DISCUSSION Nps
The claw geometry of mammals and birds both pedal and manual correlates well with arboreal and terrestrial habitats. In a study of over 500 species of birds, Feduccia 1993 demonstrated that modern ground and tree-dwelling birds could be distinguished on the basis of pedal claw curvature. The claw arc measurements for ground birds ranged from 52.2 to 77.6 , those of perching birds from 101.8 to 125.3 , and those of trunk-climbers form 129.5 to 161.6 Feduccia, 1993 . The ungual phalanges on pedal...
Respiration in Varanids
Lung morphology. Varanids and helodermatids are the only lizards that possess multichambered lungs Perry, 1998 . They are generally large and heterogene-ously subdivided into various chambers, with the apical chambers supplied with inspired air through a cartilage-reinforced secondary bronchus Perry, 1998 . The dorso-medial region of the varanid lung is where the majority of gas exchange occurs via dense parenchyma, while the caudal sacculated sections are poorly vascularized, highly compliant...
MATERIALS AND METHODS Osteological Correlates of Known Skin Structures
Because ceratopsid horn cores and bosses are novel structures that have no direct homologs in extant taxa an extant phylogenetic bracket EPB level III inference per Witmer, 1995 , we compared these structures to convergent structures in extant taxa to address structural and functional relationships. A diverse group of extant amniotes comprising 96 specimens from 84 taxa was sampled to test relationships between skin structures and underlying bone morphology Table 1 . Convergent examples of...
ACKNOWLEDGMENTS Fmy
Marina Sereda assisted in all cataloging, photographing, and describing of all theropod teeth. H. David Sheets copied and mailed morphometric software, as well as gave input on software applications. Kathleen M. Scott, George R. McGhee, and Kathryn A. Weiss gave critical comments on this manuscript. Christine L. Chandler provided necessary literature. Helpful advice was given by Peter Dodson, Henry John-Alder, Robert J. Blumenschine, Peter J. Morin, Raymond R. Rogers, Rudyard Sadlier, and...
INTRODUCTION Xgb
The field of population biology was revolutionized in the 1930s and 40s with the application of actuary tables derived from the insurance industry to infer population dynamics the balance between mortality rates and attrition that creates the demography of a population Pearl and Miner, 1935 Deevey, 1947 . Life tables, as they are referred to in ecology, serve as a foundation from which one can study influences on population structure such as predation, accidents, disease, growth rates,...
Hypotheses Tested in This Study
The two most prominent hypotheses of integumentary structures described a flat keratinous pad and a rhinoceros-like horn are supplemented by several other morphological hypotheses in this study Fig. 3 . The additional hypotheses represent combinations of different integumentary tissues. Some of these combinations are represented by structures in extant taxa that have not previously been suggested as analogs for Pachyrhi-nosaurus horns e.g., hornbill casques , whereas other combinations are not...
Dodson
femur can be determined. Contrary to expectation, the authors reject their hypothesis, a result that will disappoint some paleobiologists. Phil Manning is a paleontologist at University of Manchester who uses among other research tools the linear accelerator at Stanford University. Manning et al. 2009 use 3D FEA to compare the functionality of an owl claw to that of Velociraptor. The authors conclude that the recurved claws of Velociraptor were suitable for both climbing and prey capture, but...
Info Hup
UALVP 47273, UALVP 16247, and ROM 788 to the model of UALVP 47273, for the purposes of comparing large and small knob weights. UALVP 47273 was constrained at the cranial face of the cranialmost vertebra, and the force was applied to a single node at a point ventral to the estimated centre of mass of the knob. To investigate the distribution of stress within a single vertebra, this force was also applied to the knob vertebrae model. Analysis 5. Knob osteoderms have regions of high, medium, and...
Orbitotemporal Muscles
M. tensor periorbitae mTP-Level IUI' . M. tensor periorbitae i.e., m. levator bulbi attaches to the rostral edge of the prootic in lepidosaurs and a prominent crest on the lateral surface of the laterosphenoid in croc-odylians and birds Haas, 1973 Elzanowski, 1987 . The muscle then attaches to the rostral portion of the orbital septum in birds and lepidosaurs and to the preotic pillars in crocodylians, forming a sling under the orbital contents in all taxa. All dinosaurs possess the caudal...
Discussion 1
These new data provide the first complete picture of the brain endocast in lambeosaurine hadrosaurids at three different ontogenetic stages Fig. 7 . The overall shape of the endocast in corythosaurian lambeosaurines is somewhat different from the well-described condition in hadrosaurine hadrosaurids such as Gryposaurus and Edmontosaurus Lambe, 1920 Lull and Wright, 1942 Ostrom, 1961 Hopson, 1979 Jerison, 2004 . We confirm that the olfactory tracts that connect the olfactory bulbs to the rest of...
Xii 1
2. Lambeosaurus ROM 758 ROM 758 Fig. 2 is the smallest skull in the sample skull length 372 mm . It was originally designated the holotype of a distinct, small-bodied lambeosaurine species, Tetragonosaurus praeceps Parks, 1931 , but has more recently been interpreted as a juvenile Lambeosaurus by Dodson 1975 and Evans et al. 2005 . This specimen was collected from the Campanian-aged strata of the Dinosaur Park Formation 76.5-74.8 Ma at Dinosaur Provincial Park, Alberta. 3. Corythosaurus ROM...
INTRODUCTION Gia
Ankylosaurs were large, quadrupedal ornithischian dinosaurs with extensive dermal ossifications on the head, body, and tail Vickaryous et al., 2004 . Ankylo-saurids had highly modified distal caudal vertebrae forming a handle that, along with terminal osteoderms the knob , formed a club-like structure Fig. 1 terminology after Coombs, 1995 . Several authors Maleev, 1952, 1954 Coombs, 1971, 1979, 1995 have suggested that the tail was used as a defensive weapon. Tail club impact forces vary...
Inner Ear
Casts of the endosseous labyrinths were digitally extracted from all of the tyrannosaurs in the sample here, as well as numerous outgroups. Complete labyrinths are available for T. rex and Gorgosaurus, and a partial labyrinth for CMNH 7541 Fig. 8 . Brochu 2000, 2003 illustrated some fragments of the labyrinth of FMNH PR2081 we were able to extract the semicircular canals completely Fig. 3 , and they resemble those of the better preserved T. rex specimens. All of the tyranno-saur labyrinths are...
MATERIALS AND METHODS Agp
This study describes the vertebral anatomy of extant birds, crocodilians, and varanids, as well as specimens of nonavian theropods. Complete vertebral series in thero-pod dinosaurs are limited however, there are a few taxa that are either represented by multiple specimens or are complete enough for this study. These taxa include the following Sinraptor dongi IVPP 10600 , Allosaurus fra-gilis UUVP 6000 , Tyrannosaurus rex FMNH PR 2081 , and Deinonychus antirrhopus YPM 5204, YPM 5210 . All of the...
LITERATURE CITED Nfr
Bryant HN, Russell AP. 1992. The role of phylogenetic analysis in the inference of unpreserved attributes of extinct taxa. Phil Trans R Soc Lond 337 405-418. Bryant HN, Seymour KN. 1990. Observations and comments on the reliability of muscle reconstruction in fossil vertebrates. J Mor-phol 206 109-117. Buhler P. 1981. Functional anatomy of the avian jaw apparatus. In King AS, McClelland J, editors. Form and Function in Birds, Volume 2. New York Academic Press. p 439-468. Burnham DA. 2004. New...
Cranial Endocast
As noted above, there are published T. rex endocasts for AMNH FR 5029 Osborn, 1912 Hopson, 1979 and FMNH PR2081 Brochu, 2000, 2003 . We generated new endocasts for both of these to provide an independent assessment, and Brochu's 2000 and Hopson's 1979 identifications are largely in accord with ours. For FMNH PR2081, we used the same data as Brochu see above for caveats regarding Brochu's illustrations . For AMNH FR 5029, however, although Osborn 1912 extracted a physical endocast from one side,...
Headbutting behavior ML with Pagel branch lengths and Calibrated branch lengths
Fig. 14. Ancestral character state reconstructions of horn morphology and headbutting behavior in Bovinae cattle and allies . Nodes show proportional likelihoods for each morphological character state with the published topology and branch lengths of Fernandez and Vrba 2005 . Similarity in transformation sequences among extant analogs and centrosaurines. The transition from straight horn core to robust ventrally curved horn-core and flattened boss in Centrosaurinae Fig. 16 is similar to several...
INTRODUCTION Rwu
New pterosaur discoveries and rigorous phylogenetic assessments are refining our understanding of pterosaur evolutionary history and palaeoecology e.g., Hone and Benton, 2007 Witton and Naish, 2008 . However, many questions still remain regarding various aspects of pterosaur biology. Several aspects of the life history of extinct vertebrates are deducible from an analysis of the microstructure of fossilized bone e.g., Chinsamy-Turan, 2005 . For example, histological studies have provided...
Info Dgq
there were natural gaps between the size clusters. Because none of the taxa is represented by a continuous growth series, growth stages are easier to define using the assumption that different elements of a certain size range all pertain to individuals of the same growth stage. As there are few articulated elements available, same-sized elements are assumed to belong to the same growth stage, but not necessarily the same individual. Each growth stage is composed of individual elements that are...
Overview of Adductor Chamber Soft Tissue Anatomy
In general, jaw muscles are divided into groups based on their topological relationships with the branches of the trigeminal nerve Lakjer, 1926 Holliday and Witmer, 2007 . These muscle groups include m. constrictor inter-nus dorsalis, and mm. adductor mandibulae internus, externus, and posterior, most of which are then further divided into smaller muscle bellies. With a few exceptions, such as extant crocodylians, the muscles maintain the same topological relationship with numerous other soft...
III Oen
Apex of coronoid process Bite point at tooth apex Bite points Effective bite point point B projected onto a line at the level of the tooth bases Center of glenoid Effective fulcrums in the levers PR0G0 and BiR0Gi, respectively Centers of left and right glenoid, respectively Positions where the resultant vectors for left and right mandibular adductor muscles, respectively, intersect the level of the tooth row Original position where the resultant vector for right mandibular adductor muscles...
LITERATURE CITED Niu
Carr T. 2003. New insight into the evolution of tyrannosauroid theropods event-pair cracking'' and the integration of ontogenetic and phylogenetic data in paleontology. J Vert Paleontol 23 Suppl. 3 38. Dobzhansky T. 1950. Heredity, environment, and evolution. Science 111 161-166. Forster CA. 1990. The postcranial skeleton of the ornithopod dinosaur Tenontosaurus tilletti. J Vert Paleontol 10 273-294. Fricke HC, Rogers RR, Backlund R, Dwyer CN, Echt S. 2008. Preservation of primary stable...
Extant Material
A subadult juvenile eagle owl Bubo bubo from the biological sciences collections, University of Manchester, was used in this study. The bird had a frozen weight of 1996 g. Bubo bubo is a member of the family Strigidae, which consists of all the typical owls Penteriani et al., 2002 . A fully-intact terminal ungual phalanx and part of the adjacent phalanx, both from pedal digit III of the right pes, were amputated from the Eagle Owl Fig. 1 . The bones, along with all the associated soft tissue...
Info Aaj
aLongevity estimated from histology. Institutional abbreviations LPM, Liaoning Paleontological Museum, Shenyang Normal University, Shenyang, China D, Dalian Natural History Museum, Dalian, Liaoning Province, China PKUVP, School of Earth and Space Sciences, Peking University, Beijing, China IVPP, Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China JZMP, Jinzhou Museum of Paleontology, Jinzhou City, Liaoning Province, China ZMNH, Zhejiang Museum of Natural History,...
Info Mwx
DW, distal width HMCL, head to medial condyle length MDL, midline length MDW, midshaft width ML, maximum length PW, proximal width TRL, 4th trochanter length TRW, shaft width at distal end of 4th trochanter. DW, distal width HMCL, head to medial condyle length MDL, midline length MDW, midshaft width ML, maximum length PW, proximal width TRL, 4th trochanter length TRW, shaft width at distal end of 4th trochanter. are included in Table 2 for the sake of completeness. Proximal and distal ends were...
Respiration in Crocodilians
Lung morphology. Crocodilians possess the most complex lung of any extant nonavian reptile Fig. 1A they are completely enclosed in a separate pleural cavity and frequently attached to the dorsal parietal pleura Perry, 1988 . The multicameral pattern is comparable to the sacculated multichambered lung of vara-nids however, the crocodilian lung is composed of multiple tubular monopodial branching chambers that are connected by intrapulmonary bronchi and lined with perforated interedicular septa...
Juvenile junglefowl
Fig. 2. Chicken Gallus gallus models, in right lateral view, corresponding to cohorts in Table 1. Not to scale scaled to same total length. Labels as in Fig. 1. The skeletons are shown for reference and were not part of inertial properties calculations the translucent outline represents the ''virtual flesh'' of the models. Fig. 2. Chicken Gallus gallus models, in right lateral view, corresponding to cohorts in Table 1. Not to scale scaled to same total length. Labels as in Fig. 1. The skeletons...
Parasaurolophus Olfaction Hypotheses
Brain and nasal cavity endocasts of four corythosaurian lambeosaur-ines Dinosauria Ornithischia were investigated to test hypotheses of cranial crest function related to sensorineural systems. Endocasts were generated through computed tomography and three-dimensional rendering and visualization software. The sample comprises a range of ontogenetic stages from the taxa Lambeosaurus, Corythosaurus, and Hypacrosaurus. Results show that the morphology of brain endocasts differs little from that of...
Keywords nonavian dinosaurs pathological bone radial fibrolamellar bone
Comparative bone microstructure of modern birds has been well researched Enlow and Brown, 1956 , and in recent years, our knowledge of their bone depositional rates and growth has increased substantially Chinsamy, 1995 Castanet et al., 1996 de Margerie et al., 2002 . Likewise, knowledge of the histology of fossilized bones of nonavian dinosaurs Seitz, 1907 de Ricqles, 1980 Reid, 1983, 1986 Chinsamy-Turan, 2005 and Mesozoic birds Houde, 1987 Chinsamy et al., 1994 Chinsamy and Elzanowski, 2001...
Anatomical Review Of Hadrosaur And
CERATOPSID LOWER JAW The Hadrosaur Mandible Osteology and myology. The hadrosaur predentary is a U-shaped element that formed the broad oral margin associated with the duck-bill morphology in this group. The oral margin becomes increasingly denticulate throughout ontogeny and was covered in life by a ram-photheca Sternberg, 1935 . The predentary loosely encloses the symphysis of the dentary, a connection that was held together by ligaments that rapidly decayed after death. Symphyseal suture...
Info Chl
Factor loadings consist of Pearson's correlation coefficients above and P-values below for both x and y coordinates for all landmarks. troodontid teeth are the most negatively positioned. PC1 may therefore be considered an indirect size component. PC2, representing 28.5 of the variance, primarily depicts an increase in mesial denticulation along the component Fig. 9 . MTD has large coefficients that only correlate with HTD significantly. This component shows that distance between the dead-space...
ACKNOWLEDGMENTS Ktn
The author thanks Peter Dodson, Hermann Pfefferkorn, and Fredrick Scatena University of Pennsylvania for their advice on early versions of this manuscript. He also thanks Carrie Ancell and John Horner Museum of the Rockies , Philip Currie University of Alberta , Margaret Feuerstack and Kieran Shepherd Canadian Museum of Nature , James Gardener Royal Tyrrell Museum of Palaeontology , Jeff Person North Dakota Geological Survey , and Kevin Seymour Royal Ontario Museum for help with and access to...
LITERATURE CITED Exr
Alexander, R. McN. 1981. Factors of safety in the structure of animals. Sci Prog 67 109-130. Alexander RM. 1989. Dynamics of dinosaurs and other extinct giants. New York Columbia University Press. p 167. Babout L, Mummery PM, Marrow TJ, Tzelepi A, Withers PJ. 2005. The effect of thermal oxidation on polycrystalline graphite studied by x-ray tomography. Carbon 43 765-774. Barsbold R. 1974. Duelling dinosaurs. Priroda 2 81-83. in Russian . Beaupre GS, Carter DR. 1992. Finite element analysis in...
LITERATURE CITED Fac
Ali F, Zelenitsky DK, Therrien F, Weishampel DB. 2008. Homology of the ethmoid complex'' of tyrannosaurids and its implications for the reconstruction of the olfactory apparatus of non-avian theropods. J Vert Paleontol 28 123-133. Baird IL. 1970. The anatomy of the reptilian ear. In Gans C, Parsons TS, editors. Biology of the reptilian. Vol. II. New York Academic Press. p 193-275. Bakker RT, Williams M, Currie PJ. 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous...
Witmer And Ridgely
Rogers SW. 1998. Exploring dinosaur neuropaleobiology viewpoint computed tomography scanning and analysis of an Allosaurus fragilis endocast. Neuron 21 673-679. Rogers SW. 1999. Allosaurus, crocodiles, and birds evolutionary clues from spiral computed tomography of an endocast. Anat Rec 257 162-173. Rogers SW. 2005. Reconstructing the behaviors of extinct species an excursion into comparative paleoneurology. Am J Med Gen 134A 349-356. Roth TC, II, Cox JG, Lima SL. 2008. Can foraging birds...
OUVC Fdw
Institutional abbreviations OUVC, Ohio University Vertebrate Collection UAM, University of Alaska Museum of the North. Institutional abbreviations OUVC, Ohio University Vertebrate Collection UAM, University of Alaska Museum of the North. similar adaptive changes Kluge, 2005 thus this final criterion cannot falsify a potential analog, but may instead be used to rank hypotheses by their relative support. This third and final test will hereafter be referred to as the correspondence test of analogy
Pneumatic Sinuses of the Braincase
A complex series of air-filled pneumatic sinuses permeate the braincases of tyrannosaurs Fig. 2 , as has been discussed by Russell 1970 , Bakker et al. 1988 , Molnar 1991 , Brochu 2003 , and Currie 2003b , among others. We will base the discussion here largely on our previous attempts to homologize and codify thero-pod pneumatic sinuses Witmer, 1997 Sampson and Witmer, 2007 Witmer and Ridgely, 2008b, in press Witmer et al., 2008 . Figure 2 presents the basic pattern of sinuses in T. rex based...
Keywords heterochrony Hadrosauridae eventpairing development Iguanodontia
Evolutionary change can be difficult to study in taxa for which only fossils remain. In particular, understanding changes in developmental timing, or heterochrony, as potential mechanisms for evolutionary change Gould, Grant sponsors Delaware Valley Paleontological Society, Paleobiology Summer Stipend of the University of Pennsylvania, Binns-Williams Research Stipend, Department of Earth and Environmental Science of the University of Pennsylvania. Correspondence to Merrilee F. Guenther,...
RESULTS Boc
Lambeosaurus and Corythosaurus. The nasal passages of the smallest skulls, ROM 758 and ROM 759, are virtually identical Figs. 2, 4 . The nasal cavity ascends caudodorsally within the premaxilla from the naris at the rostrum to the region directly rostral to the dorsal process of the maxilla. Here, the nasal cavity turns rostrodorsally and then caudodorsally to form an s-shaped loop within the premaxilla. The nasal passage then divides into the lateral diverticulum and a more medial passage that...
AnalysisSpecific Models Boundary Conditions and Material Properties
We applied material properties, a constraint, and a load to finite element meshes in Strand7, and then analyzed for both stress and strain results using the linear solver. Table 3 lists the material properties used in the different analyses, and Table 4 lists the forces, constraints, and other variables used for each mesh of each analysis. Estimates of tail club strike forces are from Arbour 2008 , and follow a method for estimating tail TABLE 3. Material properties used in analyses ARBOUR AND...
Estimation of Inertial Properties for an Extinct Dinosaur
Finally, we test our revised understanding of factors influencing the accuracy of inertial property estimation by revisiting the estimated mass and COM of an adult Tyrannosaurus rex Dinosauria Theropoda , as in Hutchinson et al. 2007 . We applied the same octagonal hoop-based body shape estimation as in Table 5, including the informed tail shape, and air space geometry also Figs. 1F-H, 4, 6, and 7 . Table 6 shows the results for different models with extreme cranial, caudal, dorsal, Fig. 8....
LITERATURE CITED Ykr
Bell DJ, Campbell JG. 1961. Pathological and biochemical observations on virus-induced Osteopetrosis gallinarum. J Comp Pathol 71 85-93. Bloom MA, Domm LV, Nalbandov AX, Bloom W. 1958. Medullary bone of laying chickens. Am J Anat 102 411-451. Bybee PJ, Lee AH, Lamm E-T. 2006. Sizing the Jurassic theropod dinosaur Allosaurus assessing growth strategy and evolution of ontogenetic scaling of limbs. J Morphol 267 347-359. Campbell JG. 1966. A dinosaur bone lesion resembling avian osteo-petrosis and...
Potential Food for Basal Ceratopsians
Basal ceratopsians date from the Late Jurassic to the end of the Cretaceous. Angiosperms, which have often been regarded as the most nutritious plants, did not constitute a significant part of the Early Cretaceous flora. They were the most taxonomically diverse plants in the Late Cretaceous, but they may not have been abundant even in the Late Cretaceous, with conifers and ferns providing the dominant vegetational cover Wing et al., 1993 Tiffney, 1997 Barrett and Willis, 2001 . Although...
ABSTRACT Kss
Ceratopsian dinosaurs were a dominant group of herbivores in Cretaceous terrestrial ecosystems. We hypothesize that an understanding of the feeding system will provide important insight into the evolutionary success of these animals. The mandibular mechanics of eight genera of basal ceratopsians was examined to understand the variability in shape of the jaws and the early evolution of the masticatory system in Ceratopsia. Data were collected on lever arms, cranial angles and tooth row lengths....
ACKNOWLEDGMENTS Cbw
Canada Diagnostic Centres Calgary are gratefully acknowledged for CT scanning of the specimens. Don Henderson, Francois Therrien, and Brandon Strilisky Royal Tyrrell Museum of Palaeontology provided access to specimens. The authors thank Victoria Arbour and Philip Currie for discussion, and Anne Delvaux, Michael Lawrenchuk, and Jia Li for technical support. This manuscript greatly benefited from insightful reviews by Peter Dodson and two anonymous reviewers. Finally, the authors thank Peter...
PHILLIP L MANNING LEE MARGETTS MARK R JOHNSON PHILIP J WITHERS WILLIAM I
1School of Earth, Atmospheric and Environmental Sciences, and The Manchester Museum, University of Manchester, Manchester, United Kingdom 2Department of Earth and Environmental Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 3School of Computer Science, University of Manchester, Manchester, United Kingdom 4School of Materials, University of Manchester, Manchester, United Kingdom 5Faculty of Life Sciences, The Mill, University of Manchester, Manchester, United Kingdom 6Natural...
LITERATURE CITED Xud
Amprino R. 1947. La structure du tissu osseux envisag e comme expression de differences dans la vitesse de l'accroissement. Arch Biol 58 315-330. Bennett SC. 1993. The ontogeny of Pteranodon and other pterosaurs. Paleobiology 19 92-106. Bennett SC. 1995. A statistical study of Rhamphorhynchus from the Solnhofen Limestone of Germany year classes of a single large species. J Paleontol 69 569-580. Bennett SC. 1996. Year-classes of pterosaurs from the Solnhofen Limestone of Germany taxonomic and...
Acknowledgments 1
The authors have benefited from numerous discussions with many dinosaur workers over the years that have impacted this study, including C. Brochu, T. Carr, P. Currie, J. Farlow, M. Henderson, J. Horner, T. Holtz, J. Hurum, P. Larson, P. Makovicky, R. Molnar, H. Osmolska, S. Sampson, P. Sereno, and T. Tsuihiji, among many others. This research was originally presented at the Burpee Museum symposium on The Origin, System-atics, and Paleobiology of the Tyrannosauridae'' in 2005, and the authors...
Zpal
Institute of Paleobiology of the Polish Academy of Sciences Although a number of specimens were subjected to CT scanning see below , the total sample includes specimens studied more traditionally via observation, and this latter category was critical for establishing basic anatomy and assessing variability. Specification of a museum catalog number throughout this article indicates that the original material was studied, whereas observations from casts or the literature are indicated as such....
Ceratopsids Phytoliths
Hadrosaurid and ceratopsid dentaries display traits that suggest divergent functions toward broadly similar diets of fibrous plants. Computed tomographic scans of dentaries of a lambeosaurine and a centro-saurine Centrosaurus aptertus were used to compare feeding function of these animals using finite element analysis FEA . In the hadrosaur, mediolateral expansion of the dentary and elongation of the coronoid process of the surangular were optimally developed to withstand torsion associated...