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1.
Abstract:  The lectotype of the Middle Jurassic theropod dinosaur Megalosaurus bucklandii , a right dentary, can be diagnosed on the basis of two unique characters: a longitudinal groove on the ventral part of the lateral surface of the dentary and a slit-like anterior Meckelian foramen. This taxon, the first dinosaur to be scientifically described, is therefore valid. Currently, however, no further material can be referred to this species with any certainty. Megalosaurus bucklandii occupies an uncertain systematic position but is not an abelisaurid or coelophysoid. Additionally, it does not possess the diagnostic dentary characters that are present in all known spinosauroids. Owing to this uncertainty, use of the family Megalosauridae should be discontinued until such time as its systematic position becomes clearer.  相似文献   

2.
Abstract:  The assemblage of large-bodied theropod remains from the Taynton Limestone Formation (middle Bathonian) of Stonesfield, Oxfordshire and the Chipping Norton Limestone Formation (lowest Bathonian) of New Park Quarry, Gloucestershire, UK is interpreted as monospecific. An assessment of morphological variation in theropod fossils from these localities reveals no taxonomically-significant variation among remains representing large-bodied individuals. Previous observations of anatomical variation among femora, ilia and scapulocoracoids are attributed to postmortem damage and deformation. Referral of all such material to the first named dinosaur taxon, Megalosaurus bucklandii Mantell, is therefore justified. ' Iliosuchus incognitus ' lacks autapomorphies and is a nomen dubium . However, other remains of small-bodied theropods from Stonesfield indicate a minimum of two small-bodied taxa that are distinct from M. bucklandii.  相似文献   

3.
In comparison to pre-1980 records of nonavian dinosaur remains from the Maastrichtian type strata, material collected during the past 20 years is both fairly common and diverse, consisting mostly of isolated cranial and post-cranial remains of hadrosaurids. With the exception of the type specimen of Megalosaurus bredai Seeley, a fragmentary right femur, no theropod material is represented in collections screened by us. In the present contribution, specimens recognised in various collections subsequent to our last tabulation (1999) are illustrated and briefly discussed. Although we are fully aware that the material is too limited to draw meaningful conclusions from, the specimens are here tied-in with a preliminary sequence-stratigraphic interpretation of the type Maastrichtian, which is currently being refined by strontium-isotope studies of coleoid cephalopods. To cite this article: J.W.M. Jagt, E.W.A. Mulder, A.S. Schulp, R.W. Dortangs, R.H.B. Fraaije, C. R. Palevol 2 (2003) 67–76.  相似文献   

4.
A tetradactyl pes impression and tridactyl manus impression are described as the type specimen of Hatcherichnus sanjuanensis ichnogen. et ichnosp. nov., a probable large crocodilian ichnite from the Salt Wash Member of the Upper Jurassic Morrison Formation in eastern Utah. A similar pes track from the Morrison Formation at Garden Park, Colorado, may also belong to this ichnogenus. The type specimen from Utah consists of plaster replicas of natural casts of a left pes impression and a left manus impression. Associated with the type specimen were possible tail and body drag impressions. The tracks do not appear to be part of a walking trackway and may be swim tracks associated with an animal in shallow water. The tracks occur at a visible contact between slightly fining‐upward channel sandstone units.  相似文献   

5.
In a recent article, Alex Levine raises a paradox. It appears that, given some relatively uncontroversial premises about how a species term comes to refer to its species, a type specimen belongs necessarily and contingently to its species. According to Levine, this problem arises if species are individuals rather than natural kinds. I argue that the problem can be generalized: the problem also arises if species are kinds and type specimens are paradigmatic members used to baptize names for species. Indeed, the same problem arises with respect to kinds like gold and the samples used to ground names for them. After arguing that the paradox arises whether or not species are individuals, I attempt to show how the paradox can be resolved. Levine's argument that a type specimen belongs necessarily to its species is specious. The appeal of the argument stems from a failure to distinguish between two different modal statements concerning type specimens, one de dicto and the other de re. Type specimens belong contingently to their respective species. Even so, they can be known a priori to belong to them: hence, that a particular type specimen belongs to its species is an example of contingent a priori knowledge.  相似文献   

6.
A 6 m long specimen of Lepidodendron aculeatum Sternberg with attached leaves is described. The preserved portion of this axis gradually tapers from 38 cm wide at the lower end to 33.5 cm at the top. Ligule pit casts are present immediately above the leaf scars; they are similar to those of Lower Carboniferous lycophytes Angarodendron, Eskdalia, Tomiodendron, Ursodendron, and Meyenodendron and the Upper Carboniferous Bothrodendron. No such casts have beeen reported previously from Lepidodendron, although ligule pit cuticles have been prepared from Ulodendron, Lepidodendron, and Lepidophloios. This specimen is also unusual in that leaves are attached to the large stem. The specimen consists of external and internal molds, details of which show that the stem increased in width during burial and compression and prior to fossilization. The width of the specimen does not equal the original diameter of the stem but more closely corresponds to one half the circumference of the axis. This flattened log provides further details of overall Lepidodendron morphology and an insight into fossilization processes.  相似文献   

7.
The vertical distribution of culturable anoxygenic phototrophic bacteria was investigated at five sites at or near the Juan de Fuca Ridge in the Pacific Ocean. Twelve similar strains of obligately aerobic phototrophic bacteria were isolated in pure culture, from depths ranging from 500 to 2,379 m below the surface. These strains appear morphologically, physiologically, biochemically, and phylogenetically similar to Citromicrobium bathyomarinum strain JF-1, a bacterium previously isolated from hydrothermal vent plume waters. Only one aerobic phototrophic strain was isolated from surface waters. This strain is morphologically and physiologically distinct from the strains isolated at deeper sampling locations, and phylogenetic analysis indicates that it is most closely related to the genus Erythrobacter. Phototrophs were cultivated from three water casts taken above vents but not from two casts taken away from active vent sites. No culturable anaerobic anoxygenic phototrophs were detected. The photosynthetic apparatus was investigated in strain JF-1 and contains light-harvesting I and reaction center complexes, which are functional under aerobic conditions.  相似文献   

8.
The department of Antioquia, Colombia, lies in the northwestern corner of South America and provides a biogeographical link among divergent faunas, including Caribbean, Andean, Pacific and Amazonian. Information about the distribution of biodiversity in this area is of relevance for academic, practical and social purposes. This data paper describes the dataset containing all bird specimens deposited in the Colección de Ciencias Naturales del Museo Universitario de la Universidad de Antioquia (MUA). We curated all the information associated with the bird specimens, including the georeferences and taxonomy, and published the database through the Global Biodiversity Information Facility network. During this process we checked the species identification and existing georeferences and completed the information when possible. The collection holds 663 bird specimens collected between 1940 and 2011. Even though most specimens are from Antioquia (70%), the collection includes material from several other departments and one specimen from the United States. The collection holds specimens from three endemic and endangered species (Coeligena orina, Diglossa gloriossisima, and Hypopirrhus pyrohipogaster), and includes localities poorly represented in other collections. The information contained in the collection has been used for biodiversity modeling, conservation planning and management, and we expect to further facilitate these activities by making it publicly available.  相似文献   

9.
Using an independent method of direct tape-arc measurements on six chimpanzee brain casts, it is shown that Falk's (1980, 1983) claims regarding an anterior pongidlike placement of a lunate sulcus on the Taung specimen remain unconfirmed. Thus Holloway's (1981) stereoplotting method of testing Falk's hypothesis is independently confirmed, using the actual specimens rather than photographs of them. Falk's (1980) placement of a lunate sulcus falls at least 2.5 standard deviations anterior to a position expected on the basis of a Pan location.  相似文献   

10.
2013年9月在湖北省建始县采集到的2只务川臭蛙 (Odorrana wuchuanensis)标本,为湖北省新纪录。该记录使务川臭蛙的分布区由大娄山脉东段,沿武陵山脉延展至湖北建始县。因此,建议将其濒危等级调低至濒危(Endangered, 缩写为EN)。与模式标本比较,建始县雌蛙标本头体长99.6 mm,远大于模式标本雌蛙的最大记录;成年雄蛙62.8 mm,亦小于模式标本的最小记录;建始雌蛙体侧背皮肤亦有淡色小刺粒,因此,该特征不属于第二性征。  相似文献   

11.
Fresh, first morning specimens of urine from 22 consecutive patients were examined by quantitative microscopy on the morning of renal biopsy; the renal biopsy samples were evaluated "blindly." Five patients showed no abnormality in the biopsy samples but eight had minimal, one mild, six moderate, and two severe histological changes. Comparison of the results of quantitative microscopy of urine with the presence or absence of histological evidence of disease showed that sensitivity was 88%, specificity 83%, accuracy 86%, positive predictive value 93%, and negative predictive value 71%. When combined with microscopy of a second urine specimen these values were 100%, 50%, 87%, 85%, and 100% respectively. There was a significant relation between number of casts and severity of the histological changes (p less than 0.01). Comparison of renal functional abnormalities with histological findings gave values of 64%, 100%, 73%, 100%, and 50% respectively. It is concluded that quantitative microscopy of the first morning specimen of urine is a sensitive test with high predictive value for the presence or absence of renal disease. If no casts are detected in two early morning specimens the likelihood of finding anything more than minimal changes in a biopsy sample is virtually zero.  相似文献   

12.
Our understanding of early metriorhynchid evolution, the highly specialised pelagic clade of Mesozoic crocodylomorphs, is hampered by the paucity of basal metriorhynchoids and how poorly preserved most of these fossils are. This means the transition from a ‘gharial-like’ body-plan to a ‘pseudo-dolphin-like’ one, which characterises metriorhynchoid evolution, is still poorly understood. Herein the Middle Jurassic taxon Teleidosaurus calvadosii (J.A. Eudes-Deslongchamps, 1866) is re-evaluated. The holotype of T. calvadosii was destroyed during World War Two, as were all referred specimens. All that survived are plaster casts of the holotype. However, a recently discovered specimen from the middle Bathonian of Ecouché, Normandy, France is herein referred to T. calvadosii. This specimen preserves the antorbital region, an incomplete mandible and one cervical vertebra. This specimen is designated as neotype of T. calvadosii. The new specimen allows to re-evaluate the anatomy of T. calvadosii, in particular the antorbital fenestra, which has been misunderstood. Moreover, a comparison is made between the French Middle Jurassic metriorhynchoids Teleidosaurus and Eoneustes. Both genera appear as valid and E. bathonicus is considered to be a nomen dubium.  相似文献   

13.
<正> In the present paper a new caprine, Sinocapra minor gen. et sp. nov. is erected on the basis of several horn cores. The type specimen was collected by the Sino-American Palaeontology Expedition from the Upper Pliocene, Mazegou Formation, of Yunzhu Subbasin, Yushe Basin, Shansi province in 1988. All the other ones referred to the new genus were described and identified by Teilhard de Chardin and Trassaert (1938, p. 53, fig. 46) as Antilope gen. et sp. indet. They also came from Zhaozhuang, Yunzhu Subbasin and it is likely that they might be gathered from the same Formation as the type specimen judging by the yellow sandy clay filling into the horn cores. Magnetostratigraphic studies by Prof. N. Opdyke of the Yunzhu Subbasin indicates that this stratigraphic interval only includes the Gauss one, approximately 3.4 to 2.47 Ma. Accounts of the biostratigraphy and dating of Yunzhu Subbasin are giyen by Dr. R. H. Tedford and Dr. Z. Qiu in another paper.  相似文献   

14.
《Comptes Rendus Palevol》2019,18(3):390-406
The historian, archaeologist, and naturalist Charles de Gerville (1769–1853) reported as early as January 1816 the presence of fossil bones in the quarries of the region of Valognes, in the department of Manche. These quarries exploited the “Calcaire de Valognes” and the underlying “Argiles et Calcaires d’Huberville”, both formations dated as Lower Hettangian (Lower Jurassic). De Gerville communicated to Jacques-Louis-Marin Defrance a watercolour drawing of one of these fossil bones, discovered in July 1820, in which it is possible to recognize a plesiosaur femur. This femur, as well as a fragment of rib and three vertebrae of Plesiosauria from de Gerville's collection, was then figured in a publication by Arcisse de Caumont, in 1825. The plesiosaur femur was later acquired by Pierre Tesson of Caen, who owned one of the most important collections of fossils in Normandy. The Tesson collection was later purchased in 1857 by the British Museum (now The Natural History Museum, London), where the femur has been rediscovered. This specimen is the first known plesiosaur specimen ever discovered in the Lower Jurassic of France, before the genus Plesiosaurus was established upon material from the Lias of southwestern England. One of the vertebrae figured by de Caumont has been rediscovered in the “Muséum Emmanuel-Liais” (Cherbourg-en-Cotentin), which had acquired part of de Gerville's collection. The interpretation of the “fossil bones of Valognes” by Georges Cuvier, Henri Marie Ducrotay de Blainville, Arcisse de Caumont, Jacques-Amand Eudes-Deslongchamps and Constant Duméril is revealed through unpublished documents.  相似文献   

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17.
The record of theropod dinosaurs in Brazil is very scarce. One of the most promising lithostratigraphic units for those reptiles is the Bauru Group. The dinosaur remains found in this unit are mainly those of sauropods, while theropods are represented mostly by teeth. Here we describe a right scapula (housed at the Earth Science Museum of the Departamento Nacional de Produção Mineral/Rio de Janeiro) that is the first theropod scapula reported from the Cretaceous of Brazil and only the second osteological evidence of the Tetanurae from the Bauru Group. The specimen was recovered from the outskirts of Peirópolis, in Minas Gerais State. Comparisons with other theropod dinosaurs are limited, but the overall morphology of the new specimen indicates that it is neither a member of the Abelisauridae nor a member of the Avialae. It also differs from more basal members of the Theropoda, but its overall shape is consistent with several derived members of the Tetanurae, likely a non-avialan maniraptoran. Despite the lack of precision in its taxonomic position, the new specimen confirms the presence of non-avialan Maniraptora in the Bauru Group.  相似文献   

18.
19.
Epidermal growth factor receptor (EGFR) protein tyrosine kinases (PTKs) are attractive targets for anti-tumor drug design. Although thousands of their ligands have been studied as potential inhibitors against PTKs, there is no QSAR study that covers different kinds of inhibitors with observable structural diversity. However, by using this approach, we could mine far more useful information. Hence in order to better understand the binding model and the relationship between the physicochemical properties and the inhibitory activities of different kind of various inhibitors, molecular docking and 3D-QSAR, viz. CoMFA and CoMSIA, were combined to study 124 reported inhibitors with different scaffolds. Based on the docked binding conformations, highly reliable and predictive 3D-QSAR models were derived, which reveal how steric, electrostatic, and hydrophobic interactions contribute to inhibitors' bioactivities. This result also demonstrates that it is possible to include different kinds of inhibitors with observable structural diversity into one 3D-QSAR study. Therefore, this study not only casts light on binding mechanism between EGFR and its inhibitors, but also provides new hints for de novo design of new EGFR inhibitors with observable structural diversity.  相似文献   

20.
Inclusive fitness theory was not originally designed to explain the major transitions in evolution, but there is a growing consensus that it has the resources to do so. My aim in this paper is to highlight, in a constructive spirit, the puzzles and challenges that remain. I first consider the distinctive aspects of the cooperative interactions we see within the most complex social groups in nature: multicellular organisms and eusocial insect colonies. I then focus on one aspect in particular: the extreme redundancy these societies exhibit. I argue that extreme redundancy poses a distinctive explanatory puzzle for inclusive fitness theory, and I offer a potential solution which casts coercion as the key enabler. I suggest that the general moral to draw from the case is one of guarded optimism: while inclusive fitness is a powerful tool for understanding evolutionary transitions, it must be integrated within a broader framework that recognizes the distinctive problems such transitions present and the distinctive mechanisms by which these problems may be overcome.  相似文献   

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