57 research outputs found
Variation, variability, and the origin of the avian endocranium:Insights from the anatomy of alioramus altai (theropoda: Tyrannosauroidea)
The internal braincase anatomy of the holotype of Alioramus altai, a relatively small-bodied tyrannosauroid from the Late Cretaceous of Mongolia, was studied using high-resolution computed tomography. A number of derived characters strengthen the diagnosis of this taxon as both a tyrannosauroid and a unique, new species (e.g., endocranial position of the gasserian ganglion, internal ramification of the facial nerve). Also present are features intermediate between the basal theropod and avialan conditions that optimize as the ancestral condition for Coelurosauria--a diverse group of derived theropods that includes modern birds. The expression of several primitive theropod features as derived character states within Tyrannosauroidea establishes previously unrecognized evolutionary complexity and morphological plasticity at the base of Coelurosauria. It also demonstrates the critical role heterochrony may have played in driving patterns of endocranial variability within the group and potentially reveals stages in the evolution of neuroanatomical development that could not be inferred based solely on developmental observations of the major archosaurian crown clades. We discuss the integration of paleontology with variability studies, especially as applied to the nature of morphological transformations along the phylogenetically long branches that tend to separate the crown clades of major vertebrate groups
A New Troodontid Theropod, Talos sampsoni gen. et sp. nov., from the Upper Cretaceous Western Interior Basin of North America
Troodontids are a predominantly small-bodied group of feathered theropod dinosaurs notable for their close evolutionary relationship with Avialae. Despite a diverse Asian representation with remarkable growth in recent years, the North American record of the clade remains poor, with only one controversial species--Troodon formosus--presently known from substantial skeletal remains.Here we report a gracile new troodontid theropod--Talos sampsoni gen. et sp. nov.--from the Upper Cretaceous Kaiparowits Formation, Utah, USA, representing one of the most complete troodontid skeletons described from North America to date. Histological assessment of the holotype specimen indicates that the adult body size of Talos was notably smaller than that of the contemporary genus Troodon. Phylogenetic analysis recovers Talos as a member of a derived, latest Cretaceous subclade, minimally containing Troodon, Saurornithoides, and Zanabazar. MicroCT scans reveal extreme pathological remodeling on pedal phalanx II-1 of the holotype specimen likely resulting from physical trauma and subsequent infectious processes.Talos sampsoni adds to the singularity of the Kaiparowits Formation dinosaur fauna, which is represented by at least 10 previously unrecognized species including the recently named ceratopsids Utahceratops and Kosmoceratops, the hadrosaurine Gryposaurus monumentensis, the tyrannosaurid Teratophoneus, and the oviraptorosaurian Hagryphus. The presence of a distinct troodontid taxon in the Kaiparowits Formation supports the hypothesis that late Campanian dinosaurs of the Western Interior Basin exhibited restricted geographic ranges and suggests that the taxonomic diversity of Late Cretaceous troodontids from North America is currently underestimated. An apparent traumatic injury to the foot of Talos with evidence of subsequent healing sheds new light on the paleobiology of deinonychosaurians by bolstering functional interpretations of prey grappling and/or intraspecific combat for the second pedal digit, and supporting trackway evidence indicating a minimal role in weight bearing
The Osteology of the Basal Archosauromorph Tasmaniosaurus triassicus from the Lower Triassic of Tasmania, Australia
Proterosuchidae are the most taxonomically diverse archosauromorph reptiles sampled in the immediate aftermath of the Permo-Triassic mass extinction and represent the earliest radiation of Archosauriformes (archosaurs and closely related species). Proterosuchids are potentially represented by approximately 15 nominal species collected from South Africa, China, Russia, Australia and India, but the taxonomic content of the group is currently in a state of flux because of the poor anatomic and systematic information available for several of its putative members. Here, the putative proterosuchid Tasmaniosaurus triassicus from the Lower Triassic of Hobart, Tasmania (Australia),is redescribed. The holotype and currently only known specimen includes cranial and postcranial remains and the revision of this material sheds new light on the anatomy of the animal, including new data on the cranial endocast. Several bones are re-identified or reinterpreted, contrasting with the descriptions of previous authors. The new information provided here shows that Tasmaniosaurus closely resembles the South African proterosuchid Proterosuchus, but it differed in the presence of, for example, a slightly downturned premaxilla, a shorter anterior process of maxilla, and a diamond-shaped anterior end of interclavicle. Previous claims for the presence of gut contents in the holotype of Tasmaniosaurus are considered ambiguous. The description of the cranial endocast of Tasmaniosaurus provides for the first time information about the anatomy of this region in proterosuchids. The cranial endocast preserves possibly part of the vomero-nasal (= Jacobson's) system laterally to the olfactory bulbs. Previous claims of the absence of the vomero-nasal organs in archosaurs, which is suggested by the extant phylogenetic bracket, are questioned because its absence in both clades of extant archosaurs seems to be directly related with the independent acquisition of a non-ground living mode of life
Uso de ácido ascórbico e cloreto de cálcio na qualidade de repolho minimamente processado
The objective of this trial was to evaluate the effect of ascorbic acid (AA) and calcium chloride (CaCl2) applied by immersion at temperatures of 20 and 40 degrees C on the physicochemical and sensory characteristics of minimally processed cabbage, stored under refrigeration. Cabbages were processed in an industrial food processing equipment to be cut in slices with thickness of 3 mm. Slices were immersed in sodium hypochlorite (50 ppm) during 5 minutes for sanitization. After, the following treatments were carried out T1= control (immersion in water during 5 minutes at 20 degrees C); T2= immersion in 1% AA solution, during 5 minutes at 20 degrees C; T3= immersion in 2% AA solution, during 5 minutes at 20 degrees C; T4= immersion in 1% CaCl2 solution during 5 minutes at 20 degrees C; T5= immersion in 2% CaCl2 solution during 5 minutes at 20 degrees C, T6= immersion in 1% CaCl2 solution during 5 minutes at 40 degrees C; and T7= immersion in 2% CaCl2 solution during 5 minutes at 40 degrees C; with four replications each one. After application of treatments, cabbage was centrifuged during one minute, wrapped with polyvinyl chloride, 20 mu m, in trays of expanded polystyrene and maintained in refrigerated environment, at 6 +/- 1 degrees C and 85-90% of relative humidity, during eight days. Little increasing was observed in pH and titratable acidity values and reduction in soluble solids during conservation period on all treatments. Treatment with AA did not differ from control for color and general appearance, while treatment with 2% CaCl2 at 20 degrees C maintained the best quality, with less intensity of browning, best general appearance and purchase intent and least strange odor at the end of evaluation period.O objetivo deste trabalho foi avaliar o efeito do ácido ascórbico (AA) e do cloreto de cálcio (CaCl2) aplicado em imersão nas temperaturas de 20 e 40ºC, sobre as características físico-químicas e sensoriais do repolho minimamente processado e mantido sob refrigeração. Os repolhos foram cortados em fatias com espessura de 3 mm. As fatias foram imersas em hipoclorito de sódio (50 ppm) por 5 minutos para higienização. Foram realizados os tratamentos T1= testemunha (imersão em água por 5 min a 20ºC); T2= imersão em solução contendo AA a 1%, por 5 min a 20ºC; T3= imersão em solução contendo AA a 2%, por 5 min a 20ºC; T4= imersão em solução contendo CaCl2 a 1%, por 5 min a 20oC; T5= imersão em solução contendo CaCl2 a 2%, por 5 min a 20oC; T6= imersão em solução contendo CaCl2 a 1%, por 5 min a 40oC; T7= imersão em solução contendo CaCl2 a 2%, por 5 min a 40oC, com quatro repetições cada. Os produtos foram centrifugados por 1 minuto, embalados em bandejas de poliestireno expandido, recobertos com policloreto de vinila de 20 µm e mantidos a 6±1oC e UR de 85-90%, por oito dias. Observou-se pequena elevação dos valores de pH e acidez titulável e diminuição nos teores de sólidos solúveis durante o período de conservação, independente do tratamento. O tratamento com AA não diferiu da testemunha quanto a cor e aparência geral, enquanto que o tratamento com CaCl2 2% a 20oC foi o que melhor manteve a qualidade, com menor escurecimento, as melhores notas para aparência geral e intenção de compra e menor odor estranho no final do período de conservaçãoUNESP FCA, Dept Hort, BR-18610307 Botucatu, SP, BrazilUNESP FCA, Dept Hort, BR-18610307 Botucatu, SP, Brazi
Opalescence in Australian-grown pecan kernels: Occurrence and causes
Opalescence is an unattractive browning of the interior of the pecan kernel compared to the white interior of normal kernels. The discoloration is due to the presence of free oil, resulting from decompartmentalization in the endosperm of opalescent,pecans. Using a subjective scoring system, approximately 70% of Australian-grown pecan kernels tested were found to exhibit opalescence to some degree. Evaluation of kernels for opalescence during the harvesting-processing chain showed that opalescence first becomes evident in kernels after mechanical cracking. Opalescent kernels were found to have lower levels of calcium and higher amounts of oil compared to nonoptalescent kernels. Differential scanning calorimetry showed that kernels do not freeze at -18 degreesC
Antimicrobial Efficacy of a Peroxyacetic/Octanoic Acid Mixture in Fresh-Cut-Vegetable Process Waters
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