734 results on '"Bell PR"'
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2. New theropod remains and implications for megaraptorid diversity in the Winton Formation (lower Upper Cretaceous), Queensland, Australia.
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White, MA, Bell, PR, Poropat, SF, Pentland, AH, Rigby, SL, Cook, AG, Sloan, T, Elliott, DA, White, MA, Bell, PR, Poropat, SF, Pentland, AH, Rigby, SL, Cook, AG, Sloan, T, and Elliott, DA
- Abstract
The holotype specimen of the megaraptorid Australovenator wintonensis, from the Upper Cretaceous Winton Formation (Rolling Downs Group, Eromanga Basin) of central Queensland, is the most complete non-avian theropod found in Australia to date. In fact, the holotype of A. wintonensis and isolated megaraptorid teeth (possibly referable to Australovenator) constitute the only theropod body fossils reported from the Winton Formation. Herein, we describe a new fragmentary megaraptorid specimen from the Winton Formation, found near the type locality of A. wintonensis. The new specimen comprises parts of two vertebrae, two metatarsals, a pedal phalanx and multiple unidentifiable bone fragments. Although the new megaraptorid specimen is poorly preserved, it includes the only megaraptorid vertebrae known from Queensland. The presence of pleurocoels and highly pneumatic caudal centra with camerate and camellate internal structures permit the assignment of these remains to Megaraptora gen. et sp. indet. A morphological comparison revealed that the distal end of metatarsal II and the partial pedal phalanx II-1 of the new specimen are morphologically divergent from Australovenator. This might indicate the presence of a second megaraptorid taxon in the Winton Formation, or possibly intraspecific variation.
- Published
- 2020
3. Oil Shale: Characterisation of Wastewaters
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Chemeca 82 (10th : 1982 : Sydney, N.S.W.), Bell, PR, Greenfield, PF, and Krol, AA
- Published
- 1982
4. The dentary of Australovenator wintonensis (Theropoda, Megaraptoridae); implications for megaraptorid dentition.
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White, MA, Bell, PR, Cook, AG, Poropat, SF, Elliott, DA, White, MA, Bell, PR, Cook, AG, Poropat, SF, and Elliott, DA
- Abstract
Megaraptorid theropods were an enigmatic group of medium-sized predatory dinosaurs, infamous for the hypertrophied claw on the first manual digit. Megaraptorid dentition is largely restricted to isolated teeth found in association with skeletal parts; however, the in situ maxillary dentition of Megaraptor was recently described. A newly discovered right dentary pertaining to the Australovenator holotype preserves in situ dentition, permitting unambiguous characterisation of the dentary tooth morphology. The new jaw is virtually complete, with an overall elongate, shallow profile, and fifteen visible in situ teeth at varying stages of eruption. In situ teeth confirm Australovenator exhibited modest pseudoheterodonty, recurved lateral teeth with a serrate distal carina and reduced mesial carina, similar to other megaraptorids. Australovenator also combines of figure-of-eight basal cross-section with a lanceolate shape due to the presence of labial and lingual depressions and the lingual twist of the distal carina. Computed tomography and three-dimensional imagery provided superior characterisation of the dentary morphology and enabled an accurate reconstruction to a pre-fossilised state. The newly established dental morphology also afforded re-evaluation of isolated theropod teeth discovered at the Australovenator holotype locality and from several additional Winton Formation localities. The isolated Winton teeth are qualitatively and quantitatively similar to the in situ dentary teeth of Australovenator, but are also morphometrically similar to Abelisauridae, Allosauridae, Coelophysoidea, Megalosauridae and basal Tyrannosauroidea. Qualitative characters, however, clearly distinguish the teeth of Australovenator and the isolated Winton teeth from all other theropods. Evidence from teeth suggests megaraptorids were the dominant predators in the Winton Formation, which contrasts with other penecontemporaneous Gondwanan ecosystems.
- Published
- 2015
5. Forearm Range of Motion in Australovenator wintonensis (Theropoda, Megaraptoridae).
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Carrier, D, White, MA, Bell, PR, Cook, AG, Barnes, DG, Tischler, TR, Bassam, BJ, Elliott, DA, Carrier, D, White, MA, Bell, PR, Cook, AG, Barnes, DG, Tischler, TR, Bassam, BJ, and Elliott, DA
- Abstract
The hypertrophied manual claws and modified manus of megaraptoran theropods represent an unusual morphological adaptation among carnivorous dinosaurs. The skeleton of Australovenator wintonensis from the Cenomanian of Australia is among the most complete of any megaraptorid. It presents the opportunity to examine the range of motion of its forearm and the function of its highly modified manus. This provides the basis for behavioural inferences, and comparison with other Gondwanan theropod groups. Digital models created from computed tomography scans of the holotype reveal a humerus range of motion that is much greater than Allosaurus, Acrocanthosaurus, Tyrannosaurus but similar to that of the dromaeosaurid Bambiraptor. During flexion, the radius was forced distally by the radial condyle of the humerus. This movement is here suggested as a mechanism that forced a medial movement of the wrist. The antebrachium possessed a range of motion that was close to dromaeosaurids; however, the unguals were capable of hyper-extension, in particular manual phalanx I-2, which is a primitive range of motion characteristic seen in allosaurids and Dilophosaurus. During flexion, digits I and II slightly converge and diverge when extended which is accentuated by hyperextension of the digits in particular the unguals. We envision that prey was dispatched by its hands and feet with manual phalanx I-2 playing a dominant role. The range of motion analysis neither confirms nor refutes current phylogenetic hypotheses with regards to the placement of Megaraptoridae; however, we note Australovenator possessed, not only a similar forearm range of motion to some maniraptorans and basal coelurosaurs, but also similarities with Tetanurans (Allosauroids and Dilophosaurus).
- Published
- 2015
6. ESVS guidelines. Invasive treatment for carotid stenosis: indications, techniques.
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Liapis, C, Bell, P, Mikhailidis, D, Sivenius, J, Nicolaides, A, Fernandes e. Fernandes, J, Biasi, G, Norgren, L, Froio, A, Lavitrano, M, Liapis, CD, Bell, PR, BIASI, GIORGIO MARIA, FROIO, ALBERTO, LAVITRANO, MARIALUISA, Liapis, C, Bell, P, Mikhailidis, D, Sivenius, J, Nicolaides, A, Fernandes e. Fernandes, J, Biasi, G, Norgren, L, Froio, A, Lavitrano, M, Liapis, CD, Bell, PR, BIASI, GIORGIO MARIA, FROIO, ALBERTO, and LAVITRANO, MARIALUISA
- Abstract
The European Society for Vascular Surgery brought together a group of experts in the field of carotid artery disease to produce updated guidelines for the invasive treatment of carotid disease. The recommendations were rated according to the level of evidence. Carotid endarterectomy (CEA) is recommended in symptomatic patients with >50% stenosis if the perioperative stroke/death rate is <6% [A], preferably within 2 weeks of the patient's last symptoms [A]. CEA is also recommended in asymptomatic men <75 years old with 70-99% stenosis if the perioperative stroke/death risk is <3% [A]. The benefit from CEA in asymptomatic women is significantly less than in men [A]. CEA should therefore be considered only in younger, fit women [A]. Carotid patch angioplasty is preferable to primary closure [A]. Aspirin at a dose of 75-325 mg daily and statins should be given before, during and following CEA. [A] Carotid artery stenting (CAS) should be performed only in high-risk for CEA patients, in high-volume centres with documented low peri-operative stroke and death rates or inside a randomized controlled trial [C]. CAS should be performed under dual antiplatelet treatment with aspirin and clopidogrel [A]. Carotid protection devices are probably of benefit [C]. © 2008 European Society for Vascular Surgery.
- Published
- 2009
7. Enhanced invasive properties exhibited by smooth muscle cells are associated with elevated production of MMP-2 in patients with aortic aneurysms
- Author
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Goodall, S, Porter, KE, Bell, PR, Thompson, MM, Goodall, S, Porter, KE, Bell, PR, and Thompson, MM
- Abstract
Background: abdominal aortic aneurysms (AAA) are associated with excessive vascular matrix remodelling. Recent findings suggest a systemic overproduction of matrix metalloproteinases-2 (MMP-2) by vascular smooth muscle cells (SMC) may be pivotal aetiologically. SMC migration is facilitated by MMP mediated proteolysis of the basement membrane and extracellular matrix. Our aim was to see if enhanced MMP-2 production by these SMC exhibit increased invasion, in an in vitro model of migration. Method: SMC were derived from inferior mesenteric vein (IMV) harvested from patients undergoing aneurysm repair (n = 6) or colectomy for diverticulosis (n = 6, control). Using a modified Boy den chamber chemotaxis was measured towards platelet derived growth factor (PDGF) and foetal calf serum (FCS) and invasion through a Matrigel layer. MMP-2 production was quantified by ELISA and gelatin zymography. Results: chemoattractant studies demonstrated no difference in the effect of PDGF or FCS between the two populations of SMC. However, invasive studies demonstrated a significant increase in the number of migrating SMC isolated from IMV of AAA patients. Analysis of culture media extracts revealed that this difference was associated with a significant increase in production of MMP-2. Conclusion: SMC derived from patients with AAA demonstrate increased invasive properties when compared to a control group. Increased migration appears to be due to overproduction of MMP-2. The enhanced migratory potential of these SMC may lead to extracellular matrix remodelling and subsequent medial disruption demonstrated in the aneurysmal aorta. These data further support evidence of the proteolytic role of MMP-2 in cell migration. © 2002 Elsevier Science Ltd. All rights reserved.
- Published
- 2002
8. The association between venous structural alterations and biomechanical weakness in patients with abdominal aortic aneurysms
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Goodall, S, Crowther, M, Bell, PR, Thompson, MM, Goodall, S, Crowther, M, Bell, PR, and Thompson, MM
- Abstract
Objective: Abdominal aortic aneurysms (AAAs) are associated with generalized arterial dilation, torturosity, and altered matrix composition, which suggests a generalized systemic weakness throughout the entire vasculature. The aim of this study was to determine whether this phenomenon was present in the venous tissue of patients with AAA. Methods: A segment of inferior mesenteric vein was harvested from patients who underwent aneurysm repair (n = 11) or colectomy for diverticulosis (n = 11; control). Matrix composition of the vessel was determined with stereology, and dimensions were measured with a computerized image analysis system. Stress-strain measurements were calculated with elongation of inferior mesenteric vein tissue with a tensile-testing machine. Results: Histologic examination results showed fragmentation of elastin fibers within the medial layer of venous tissue obtained from patients with AAA. The medial clastin content in tissue from patients with aneurysms was 19.4%, compared with 26.8% in the control group (P = .018). Mechanical test results revealed a significant reduction in the tensile strength from 2.885 MPa in the control group to 1.405 MPa in the AAA group (P = .007). This reduction corresponded with a significant reduction of 59% in the stiffness of the vessel, with the mean Young's modulus of elasticity in the AAA group being 2.72 MPa, compared with 5.361 MPa in the control group (P = .0005). Conclusion: Reduction in tensile strength and stiffness in venous tissue from patients with AAA was associated with disruption and reduction of the clastin content of the vein wall. These changes are analogous to those observed in the arterial aneurysmal wall and confirm the systemic nature of this disorder. Copyright © 2002 by The Society for Vascular Surgery and The American Association for Vascular Surgery.
- Published
- 2002
9. Impaired Endothelium-Dependent Relaxation in Critical Leg Ischaemi A
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Hillier, C, primary, Sayers, RD, additional, Watt, P, additional, Bell, PR, additional, and Thurston, H, additional
- Published
- 1994
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10. Microvessel Structure and Function in Critical Leg Ischaemia
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Hillier, C, primary, Sayers, RD, additional, Watt, P, additional, Bell, PR, additional, and Thurston, H, additional
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- 1994
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11. Matrix metalloproteinase-8 and -9 are increased at the site of abdominal aortic aneurysm rupture.
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Wilson WR, Anderton M, Schwalbe EC, Jones JL, Furness PN, Bell PR, and Thompson MM
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- 2006
12. Beneficial effects of clopidogrel combined with aspirin in reducing cerebral emboli in patients undergoing carotid endarterectomy.
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Payne DA, Jones CI, Hayes PD, Thompson MM, London NJ, Bell PR, Goodall AH, Naylor AR, Payne, David A, Jones, Chris I, Hayes, Paul D, Thompson, Matthew M, London, Nicholas J, Bell, Peter R, Goodall, Alison H, and Naylor, A Ross
- Published
- 2004
13. MIGRATION INHIBITION AND HOMOGRAFT REJECTION IN RATS
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Eidemiller Lr and Bell Pr
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Graft Rejection ,Immunity, Cellular ,Transplantation ,Time Factors ,business.industry ,Rats, Inbred Strains ,Skin Transplantation ,Thymus Gland ,Biology ,Rats ,Antigen-Antibody Reactions ,Homograft rejection ,Text mining ,Transplantation Immunology ,Cell Migration Inhibition ,Immunology ,Animals ,Heart Transplantation ,Transplantation, Homologous ,Migration inhibition ,Lymph Nodes ,Antigens ,business ,Spleen - Published
- 1972
14. ESVS Guidelines. Invasive Treatment for Carotid Stenosis: Indications, Techniques
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Liapis, CD, Bell, PR, Mikhailidis, D, Sivenius, J, Nicolaides, A, Fernandes e. Fernandes, J, Norgren, L, BIASI, GIORGIO MARIA, FROIO, ALBERTO, LAVITRANO, MARIALUISA, Liapis, C, Bell, P, Mikhailidis, D, Sivenius, J, Nicolaides, A, Fernandes e. Fernandes, J, Biasi, G, Norgren, L, Froio, A, and Lavitrano, M
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carotid stenosis, endarterectomy, stenting, indication ,medicine.medical_specialty ,Stenting ,medicine.medical_treatment ,Myocardial Infarction ,Carotid endarterectomy ,Comorbidity ,Coronary Artery Disease ,Endarterectomy ,Guidelines ,Asymptomatic ,Angioplasty ,Internal medicine ,Carotid artery disease ,MED/22 - CHIRURGIA VASCOLARE ,Carotid stenosis ,Medicine ,Humans ,cardiovascular diseases ,Coronary Artery Bypass ,Stroke ,Societies, Medical ,Medicine(all) ,Clinical Trials as Topic ,business.industry ,Patient Selection ,medicine.disease ,Surgery ,Europe ,Treatment ,Stenosis ,Ischemic Attack, Transient ,Cardiology ,Platelet aggregation inhibitor ,Stents ,medicine.symptom ,Hydroxymethylglutaryl-CoA Reductase Inhibitors ,Cardiology and Cardiovascular Medicine ,business ,Vascular Surgical Procedures ,Platelet Aggregation Inhibitors - Abstract
The European Society for Vascular Surgery brought together a group of experts in the field of carotid artery disease to produce updated guidelines for the invasive treatment of carotid disease. The recommendations were rated according to the level of evidence. Carotid endarterectomy (CEA) is recommended in symptomatic patients with >50% stenosis if the perioperative stroke/death rate is
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15. Experimental allergic thyroiditis in rats: suppression by heterologous (rabbit) anti-lymphocyte sera to lymph node, thymic and splenic lymphocytes.
- Author
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Macsween, RN, Ono, K, Bell, PR, Thomason, CM, Starzl, TE, Macsween, RN, Ono, K, Bell, PR, Thomason, CM, and Starzl, TE
- Published
- 1970
16. Conservation of the liver.
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Brettschneider, L, Bell, PR, Martin, AJ, Tarr, JS, Taylor, PD, Starzl, TE, Brettschneider, L, Bell, PR, Martin, AJ, Tarr, JS, Taylor, PD, and Starzl, TE
- Published
- 1969
17. Pressure fluctuations in vacuum systems
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Bell, PR, primary and Kelley, GG, additional
- Published
- 1966
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18. Organelle in der Eizelle vonDryopteris filix-mas (L.) Schott
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Bell Pr
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medicine.anatomical_structure ,Botany ,medicine ,General Medicine ,Biology ,Oocyte ,biology.organism_classification ,Dryopteris ,Ecology, Evolution, Behavior and Systematics - Published
- 1966
19. Delayed presentation following accidental inhalation of a pushpin.
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Bell PR, Curran P, Bell, P R, and Curran, P
- Abstract
A previously fit and well 18-year-old woman presented to the accident and emergency department following referral by her general practitioner with a provisional diagnosis of appendicitis. The history obtained from the patient revealed the presence of a bitemporal headache with associated neck stiffness, photophobia and vomiting for approximately 1.5 weeks. The patient complained of abdominal pain localised to her right iliac fossa and anorexia for approximately 1 week. She also noted the presence of a cough productive of green sputum for 3 weeks. A chest radiograph was obtained which showed a large area of consolidation in the right lower lobe consistent with infection and a linear density in keeping with a metallic foreign body. Following review of the chest radiograph, the patient was interviewed further and recalled having inhaled a pushpin approximately 1 year before her presentation. Aspiration of foreign bodies is relatively common in children and is often associated with delayed diagnosis and high morbidity. To prevent delayed diagnosis, characteristic symptoms and clinical and radiological signs of foreign body aspiration should be checked in all suspected cases and a low index of suspicion for ordering additional imaging or using bronchoscopy for diagnostic purposes should be employed. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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20. The needle catcher--a safer way to suture.
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Bell PR, McNicholl BP, Bell, P R, and McNicholl, B P
- Abstract
The needle catcher is a novel surgical instrument which has been developed in Belfast in conjunction with Queen's University Belfast that aims to reduce suture needle exposure and increase operator safety during suturing. The instrument was used to close wounds in 20 patients presenting to A&E in the Royal Group of Hospitals and to the plastic surgery service in the Ulster Hospital. This letter includes a technical description of the instrument, evaluation of needle exposure, comments from users, evaluation of the needle catcher and a discussion on the need for additional protection for medical staff in surgical based specialties where there is frequent exposure to blood, open wounds and sharps. [ABSTRACT FROM AUTHOR]
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- 2009
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21. Medical angiologists. Britain needs them.
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Lowe GD, Belch J, Bell PR, Smith PD, Dormandy JA, Fowkes FG, Gaines PA, Housley F, Jayson MI, and Nicolaides A
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- 1993
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22. Carotid and Vertebral Artery Transluminal Angioplasty Study.
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Naylor, A R., London, NJM., Bell, PR F., London, N J, and Bell, P R
- Subjects
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CLINICAL trials , *EXPERIMENTAL design , *TRANSLUMINAL angioplasty , *PATIENT selection , *CAROTID endarterectomy , *THERAPEUTICS ,CAROTID artery stenosis - Published
- 1997
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23. Exceptional preservation and foot structure reveal ecological transitions and lifestyles of early theropod flyers.
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Pittman M, Bell PR, Miller CV, Enriquez NJ, Wang X, Zheng X, Tsang LR, Tse YT, Landes M, and Kaye TG
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- Animals, Biological Evolution, Fossils, Adaptation, Physiological, Phylogeny, Musculoskeletal System anatomy & histology, Dinosaurs anatomy & histology
- Abstract
Morphology of keratinised toe pads and foot scales, hinging of foot joints and claw shape and size all inform the grasping ability, cursoriality and feeding mode of living birds. Presented here is morphological evidence from the fossil feet of early theropod flyers. Foot soft tissues and joint articulations are qualitatively assessed using laser-stimulated fluorescence. Pedal claw shape and size are quantitatively analysed using traditional morphometrics. We interpret these foot data among existing evidence to better understand the evolutionary ecology of early theropod flyers. Jurassic flyers like Anchiornis and Archaeopteryx show adaptations suggestive of relatively ground-dwelling lifestyles. Early Cretaceous flyers then diversify into more aerial lifestyles, including generalists like Confuciusornis and specialists like the climbing Fortunguavis. Some early birds, like the Late Jurassic Berlin Archaeopteryx and Early Cretaceous Sapeornis, show complex ecologies seemingly unique among sampled modern birds. As a non-bird flyer, finding affinities of Microraptor to a more specialised raptorial lifestyle is unexpected. Its hawk-like characteristics are rare among known theropod flyers of the time suggesting that some non-bird flyers perform specialised roles filled by birds today. We demonstrate diverse ecological profiles among early theropod flyers, changing as flight developed, and some non-bird flyers have more complex ecological roles., (© 2022. The Author(s).)
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- 2022
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24. The exquisitely preserved integument of Psittacosaurus and the scaly skin of ceratopsian dinosaurs.
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Bell PR, Hendrickx C, Pittman M, Kaye TG, and Mayr G
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- Animals, Fossils, Preservation, Biological, Skin, Carcinoma, Squamous Cell, Dinosaurs anatomy & histology
- Abstract
The Frankfurt specimen of the early-branching ceratopsian dinosaur Psittacosaurus is remarkable for the exquisite preservation of squamous (scaly) skin and other soft tissues that cover almost its entire body. New observations under Laser-Stimulated Fluorescence (LSF) reveal the complexity of the squamous skin of Psittacosaurus, including several unique features and details of newly detected and previously-described integumentary structures. Variations in the scaly skin are found to be strongly regionalized in Psittacosaurus. For example, feature scales consist of truncated cone-shaped scales on the shoulder, but form a longitudinal row of quadrangular scales on the tail. Re-examined through LSF, the cloaca of Psittacosaurus has a longitudinal opening, or vent; a condition that it shares only with crocodylians. This implies that the cloaca may have had crocodylian-like internal anatomy, including a single, ventrally-positioned copulatory organ. Combined with these new integumentary data, a comprehensive review of integument in ceratopsian dinosaurs reveals that scalation was generally conservative in ceratopsians and typically consisted of large subcircular-to-polygonal feature scales surrounded by a network of smaller non-overlapping polygonal basement scales. This study highlights the importance of combining exceptional specimens with modern imaging techniques, which are helping to redefine the perceived complexity of squamation in ceratopsians and other dinosaurs., (© 2022. The Author(s).)
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- 2022
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25. Oldest preserved umbilical scar reveals dinosaurs had 'belly buttons'.
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Bell PR, Hendrickx C, Pittman M, and Kaye TG
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- Animals, Biological Evolution, Birds, Cicatrix, Female, Fossils, Mammals, Placenta, Pregnancy, Umbilicus anatomy & histology, Dinosaurs anatomy & histology, Lizards anatomy & histology
- Abstract
Background: In egg-laying amniotes, the developing embryo is tethered to a number of the extraembryonic membranes including the yolk sac and allantois that deliver oxygen and nutrients and remove metabolic waste products throughout embryonic development. Prior to, or soon after hatching, these membranes detach from the animal leaving a temporary or permanent umbilical scar (umbilicus) equivalent to the navel or 'belly button' in some placental mammals, including humans. Although ubiquitous in modern mammals and reptiles (including birds), at least early in their ontogeny, the umbilicus has not been identified in any pre-Cenozoic amniote., Results: We report the oldest preserved umbilicus in a fossil amniote from a ~130-million-year-old early-branching ceratopsian dinosaur, Psittacosaurus. Under laser-stimulated fluorescence (LSF), the umbilicus is revealed as an elongate midline structure delimited by a row of paired scales on the abdomen. The relatively late ontogenetic stage (close to sexual maturity) estimated for the individual indicates that the umbilicus was probably retained throughout life., Conclusions: Unlike most extant reptiles and birds that lose this scar within days to weeks after hatching, the umbilicus of Psittacosaurus persisted at least until sexual maturity, similar to some lizards and crocodylians with which it shares the closest morphological resemblance. This discovery is the oldest record of an amniote umbilicus and the first in a non-avian dinosaur. However, given the variability of this structure in extant reptilian analogues, a persistent umbilical scar may not have been present in all non-avian dinosaurs., (© 2022. The Author(s).)
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- 2022
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26. Morphology and distribution of scales, dermal ossifications, and other non-feather integumentary structures in non-avialan theropod dinosaurs.
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Hendrickx C, Bell PR, Pittman M, Milner ARC, Cuesta E, O'Connor J, Loewen M, Currie PJ, Mateus O, Kaye TG, and Delcourt R
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- Animals, Biological Evolution, Birds, Feathers anatomy & histology, Fossils, Osteogenesis, Phylogeny, Animal Scales, Carcinoma, Squamous Cell, Dinosaurs anatomy & histology
- Abstract
Modern birds are typified by the presence of feathers, complex evolutionary innovations that were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that include crown Aves. Squamous or scaly reptilian-like skin is, however, considered the plesiomorphic condition for theropods and dinosaurs more broadly. Here, we review the morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications. The integumentary record of non-averostran theropods is limited to tracks, which ubiquitously show a covering of tiny reticulate scales on the plantar surface of the pes. This is consistent also with younger averostran body fossils, which confirm an arthral arrangement of the digital pads. Among averostrans, squamous skin is confirmed in Ceratosauria (Carnotaurus), Allosauroidea (Allosaurus, Concavenator, Lourinhanosaurus), Compsognathidae (Juravenator), and Tyrannosauroidea (Santanaraptor, Albertosaurus, Daspletosaurus, Gorgosaurus, Tarbosaurus, Tyrannosaurus), whereas dermal ossifications consisting of sagittate and mosaic osteoderms are restricted to Ceratosaurus. Naked, non-scale bearing skin is found in the contentious tetanuran Sciurumimus, ornithomimosaurians (Ornithomimus) and possibly tyrannosauroids (Santanaraptor), and also on the patagia of scansoriopterygids (Ambopteryx, Yi). Scales are surprisingly conservative among non-avialan theropods compared to some dinosaurian groups (e.g. hadrosaurids); however, the limited preservation of tegument on most specimens hinders further interrogation. Scale patterns vary among and/or within body regions in Carnotaurus, Concavenator and Juravenator, and include polarised, snake-like ventral scales on the tail of the latter two genera. Unusual but more uniformly distributed patterning also occurs in Tyrannosaurus, whereas feature scales are present only in Albertosaurus and Carnotaurus. Few theropods currently show compelling evidence for the co-occurrence of scales and feathers (e.g. Juravenator, Sinornithosaurus), although reticulate scales were probably retained on the mani and pedes of many theropods with a heavy plumage. Feathers and filamentous structures appear to have replaced widespread scaly integuments in maniraptorans. Theropod skin, and that of dinosaurs more broadly, remains a virtually untapped area of study and the appropriation of commonly used techniques in other palaeontological fields to the study of skin holds great promise for future insights into the biology, taphonomy and relationships of these extinct animals., (© 2022 Cambridge Philosophical Society.)
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- 2022
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27. Newly detected data from Haestasaurus and review of sauropod skin morphology suggests Early Jurassic origin of skin papillae.
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Pittman M, Enriquez NJ, Bell PR, Kaye TG, and Upchurch P
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- Animals, Epidermis, Skin, Dinosaurs anatomy & histology
- Abstract
Discovered in 1852, the scaly skin belonging to Haestasaurus becklesii was the first to be described in any non-avian dinosaur. Accordingly, it has played a crucial role in the reconstruction of sauropod integument and dinosaurs more broadly. Here, we reassess this historic specimen using Laser-Stimulated Fluorescence (LSF), revealing extensive, previously unknown regions of skin that augment prior interpretations of its integumentary morphology and taphonomy. Under white light, polygonal-subrounded, convex scales are visible on one side of the block ('side A'), but LSF reveals extensive smaller and more flattened scales, which are diagenetically fragmented, on the reverse block surface ('side B'). Contrary to the prior interpretation that the visible scales are the epidermal undersides, the presence of convex, intrascale papilliform textures on side A suggests that the external skin surface is exposed. We define intrascale papillae and provide a review of sauropod skin morphology, which clarifies that intrascale papillae are unique to and widespread across stem Neosauropoda, and likely have an evolutionary origin in the Early Jurassic. Intrascale papillae may ultimately have been integral to the evolution of gigantism in this charismatic clade., (© 2022. The Author(s).)
- Published
- 2022
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28. The dinosaur tracks of Tyrants Aisle: An Upper Cretaceous ichnofauna from Unit 4 of the Wapiti Formation (upper Campanian), Alberta, Canada.
- Author
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Enriquez NJ, Campione NE, White MA, Fanti F, Sissons RL, Sullivan C, Vavrek MJ, and Bell PR
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- Alberta, Animals, Dinosaurs anatomy & histology, Dinosaurs physiology, Fossils
- Abstract
The Wapiti Formation of northwest Alberta and northeast British Columbia, Canada, preserves an Upper Cretaceous terrestrial vertebrate fauna that is latitudinally situated between those documented further north in Alaska and those from southern Alberta and the contiguous U.S.A. Therefore, the Wapiti Formation is important for identifying broad patterns in vertebrate ecology, diversity, and distribution across Laramidia during the latest Cretaceous. Tracksites are especially useful as they provide a range of palaeoecological, palaeoenvironmental, and behavioural data that are complementary to the skeletal record. Here, we describe the Tyrants Aisle locality, the largest in-situ tracksite known from the Wapiti Formation. The site occurs in the lower part of Unit 4 of the formation (~72.5 Ma, upper Campanian), exposed along the southern bank of the Redwillow River. More than 100 tracks are documented across at least three distinct track-bearing layers, which were deposited on an alluvial floodplain. Hadrosaurid tracks are most abundant, and are referable to Hadrosauropodus based on track width exceeding track length, broad digits, and rounded or bilobed heel margins. We suggest the hadrosaurid trackmaker was Edmontosaurus regalis based on stratigraphic context. Tyrannosaurids, probable troodontids, possible ornithomimids, and possible azhdarchid pterosaurs represent minor but notable elements of the ichnofauna, as the latter is unknown from skeletal remains within the Wapiti Formation, and all others are poorly represented. Possible social behaviour is inferred for some of the hadrosaurid and small theropod-like trackmakers based on trackway alignment, suitable spacing and consistent preservation. On a broad taxonomic level (i.e., family or above), ichnofaunal compositions indicate that hadrosaurids were palaeoecologically dominant across Laramidia during the late Campanian within both high-and low-latitude deposits, although the role of depositional environment requires further testing., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2022
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29. Taphonomy and taxonomy of a juvenile lambeosaurine (Ornithischia: Hadrosauridae) bonebed from the late Campanian Wapiti Formation of northwestern Alberta, Canada.
- Author
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Holland B, Bell PR, Fanti F, Hamilton SM, Larson DW, Sissons R, Sullivan C, Vavrek MJ, Wang Y, and Campione NE
- Abstract
Hadrosaurid (duck-billed) dinosaur bonebeds are exceedingly prevalent in upper Cretaceous (Campanian-Maastrichtian) strata from the Midwest of North America (especially Alberta, Canada, and Montana, U.S.A) but are less frequently documented from more northern regions. The Wapiti Formation (Campanian-Maastrichtian) of northwestern Alberta is a largely untapped resource of terrestrial palaeontological information missing from southern Alberta due to the deposition of the marine Bearpaw Formation. In 2018, the Boreal Alberta Dinosaur Project rediscovered the Spring Creek Bonebed, which had been lost since 2002, along the northern bank of the Wapiti River, southwest of Grande Prairie. Earlier excavations and observations of the Spring Creek Bonebed suggested that the site yielded young hadrosaurines. Continued work in 2018 and 2019 recovered ~300 specimens that included a minimum of eight individuals, based on the number of right humeri. The morphology of several recovered cranial elements unequivocally supports lambeosaurine affinities, making the Spring Creek sample the first documented occurrence of lambeosaurines in the Wapiti Formation. The overall size range and histology of the bones found at the site indicate that these animals were uniformly late juveniles, suggesting that age segregation was a life history strategy among hadrosaurids. Given the considerable size attained by the Spring Creek lambeosaurines, they were probably segregated from the breeding population during nesting or caring for young, rather than due to different diet and locomotory requirements. Dynamic aspects of life history, such as age segregation, may well have contributed to the highly diverse and cosmopolitan nature of Late Cretaceous hadrosaurids., Competing Interests: The authors declare that they have no competing interests., (© 2021 Holland et al.)
- Published
- 2021
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30. Crocodile-like sensory scales in a Late Jurassic theropod dinosaur.
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Bell PR and Hendrickx C
- Subjects
- Alligators and Crocodiles physiology, Animals, Integumentary System anatomy & histology, Integumentary System physiology, Ultraviolet Rays, Biological Evolution, Dinosaurs anatomy & histology, Dinosaurs physiology, Epidermis anatomy & histology, Epidermis physiopathology, Fossils, Sense Organs physiology
- Abstract
Early in amniote evolution, epidermal scales evolved in stem reptiles as an efficient barrier against water loss and ultraviolet radiation, making them a key development in the transition to a fully terrestrial existence [1]. Accordingly, epidermal scales are not simple inert structures but highly-evolved organs suited to perform a broad suite of functions. Here, we provide new data on the epidermal complexity of a non-avian theropod, Juravenator starki, from the Torleite Formation (upper Kimmeridgian), Bavaria, Germany [2]. Although epidermal scales have been noted previously on the tail of Juravenator, we report a unique scale type with distinctive circular nodes that we identify as integumentary sense organs, analogous to those in modern crocodylians. The surprising presence of such structures suggests the tail had a sensory function, which is nevertheless congruent with the inferred ecology of Juravenator and the evolution of integumentary sense organs among archosaurs., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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31. Noasaurids are a component of the Australian 'mid'-Cretaceous theropod fauna.
- Author
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Birch SA, Smith ET, and Bell PR
- Subjects
- Animals, Australia, Biological Evolution, Classification, Phylogeography, Physiology, Comparative, Cervical Vertebrae anatomy & histology, Dinosaurs physiology
- Abstract
The diversity of Australia's theropod fauna from the 'mid'-Cretaceous (Albian-Cenomanian) is distinctly biased towards the medium-sized megaraptorids, despite the preponderance of abelisauroids in the younger but latitudinally equivalent Patagonian theropod fauna. Here, we present new evidence for the presence of ceratosaurian, and specifically abelisauroid, theropods from the Cenomanian Griman Creek Formation of Lightning Ridge, New South Wales. A partial cervical vertebra is described that bears a mediolaterally concave ventral surface of the centrum delimited by sharp ventrolateral ridges that contact the parapophyses. Among theropods, this feature has been reported only in a cervical vertebra attributed to the noasaurid Noasaurus. We also reappraise evidence recently cited against the ceratosaurian interpretation of a recently described astragalocalcaneum from the upper Barremian-lower Aptian San Remo Member of the upper Strzelecki Group in Victoria. Inclusion of the Lightning Ridge cervical vertebra and Victorian astragalocalcaneum into a revised phylogenetic analysis focused on elucidating ceratosaurian affinities reveals support for placement of both specimens within Noasauridae, which among other characters is diagnosed by the presence of a medial eminence on the ascending process of the astragalus. The Lightning Ridge and Victorian specimens simultaneously represent the first noasaurids reported from Australia and the astragalocalcaneum is considered the earliest known example of a noasaurid in the world to date. The recognition of Australian noasaurids further indicates a more widespread Gondwanan distribution of the clade outside of South America, Madagascar and India consistent with the timing of the fragmentation of the supercontinent.
- Published
- 2020
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32. New theropod remains and implications for megaraptorid diversity in the Winton Formation (lower Upper Cretaceous), Queensland, Australia.
- Author
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White MA, Bell PR, Poropat SF, Pentland AH, Rigby SL, Cook AG, Sloan T, and Elliott DA
- Abstract
The holotype specimen of the megaraptorid Australovenator wintonensis , from the Upper Cretaceous Winton Formation (Rolling Downs Group, Eromanga Basin) of central Queensland, is the most complete non-avian theropod found in Australia to date. In fact, the holotype of A. wintonensis and isolated megaraptorid teeth (possibly referable to Australovenator ) constitute the only theropod body fossils reported from the Winton Formation. Herein, we describe a new fragmentary megaraptorid specimen from the Winton Formation, found near the type locality of A. wintonensis . The new specimen comprises parts of two vertebrae, two metatarsals, a pedal phalanx and multiple unidentifiable bone fragments. Although the new megaraptorid specimen is poorly preserved, it includes the only megaraptorid vertebrae known from Queensland. The presence of pleurocoels and highly pneumatic caudal centra with camerate and camellate internal structures permit the assignment of these remains to Megaraptora gen. et sp. indet. A morphological comparison revealed that the distal end of metatarsal II and the partial pedal phalanx II-1 of the new specimen are morphologically divergent from Australovenator . This might indicate the presence of a second megaraptorid taxon in the Winton Formation, or possibly intraspecific variation., Competing Interests: We declare we have no competing interests., (© 2020 The Authors.)
- Published
- 2020
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33. High-latitude neonate and perinate ornithopods from the mid-Cretaceous of southeastern Australia.
- Author
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Kitchener JL, Campione NE, Smith ET, and Bell PR
- Subjects
- Animals, Climate, Geography, New South Wales, Phylogeny, Dinosaurs anatomy & histology, Femur, Fossils
- Abstract
Dinosaurs were remarkably climate-tolerant, thriving from equatorial to polar latitudes. High-paleolatitude eggshells and hatchling material from the Northern Hemisphere confirms that hadrosaurid ornithopods reproduced in polar regions. Similar examples are lacking from Gondwanan landmasses. Here we describe two non-iguanodontian ornithopod femora from the Griman Creek Formation (Cenomanian) in New South Wales, Australia. These incomplete proximal femora represent the first perinatal ornithopods described from Australia, supplementing neonatal and slightly older 'yearling' specimens from the Aptian-Albian Eumeralla and Wonthaggi formations in Victoria. While pseudomorphic preservation obviates histological examination, anatomical and size comparisons with Victorian specimens, which underwent previous histological work, support perinatal interpretations for the Griman Creek Formation femora. Estimated femoral lengths (37 mm and 45 mm) and body masses (113-191 g and 140-236 g), together with the limited development of features in the smallest femur, suggest a possible embryonic state. Low body masses (<1 kg for 'yearlings' and ~20 kg at maturity) would have precluded small ornithopods from long-distance migration, even as adults, in the Griman Creek, Eumeralla, and Wonthaggi formations. Consequently, these specimens support high-latitudinal breeding in a non-iguanodontian ornithopod in eastern Gondwana during the early Late Cretaceous.
- Published
- 2019
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34. Integumentary structure and composition in an exceptionally well-preserved hadrosaur (Dinosauria: Ornithischia).
- Author
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Barbi M, Bell PR, Fanti F, Dynes JJ, Kolaceke A, Buttigieg J, Coulson IM, and Currie PJ
- Abstract
Preserved labile tissues (e.g., skin, muscle) in the fossil record of terrestrial vertebrates are increasingly becoming recognized as an important source of biological and taphonomic information. Here, we combine a variety of synchrotron radiation techniques with scanning electron and optical microscopy to elucidate the structure of 72 million-year-old squamous (scaly) skin from a hadrosaurid dinosaur from the Late Cretaceous of Alberta, Canada. Scanning electron and optical microscopy independently reveal that the three-dimensionally preserved scales are associated with a band of carbon-rich layers up to a total thickness of ∼75 microns, which is topographically and morphologically congruent with the stratum corneum in modern reptiles. Compositionally, this band deviates from that of the surrounding sedimentary matrix; Fourier-transform infrared spectroscopy and soft X-ray spectromicroscopy analyses indicate that carbon appears predominantly as carbonyl in the skin. The regions corresponding to the integumentary layers are distinctively enriched in iron compared to the sedimentary matrix and appear with kaolinite-rich laminae. These hosting carbonyl-rich layers are apparently composed of subcircular bodies resembling preserved cell structures. Each of these structures is encapsulated by calcite/vaterite, with iron predominantly concentrated at its center. The presence of iron, calcite/vaterite and kaolinite may, independently or collectively, have played important roles in the preservation of the layered structures., Competing Interests: James J. Dynes is employed by Canadian Light Source Inc., (©2019 Barbi et al.)
- Published
- 2019
- Full Text
- View/download PDF
35. Isisfordia molnari sp. nov . , a new basal eusuchian from the mid-Cretaceous of Lightning Ridge, Australia.
- Author
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Hart LJ, Bell PR, Smith ET, and Salisbury SW
- Abstract
The Australian Mesozoic crocodyliform record is sparse in comparison to other Gondwanan localities. A single formally-named taxon is known from this interval; Isisfordia duncani (Winton Formation, Albian-Turonian, Queensland). We present a previously undescribed crocodyliform braincase from the Griman Creek Formation (Cenomanian), New South Wales, which we assign to Isisfordia molnari sp. nov. Assignment to the genus is based on the possession of a newly-defined autapomorphy of Isisfordia : a broadly exposed prootic within the supratemporal foramen. A second autapomorphy of I. duncani (maximum diameter of the caudal aperture of the cranioquadrate siphonium approximately one-third the mediolateral width of the foramen magnum, with the lateral wall of the caudal aperture formed exclusively by the quadrate) may also be present in I. molnari ; however, definitive recognition of this feature is marred by incomplete preservation. The new taxon is differentiated from I. duncani based on the absence of a median ridge on the parietal, and the lack of characteristic ridges on the parietal that form the medial margin of the supratemporal foramina. Reanalysis of a second specimen (the former holotype of the nomen dubium, 'Crocodylus (Bottosaurus) selaslophensis' ) allows for its referral to the genus Isisfordia . Crucial to this reappraisal is the reinterpretation of the specimen as a partial maxilla, not the dentary as previously thought. This maxillary fragment possesses specific characteristics shared only with I. duncani ; namely an alveolar groove. However, several key features differentiate the maxillary fragment from I. duncani , specifically the presence of continuous alveolar septa, the thickening of the medial alveolar rim, and the alveolar and crown base morphology. These findings constitute the first evidence of Isisfordia outside of the type locality and indicate its widespread occurrence on the freshwater floodplains along the eastern margin of the epeiric Eromanga Sea during the Albian-Cenomanian., Competing Interests: The authors declare there are no competing interests. Although the new taxon has been named in honour of one of the reviewers, this change was made after his initial review of the manuscript. We feel this name is appropriate as it reflects the reviewer’s (Ralph Molnar) considerable contribution to palaeontology in Australia, and his prior work on crocodyliform fossils from Lightning Ridge.
- Published
- 2019
- Full Text
- View/download PDF
36. Correction to: 'New theropod (Tetanurae: Avetheropoda) material from the 'mid'-Cretaceous Griman Greek Formation at Lightning Ridge, New South Wales, Australia'.
- Author
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Brougham T, Smith ET, and Bell PR
- Abstract
[This corrects the article DOI: 10.1098/rsos.180826.].
- Published
- 2019
- Full Text
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37. New theropod (Tetanurae: Avetheropoda) material from the 'mid'-Cretaceous Griman Creek Formation at Lightning Ridge, New South Wales, Australia [corrected].
- Author
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Brougham T, Smith ET, and Bell PR
- Abstract
The limited fossil record of Australian Cretaceous theropods is dominated by megaraptorids, reported from associated and isolated material from the Early Cretaceous of Victoria and the 'Mid'-Cretaceous of central-north New South Wales and central Queensland. Here, we report on new postcranial theropod material from the early Late Cretaceous Griman Creek Formation at Lightning Ridge. Among this new material is an associated set consisting of two anterior caudal vertebrae and a pubic peduncle of the ilium, to which a morphologically similar partial vertebral centra from a separate locality is tentatively referred. These elements display a combination of characteristics that are present in megaraptorid and carcharodontosaurid theropods, including camellate internal organization of the vertebral centra, ventrally keeled anterior caudal centra and a pubic peduncle of the ilium with a ventral surface approximately twice as long anteroposteriorly as mediolaterally wide. Unfortunately, a lack of unambiguous synapomorphies precludes accurate taxonomic placement; however, avetheropodan affinities are inferred. This new material represents the second instance of a medium-sized theropod from this interval, and only the third known example of associated preservation in an Australian theropod. Additional isolated theropod material is also described, including an avetheropodan femoral head that shows similarities to Allosaurus and Australovenator , and a mid-caudal vertebral centrum bearing pneumatic foraminae and extensive camellae that is referrable to Megaraptora and represents the first axial skeletal element of a megaraptorid described from Lightning Ridge., Competing Interests: We have no competing interests.
- Published
- 2019
- Full Text
- View/download PDF
38. Ornithopod diversity in the Griman Creek Formation (Cenomanian), New South Wales, Australia.
- Author
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Bell PR, Herne MC, Brougham T, and Smith ET
- Abstract
During the Early Cretaceous, dinosaur communities of the Australian-Antarctic rift system (Eumeralla and Wonthaggi formations) cropping out in Victoria were apparently dominated by a diverse small-bodied 'basal ornithopod' fauna. Further north, in Queensland (Winton and Mackunda formations), poorly-represented small-bodied ornithopods coexisted with large-bodied iguanodontians. Our understanding of the ornithopod diversity from the region between the Australian-Antarctic rift and Queensland, represented by Lightning Ridge in central-northern New South Wales (Griman Creek Formation), has been superficial. Here, we re-investigate the ornithopod diversity at Lightning Ridge based on new craniodental remains. Our findings indicate a diverse ornithopod fauna consisting of two-to-three small-bodied non-iguanodontian ornithopods (including Weewarrasaurus pobeni gen. et sp. nov.), at least one indeterminate iguanodontian, and a possible ankylopollexian. These results support those of previous studies that favour a general abundance of small-bodied basal ornithopods in Early to mid-Cretaceous high-latitude localities of southeastern Australia. Although these localities are not necessarily time-equivalent, increasing evidence indicates that Lightning Ridge formed a 'meeting point' between the basal ornithopod-dominated localities in Victoria and the sauropod-iguanodontian faunas in Queensland to the north., Competing Interests: Elizabeth Smith is an affiliate of the Australian Opal Centre (AOC).
- Published
- 2018
- Full Text
- View/download PDF
39. Tyrannosauroid integument reveals conflicting patterns of gigantism and feather evolution.
- Author
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Bell PR, Campione NE, Persons WS 4th, Currie PJ, Larson PL, Tanke DH, and Bakker RT
- Subjects
- Animals, Biological Evolution, Feathers, Fossils, Integumentary System, Gigantism
- Abstract
Recent evidence for feathers in theropods has led to speculations that the largest tyrannosaurids, including Tyrannosaurus rex , were extensively feathered. We describe fossil integument from Tyrannosaurus and other tyrannosaurids ( Albertosaurus, Daspletosaurus, Gorgosaurus and Tarbosaurus ), confirming that these large-bodied forms possessed scaly, reptilian-like skin. Body size evolution in tyrannosauroids reveals two independent occurrences of gigantism; specifically, the large sizes in Yutyrannus and tyrannosaurids were independently derived. These new findings demonstrate that extensive feather coverings observed in some early tyrannosauroids were lost by the Albian, basal to Tyrannosauridae. This loss is unrelated to palaeoclimate but possibly tied to the evolution of gigantism, although other mechanisms exist., (© 2017 The Author(s).)
- Published
- 2017
- Full Text
- View/download PDF
40. Isolated teeth of Anhangueria (Pterosauria: Pterodactyloidea) from the Lower Cretaceous of Lightning Ridge, New South Wales, Australia.
- Author
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Brougham T, Smith ET, and Bell PR
- Abstract
The fossil record of Australian pterosaurs is sparse, consisting of only a small number of isolated and fragmentary remains from the Cretaceous of Queensland, Western Australia and Victoria. Here, we describe two isolated pterosaur teeth from the Lower Cretaceous (middle Albian) Griman Creek Formation at Lightning Ridge (New South Wales) and identify them as indeterminate members of the pterodactyloid clade Anhangueria. This represents the first formal description of pterosaur material from New South Wales. The presence of one or more anhanguerian pterosaurs at Lightning Ridge correlates with the presence of 'ornithocheirid' and Anhanguera -like pterosaurs from the contemporaneous Toolebuc Formation of central Queensland and the global distribution attained by ornithocheiroids during the Early Cretaceous. The morphology of the teeth and their presence in the estuarine- and lacustrine-influenced Griman Creek Formation is likely indicative of similar life habits of the tooth bearer to other members of Anhangueria., Competing Interests: The authors declare there are no competing interests.
- Published
- 2017
- Full Text
- View/download PDF
41. How Many of You Can Read But Still Not See? A Comment on a Recent Review of Carotid Guidelines.
- Author
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Veith FJ and Bell PR
- Subjects
- Humans, Angioplasty methods, Asymptomatic Diseases, Carotid Stenosis therapy, Endarterectomy, Carotid methods, Ischemic Attack, Transient prevention & control, Practice Guidelines as Topic, Stents, Stroke prevention & control
- Published
- 2016
- Full Text
- View/download PDF
42. Rivaroxaban and retropharyngeal haemorrhage.
- Author
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McCarter JA, Bell PR, McCadden L, and Scally C
- Subjects
- Aged, Atrial Fibrillation, Deglutition Disorders etiology, Dysphonia etiology, Emergency Service, Hospital, Humans, Male, Neck, Pharynx, Factor Xa Inhibitors adverse effects, Hemorrhage etiology, Rivaroxaban adverse effects
- Abstract
Haemorrhage is a well-known and accepted complication of anticoagulation. A retropharyngeal haemorrhage (RH) is a rare condition that without prompt recognition and management may result in fatal complications. We report a case of RH in a 67-year-old man anticoagulated with rivaroxaban for atrial fibrillation. The patient presented to the emergency department, with a two-day history of atraumatic right-sided neck swelling and associated progressive odynophagia, dysphagia and dysphonia. Rivaroxaban is a potent new oral anticoagulant that has been approved for use by National Institute for Health and Care Excellence (NICE) but still has no approved reversal agent. Despite its rarity, an RH is a potentially life threatening complication of anticoagulation that must be carefully considered. This is especially true for a drug that cannot be easily reversed. We present a discussion of this case presentation with possible differential diagnoses and a review of the literature, and recommend the use of Capp's triad as a diagnostic criterion., (2016 BMJ Publishing Group Ltd.)
- Published
- 2016
- Full Text
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43. The dentary of Australovenator wintonensis (Theropoda, Megaraptoridae); implications for megaraptorid dentition.
- Author
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White MA, Bell PR, Cook AG, Poropat SF, and Elliott DA
- Abstract
Megaraptorid theropods were an enigmatic group of medium-sized predatory dinosaurs, infamous for the hypertrophied claw on the first manual digit. Megaraptorid dentition is largely restricted to isolated teeth found in association with skeletal parts; however, the in situ maxillary dentition of Megaraptor was recently described. A newly discovered right dentary pertaining to the Australovenator holotype preserves in situ dentition, permitting unambiguous characterisation of the dentary tooth morphology. The new jaw is virtually complete, with an overall elongate, shallow profile, and fifteen visible in situ teeth at varying stages of eruption. In situ teeth confirm Australovenator exhibited modest pseudoheterodonty, recurved lateral teeth with a serrate distal carina and reduced mesial carina, similar to other megaraptorids. Australovenator also combines of figure-of-eight basal cross-section with a lanceolate shape due to the presence of labial and lingual depressions and the lingual twist of the distal carina. Computed tomography and three-dimensional imagery provided superior characterisation of the dentary morphology and enabled an accurate reconstruction to a pre-fossilised state. The newly established dental morphology also afforded re-evaluation of isolated theropod teeth discovered at the Australovenator holotype locality and from several additional Winton Formation localities. The isolated Winton teeth are qualitatively and quantitatively similar to the in situ dentary teeth of Australovenator, but are also morphometrically similar to Abelisauridae, Allosauridae, Coelophysoidea, Megalosauridae and basal Tyrannosauroidea. Qualitative characters, however, clearly distinguish the teeth of Australovenator and the isolated Winton teeth from all other theropods. Evidence from teeth suggests megaraptorids were the dominant predators in the Winton Formation, which contrasts with other penecontemporaneous Gondwanan ecosystems.
- Published
- 2015
- Full Text
- View/download PDF
44. POST OPERATIVE RECOVERY TIME: AN INTERNATIONAL SURVEY OF ENT SURGEONS ADVICE.
- Author
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Bell PR, Dick D, and Adair R
- Subjects
- Humans, Ireland, Postoperative Period, Surveys and Questionnaires, Time Factors, United Kingdom, Convalescence, Otorhinolaryngologic Surgical Procedures, Patient Education as Topic
- Published
- 2015
45. A review of the management of 84 cases of nasal polyposis in a Tertiary Otorhinolaryngology Centre: Our experience.
- Author
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Wooles NR, Bell PR, and Adair R
- Subjects
- Adult, Aged, Aged, 80 and over, Disease Management, Female, Humans, Male, Middle Aged, Nasal Polyps pathology, Retrospective Studies, Young Adult, Nasal Polyps surgery, Nasal Surgical Procedures standards
- Published
- 2015
- Full Text
- View/download PDF
46. Forearm Range of Motion in Australovenator wintonensis (Theropoda, Megaraptoridae).
- Author
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White MA, Bell PR, Cook AG, Barnes DG, Tischler TR, Bassam BJ, and Elliott DA
- Subjects
- Animals, Dinosaurs anatomy & histology, Humerus anatomy & histology, Dinosaurs physiology, Humerus physiology, Models, Biological, Range of Motion, Articular physiology
- Abstract
The hypertrophied manual claws and modified manus of megaraptoran theropods represent an unusual morphological adaptation among carnivorous dinosaurs. The skeleton of Australovenator wintonensis from the Cenomanian of Australia is among the most complete of any megaraptorid. It presents the opportunity to examine the range of motion of its forearm and the function of its highly modified manus. This provides the basis for behavioural inferences, and comparison with other Gondwanan theropod groups. Digital models created from computed tomography scans of the holotype reveal a humerus range of motion that is much greater than Allosaurus, Acrocanthosaurus, Tyrannosaurus but similar to that of the dromaeosaurid Bambiraptor. During flexion, the radius was forced distally by the radial condyle of the humerus. This movement is here suggested as a mechanism that forced a medial movement of the wrist. The antebrachium possessed a range of motion that was close to dromaeosaurids; however, the unguals were capable of hyper-extension, in particular manual phalanx I-2, which is a primitive range of motion characteristic seen in allosaurids and Dilophosaurus. During flexion, digits I and II slightly converge and diverge when extended which is accentuated by hyperextension of the digits in particular the unguals. We envision that prey was dispatched by its hands and feet with manual phalanx I-2 playing a dominant role. The range of motion analysis neither confirms nor refutes current phylogenetic hypotheses with regards to the placement of Megaraptoridae; however, we note Australovenator possessed, not only a similar forearm range of motion to some maniraptorans and basal coelurosaurs, but also similarities with Tetanurans (Allosauroids and Dilophosaurus).
- Published
- 2015
- Full Text
- View/download PDF
47. TRACHEOSTOMY: WE NEED TO KNOW A HOLE LOT MORE.
- Author
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Purcell B, Bell PR, and Stewart R
- Subjects
- Humans, Northern Ireland, Surveys and Questionnaires, Clinical Competence, Medical Staff, Hospital standards, Self Efficacy, Tracheostomy education
- Published
- 2015
48. Traumatic rupture of sternocleidomastoid muscle following an epileptic seizure.
- Author
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Wooles NR, Bell PR, and Korda M
- Subjects
- Adult, Humans, Male, Neck Injuries diagnostic imaging, Neck Injuries therapy, Neck Muscles diagnostic imaging, Physical Therapy Modalities, Rupture diagnostic imaging, Rupture therapy, Ultrasonography, Epilepsy, Tonic-Clonic complications, Neck Injuries etiology, Neck Muscles injuries, Rupture etiology, Seizures complications
- Abstract
A 29-year-old man, a known epileptic, presented to an accident and emergency department following a tonic-clonic seizure, suffering a second seizure in the department. Subsequently, he reported neck pain, swelling and stiffness. An otorhinolaryngology neck examination revealed a tender left side with two palpable masses and a reduced range of movement. Ultrasound confirmed a ruptured middle third of the left sternocleidomastoid muscle, which was successfully treated non-surgically with analgaesia and intensive physiotherapy. Uncommonly, sternocleidomastoid muscle rupture has been reported following high-velocity trauma, but to the best of our knowledge this is the first case described in the literature following an epileptic seizure., (2014 BMJ Publishing Group Ltd.)
- Published
- 2014
- Full Text
- View/download PDF
49. Breathing life into dinosaurs: tackling challenges of soft-tissue restoration and nasal airflow in extinct species.
- Author
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Bourke JM, Porter WM, Ridgely RC, Lyson TR, Schachner ER, Bell PR, and Witmer LM
- Subjects
- Animals, Dinosaurs physiology, Imaging, Three-Dimensional methods, Tomography, X-Ray Computed methods, Dinosaurs anatomy & histology, Extinction, Biological, Models, Anatomic, Nasal Cavity anatomy & histology, Respiration
- Abstract
The nasal region plays a key role in sensory, thermal, and respiratory physiology, but exploring its evolution is hampered by a lack of preservation of soft-tissue structures in extinct vertebrates. As a test case, we investigated members of the "bony-headed" ornithischian dinosaur clade Pachycephalosauridae (particularly Stegoceras validum) because of their small body size (which mitigated allometric concerns) and their tendency to preserve nasal soft tissues within their hypermineralized skulls. Hypermineralization directly preserved portions of the olfactory turbinates along with an internal nasal ridge that we regard as potentially an osteological correlate for respiratory conchae. Fossil specimens were CT-scanned, and nasal cavities were segmented and restored. Soft-tissue reconstruction of the nasal capsule was functionally tested in a virtual environment using computational fluid dynamics by running air through multiple models differing in nasal soft-tissue conformation: a bony-bounded model (i.e., skull without soft tissue) and then models with soft tissues added, such as a paranasal septum, a scrolled concha, a branched concha, and a model combining the paranasal septum with a concha. Deviations in fluid flow in comparison to a phylogenetically constrained sample of extant diapsids were used as indicators of missing soft tissue. Models that restored aspects of airflow found in extant diapsids, such as appreciable airflow in the olfactory chamber, were judged as more likely. The model with a branched concha produced airflow patterns closest to those of extant diapsids. These results from both paleontological observation and airflow modeling indicate that S. validum and other pachycephalosaurids could have had both olfactory and respiratory conchae. Although respiratory conchae have been linked to endothermy, such conclusions require caution in that our re-evaluation of the reptilian nasal apparatus indicates that respiratory conchae may be more widespread than originally thought, and other functions, such as selective brain temperature regulation, could be important., (© 2014 Wiley Periodicals, Inc.)
- Published
- 2014
- Full Text
- View/download PDF
50. So you want to be an otorhinolaryngologist?
- Author
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Bell PR
- Subjects
- Humans, Job Description, United Kingdom, Career Choice, Otolaryngology education
- Published
- 2014
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