air sacs during their evolutionary history because they are able to modify their speech breathing patterns and so reduce any tendency to hyperventilate.     

Dentition and histology in titanosaurian dinosaur embryos from Upper Cretaceous of Patagonia,Argentina

Abstract: Exceptionally preserved sauropod embryos from the Late Cretaceous Anacleto Formation in Auca Mahuevo (Neuquén Province, Argentina) have provided fundamental information on titanosaurian ontogeny. This paper describes the dental composition, disposition and microstructure of the specimens. Embryonic teeth show size disparity, with lengths that vary from 1 to 3 mm and diameters ranging from 0.15 to 0.26 mm, with the most frequent length values between 2.5 and 3 mm. Apparently, a typical ‘pencil‐like’ tooth morphology and a dental formula of Pm 4, M 7–8/D10? remained constant during titanosaurian ontogeny, whereas the arrangement of teeth in the skull shows notable ontogenetic changes. Absence of wear facets on teeth suggests a lack of prenatal chewing movements. The enamel proportion is significantly higher in embryos than in mature titanosaurs, which suggests that this relationship varies during ontogeny. Embryonic bony tissue is composed of highly vascularized, cellular woven bone. The absence of osteonal tissue, the high degree of vascularization, the presence of numerous osteocytes and poor development of periosteal bone reveals that the Auca Mahuevo titanosaurs would have had a high early growth rate and that they were buried at a relatively advanced embryonic stage.     

Rioarribasaurus,a new name for a Late Triassic dinosaur from New Mexico (USA)

The Late-Triassic-dinosaur generic nameCoelophysis Cope 1889 (type species C.bauri [Cope 1887]) is a nomen dubium because the lectotype of C.bauri, AMNH 2722, is four sacral vertebrae and a pubic process of the ilium that are not diagnostic. Dinosaur specimens from the famous Whitaker (“Coelophysis”) quarry in the Rock Point Member of the Chinle Formation at Ghost Ranch, New Mexico thus lack a valid name. We create a new genus and species name,Rioarribasaurus colberti, for these specimens.     

Vertebral pneumatic structures in the Early Cretaceous sauropod dinosaur Pilmatueia faundezi from northwestern Patagonia,Argentina

One of the diagnostic characters of dicraeosaurid sauropods is a reduction of pneumatization of dorsal and caudal vertebrae relative to their Flagellicaudata sister taxon, Diplodocidae. Here, we analyse pneumatic structures in the dicraeosaurid sauropod Pilmatueia faundezi, compare them to those of diplodocoids and report the first record of camerate chambers in a dicraeosaurid. The pneumatic structures are in a posterior cervical centrum (MLL-Pv-002) and consist of lateral pneumatic fossae on the centrum that communicate internally with large camerae. By contrast, Pilmatueia's dorsal and caudal vertebrae (MLL-Pv-005-016) lack pneumatic fossae on the centra, which is consistent with the previously reported reduced pneumaticity in dicraeosaurids. Nevertheless, the base of the neural arch and possibly the base of the bifid neural spines of a posterior dorsal vertebra (MLL-Pv-005) show pneumatic internal chambers. The pneumatic features of the Pilmatueia cervical centrum and dorsal neural arch we describe indicate that the degree of pneumatization is variable within dicraeosaurids.     

A complex hyobranchial apparatus in a Cretaceous dinosaur and the antiquity of avian paraglossalia

The highly specialized feeding apparatus of modern birds is characterized in part by paraglossalia, triangular bones or cartilages in the tongue that constitute part of the rarely fossilized hyobranchial apparatus. Here, we report on a new, juvenile specimen of the ankylosaurid dinosaur Pinacosaurus grangeri Gilmore, 1933 that provides the first evidence of paraglossalia outside of crown group Aves. The specimen is remarkable in preserving a well‐ossified hyobranchial apparatus, including paired paraglossalia, first and second ceratobranchials, epibranchials, and evidence of a median cartilaginous basihyal. Reassessment of Edmontonia, another ankylosaur, also reveals evidence of bony paraglossalia. Ankylosaur paraglossalia closely resemble those of birds, but are relatively larger and bear prominent muscle scars, supporting the hypothesis that ankylosaurs had fleshy, muscular tongues. The other hyobranchial elements, surprisingly, resemble those of terrestrially feeding salamanders. Ankylosaurs had reduced, slowly replacing teeth, as evidenced from dental histology, suggesting that they relied greatly on their tongues and hyobranchia for feeding. Some curved, rod‐like elements of other dinosaur hyobranchia are reinterpreted as second ceratobranchials, rather than first ceratobranchials as commonly construed. Ankylosaurs provide rare fossil evidence of deep homology in vertebrate branchial arches and expose severe biases against the preservation and collection of the hyobranchial apparatus. In light of these biases, we hypothesize that paraglossalia were present in the common ancestor of Dinosauria, indicating that some structures of the highly derived avian feeding apparatus were in place by the Triassic Period. © 2015 The Linnean Society of London     

Evidence for amylase in avian salivary glands

Four glands of the house sparrow, chicken and turkey were examined histologically and for their content of amylase. These were the external and intermediate mandibular glands, the maxillary gland and glandula anguli oris of the sparrow and the anterior and posterior mandibular, maxillary and anguli oris glands of the chicken and turkey. Amylase was determined by a starch substrate slide method and by biochemical assay. General morphology and mucopolysaccharide staining are described. All four glands of the sparrow demonstrated significant amylolytic activity by the assay. In the external mandibular and anguli oris glands this activity could be traced to mucous and seromucous cells of origin by means of the starch substrate slide procedure. None of the glands of the chicken or turkey displayed significant amylolytic activity.     

Evidence for predatory control of the invasive round goby

We coupled bioenergetics modeling with bottom trawl survey results to evaluate the capacity of piscivorous fish in eastern Lake Erie to exert predatory control of the invading population of round goby Neogobius melanostomus. In the offshore (>20 m deep) waters of eastern Lake Erie, burbot Lota lota is a native top predator, feeding on a suite of prey fishes. The round goby invaded eastern Lake Erie during the late 1990s, and round goby population size increased dramatically during 1999–2004. According to annual bottom trawl survey results, round goby abundance in offshore waters peaked in 2004, but then declined during 2004–2008. Coincidentally, round goby became an important component of burbot diet beginning in 2003. Using bottom trawling and gill netting, we estimated adult burbot abundance and age structure in eastern Lake Erie during 2007. Diet composition and energy density of eastern Lake Erie burbot were also determined during 2007. This information, along with estimates of burbot growth, burbot mortality, burbot water temperature regime, and energy densities of prey fish from the literature, were incorporated into a bioenergetics model application to estimate annual consumption of round goby by the adult burbot population. Results indicated that the adult burbot population in eastern Lake Erie annually consumed 1,361 metric tons of round goby. Based on the results of bottom trawling, we estimated the biomass of yearling and older round goby in offshore waters eastern Lake Erie during 2007–2008 to be 2,232 metric tons. Thus, the adult burbot population was feeding on round goby at an annual rate equal to 61% of the estimated round goby standing stock. We concluded that the burbot population had high potential to exert predatory control on round goby in offshore waters of eastern Lake Erie.     

Osteology and relationships of a new theropod dinosaur from the Middle Jurassic of Patagonia

Abstract:  A new taxon of theropod dinosaur is described as Condorraptor currumili gen. et sp. nov., from the Middle Jurassic (Callovian) Cañadón Asfalto Formation of Chubut Province, Argentinean Patagonia. The taxon is represented by a single fragmentary postcranial skeleton. Although incompletely known, Condorraptor is the second most complete theropod from the Middle Jurassic of Gondwana. The new taxon is characterized by the absence of a posterior incision between the fibular condyle and the medial side of the proximal articular end of the tibia, the pleurocoels in the anterior cervicals being situated posteroventral to the parapophyses, and the presence of a pronounced 'step' between the distal articular facet and shaft of Mt IV. Pneumatic features of the vertebral column show strong variation between the left and right side. Condorraptor gen. nov. can be referred to the Tetanurae and is a representative of a global radiation of basal tetanurans in the Early to Mid Jurassic.     

Innate plasticity of a predatory behavior: nonlearned context dependence of avian flush-displays

If a foraging adaptation comprises a signal for sensory exploitationof prey, does the behavior and its use develop through learning,like many foraging behaviors or does it depend on nonlearnedstereotypical motor actions, like many signals for sensory exploitation?We asked whether the visually conspicuous motor pattern of bodypivoting with spread tail and wings used by the painted redstart(Myioborus pictus) to flush insect prey is a nonlearned phenotypictrait. The motion pattern and the increase in these displaysunder branches (context dependence based on physical propertiesof the habitat) help the wild birds in foraging because preythat rest on substrates is visually stimulated, flushed intothe air, and consequently chased in aerial pursuits. In unrewardedconditions in the aviary, both the foraging-experienced adultsand the foraging-naive hand-raised fledglings increased thefrequency of flush-displays at locations with substrates abovebirds, recreating the pattern of foraging observed in adultsin their natural habitats. The results imply that parent–offspringcultural transmission or learning during foraging is not requiredfor the development of both the display motion pattern and theadaptive context-dependent increase in display frequency. Sucha nonlearned context dependence based on physical propertiesof the habitat is remarkable considering that avian foragingcontext-dependent plasticity is often based on learning. Wehypothesize that this innate character of the signals may bea result of evolution to exploit universal properties of visuallytriggered escape behaviors of various insects that are predictablyflushed from their resting sites in the habitat.     

Parataxonomic review of the Upper Cretaceous dinosaur eggshells belonging to the oofamily Megaloolithidae from India and Argentina

The eggshell oospecies from India and Argentina are compared and reviewed in detail. These eggshells resemble each other in having a nodular outer surface ornamentation and clearly arched growth lines of the shell units. Microstructurally, the eggshell oospecies belonging to the oofamily Megaloolithidae shows fan-like shell units, which are sharply separated from each other throughout the thickness of the eggshell and can be traced up to the surface of the eggshell. Comparisons between four oospecies from India and Argentina reveal three groupings, which show similarities between megaloolithids of both countries: (1) Megaloolithus jabalpurensis, M. matleyi and M. patagonicus; (2) M. cylindricus, M. rahioliensis and Tipo 1d; and (3) M.megadermus and Tipo 1e. The other two types of eggshell oospecies from India and Argentina show partially fused external nodes and shell units. As a result, growth lines enter into the adjacent shell units with a marked concavity. A new oogenus Fusioolithus have been erected due to fusion between shell units and tubospherulitic morphotype, which include two new oospecies F. baghensis and F. berthei. Till date, morphostructurally, a total of 15 eggshell oospecies belonging to different oofamilies have been recorded from India and seven oospecies from Argentina.     

Sisyrinchium humahuacense of sect. Segetia a new species from Argentina

Abstract

A new species from the Andean region of northwestern Argentina is described and illustrated: Sisyrinchium humahuacense. This species can be distinguish from its closest related species by three main characters: the presence of a conspicuous horizontal rhizome, the colour of the flowers and the presence of rudimentary leaves not splitting in fibers. A phylogenetic analysis based on DNA sequences supported the inclusion of S. humahuacense within the genus and as part of the section Segetia. Also, a key to species to identify S. humahuacense is presented herein.     

A new troodontid theropod dinosaur from the lower Cretaceous of Utah

Background

The theropod dinosaur family Troodontidae is known from the Upper Jurassic, Lower Cretaceous, and Upper Cretaceous of Asia and from the Upper Jurassic and Upper Cretaceous of North America. Before now no undisputed troodontids from North America have been reported from the Early Cretaceous.

Methodology/Principal Findings

Herein we describe a theropod maxilla from the Lower Cretaceous Cedar Mountain Formation of Utah and perform a phylogenetic analysis to determine its phylogenetic position. The specimen is distinctive enough to assign to a new genus and species, Geminiraptor suarezarum. Phylogenetic analysis places G. suarezarum within Troodontidae in an unresolved polytomy with Mei, Byronosaurus, Sinornithoides, Sinusonasus, and Troodon + (Saurornithoides + Zanabazar). Geminiraptor suarezarum uniquely exhibits extreme pneumatic inflation of the maxilla internal to the antorbital fossa such that the anterior maxilla has a triangular cross-section. Unlike troodontids more closely related to Troodon, G. suarezarum exhibits bony septa between the dental alveoli and a promaxillary foramen that is visible in lateral view.

Conclusions/Significance

This is the first report of a North American troodontid from the Lower Cretaceous. It therefore contributes to a fuller understanding of troodontid biogeography through time. It also adds to the known dinosaurian fauna of the Cedar Mountain Formation.     

Lower limits of ornithischian dinosaur body size inferred from a new Upper Jurassic heterodontosaurid from North America

The extremes of dinosaur body size have long fascinated scientists. The smallest (<1 m length) known dinosaurs are carnivorous saurischian theropods, and similarly diminutive herbivorous or omnivorous ornithischians (the other major group of dinosaurs) are unknown. We report a new ornithischian dinosaur, Fruitadens haagarorum, from the Late Jurassic of western North America that rivals the smallest theropods in size. The largest specimens of Fruitadens represent young adults in their fifth year of development and are estimated at just 65–75 cm in total body length and 0.5–0.75 kg body mass. They are thus the smallest known ornithischians. Fruitadens is a late-surviving member of the basal dinosaur clade Heterodontosauridae, and is the first member of this clade to be described from North America. The craniodental anatomy and diminutive body size of Fruitadens suggest that this taxon was an ecological generalist with an omnivorous diet, thus providing new insights into morphological and palaeoecological diversity within Dinosauria. Late-surviving (Late Jurassic and Early Cretaceous) heterodontosaurids are smaller and less ecologically specialized than Early (Late Triassic and Early Jurassic) heterodontosaurids, and this ecological generalization may account in part for the remarkable 100-million-year-long longevity of the clade.     

A new species and new records of Cercophora from Argentina

Three species of Cercophora were found during a survey of the biodiversity of microfungi in northwest Argentina. Cercophora argentina possesses a unique combination of morphological characters and is described as a new species, while C. costaricensis and C. solaris are reported as new records for Argentina. Other species of Cercophora known from this region include C. natalita and C. coprogena, which is fully illustrated for the first time and determined herein to be a synonym of C. californica. All other species are described and illustrated.     

The first record of a dinosaur from Bulgaria

Mateus, O., Dyke, G.J., Motchurova-Dekova, N., Kamenov, G.D. & Ivanov, P. 2010: The first record of a dinosaur from Bulgaria. Lethaia, Vol. 43, pp. 88–94.
A portion of a left humerus from the Upper Maastrichtian of Vratsa district (NW Bulgaria) is shown to be from a non-avian theropod dinosaur: this is the first record of a dinosaur from Bulgaria. We describe this bone, suggest that it most likely pertains to an ornithomimosaur, and discuss the fossil record of other similar taxa of Late Cretaceous age that have been reported from Europe. To investigate the taphonomy of this fossil, rare earth element (REE) analysis is combined with strontium (Sr) isotope data to confirm that this Bulgarian dinosaur bone was initially fossilized in a terrestrial environment, then later re-worked into late Maastrichtian marine sediments. □ Bulgaria , Dinosauria , Late Cretaceous , Ornithomimosauria , rare earth elements , Sr isotopes , taphonomy , Theropoda .