安徽省黄山地区恐龙(足迹)脚印化石的初步研究

简要报道了安徽省黄山地区所发现的恐龙足迹化石。从脚印的形态和足迹上看,至少有三种不同的恐龙（蜥脚类、兽脚类、鸟脚类）共同生存过,其中多数恐龙为两足行走性的。记述了两个典型的小型兽脚类和小型鸟脚类恐龙所留下的脚印化石。黄山地区恐龙足迹、骨骼化石及其蛋化石的发现,对于研究晚白垩世恐龙生活习性以及古气候环境均有着一定的意义。     

On a theropod scapula (Upper Cretaceous) from the Marília Formation, Bauru Group, Brazil

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

Vestigial skeletal structures in dinosaurs

The existence of vestigial structures is one of the main lines of evidence for macroevolution. Here I introduce a phylogenetic bracketing approach to the identification of vestigial structures and apply it to Dinosauria. According to this approach, a structure is considered vestigial if, in comparison with its homolog in at least three successive outgroups, it is reduced to one-third or less its size relative to adjacent structures and if at least distally it has lost the specialized morphology present in the three outgroups. This approach identifies fingers IV and V as vestigial in dinosaurs in general, II–V in sauropods, III in Tyrannosauridae and Caudipteryx , II and III in Shuvuuia and I and III in modern birds. The entire forelimb distal to the elbow is vestigial in Abelisauridae. Vestigial parts of the pelvic girdle and hindlimb include the pubic shaft in Iguanodontia and Ceratopsia, the entire pubis in Ankylosauria, the first metatarsal in derived Iguanodontia, the first metatarsal shaft in Theropoda and the fifth toe in dinosaurs in general. Derived Centrosaurinae and some Chasmosaurus exhibit vestigial supraorbital horns. Some centrosaurines have a vestigial nasal horn. The antorbital cavity is vestigial in Thyreophora, Iguanodontia and Ceratopsidae. I recommend that this information be exploited to increase public awareness of the evidence for macroevolution.     

A new North American therizinosaurid and the role of herbivory in ‘predatory’ dinosaur evolution

Historically, ecomorphological inferences regarding theropod (i.e. ‘predatory’) dinosaurs were guided by an assumption that they were singularly hypercarnivorous. A recent plethora of maniraptoran discoveries has produced evidence challenging this notion. Here, we report on a new species of maniraptoran theropod, Nothronychus graffami sp. nov. Relative completeness of this specimen permits a phylogenetic reassessment of Therizinosauria—the theropod clade exhibiting the most substantial anatomical evidence of herbivory. In the most comprehensive phylogenetic study of the clade conducted to date, we recover Therizinosauria as the basalmost maniraptoran lineage. Using concentrated changes tests, we present evidence for correlated character evolution among herbivorous and hypercarnivorous taxa and propose ecomorphological indicators for future interpretations of diet among maniraptoran clades. Maximum parsimony optimizations of character evolution within our study indicate an ancestral origin for dietary plasticity and facultative herbivory (omnivory) within the clade. These findings suggest that hypercarnivory in paravian dinosaurs is a secondarily derived dietary specialization and provide a potential mechanism for the invasion of novel morpho- and ecospace early in coelurosaurian evolution—the loss of obligate carnivory and origin of dietary opportunism.     

Do feathered dinosaurs exist? Testing the hypothesis on neontological and paleontological evidence

The origin of birds and avian flight from within the archosaurian radiation has been among the most contentious issues in paleobiology. Although there is general agreement that birds are related to theropod dinosaurs at some level, debate centers on whether birds are derived directly from highly derived theropods, the current dogma, or from an earlier common ancestor lacking suites of derived anatomical characters. Recent discoveries from the Early Cretaceous of China have highlighted the debate, with claims of the discovery of all stages of feather evolution and ancestral birds (theropod dinosaurs), although the deposits are at least 25 million years younger than those containing the earliest known bird Archaeopteryx. In the first part of the study we examine the fossil evidence relating to alleged feather progenitors, commonly referred to as protofeathers, in these putative ancestors of birds. Our findings show no evidence for the existence of protofeathers and consequently no evidence in support of the follicular theory of the morphogenesis of the feather. Rather, based on histological studies of the integument of modern reptiles, which show complex patterns of the collagen fibers of the dermis, we conclude that "protofeathers" are probably the remains of collagenous fiber "meshworks" that reinforced the dinosaur integument. These "meshworks" of the skin frequently formed aberrant patterns resembling feathers as a consequence of decomposition. Our findings also draw support from new paleontological evidence. We describe integumental structures, very similar to "protofeathers," preserved within the rib area of a Psittacosaurus specimen from Nanjing, China, an ornithopod dinosaur unconnected with the ancestry of birds. These integumental structures show a strong resemblance to the collagenous fiber systems in the dermis of many animals. We also report the presence of scales in the forearm of the theropod ornithomimid (bird mimic) dinosaur, Pelecanimimus, from Spain. In the second part of the study we examine evidence relating to the most critical character thought to link birds to derived theropods, a tridactyl hand composed of digits 1-2-3. We maintain the evidence supports interpretation of bird wing digit identity as 2,3,4, which appears different from that in theropod dinosaurs. The phylogenetic significance of Chinese microraptors is also discussed, with respect to bird origins and flight origins. We suggest that a possible solution to the disparate data is that Aves plus bird-like maniraptoran theropods (e.g., microraptors and others) may be a separate clade, distinctive from the main lineage of Theropoda, a remnant of the early avian radiation, exhibiting all stages of flight and flightlessness.     

Body Size Distribution of the Dinosaurs

The distribution of species body size is critically important for determining resource use within a group or clade. It is widely known that non-avian dinosaurs were the largest creatures to roam the Earth. There is, however, little understanding of how maximum species body size was distributed among the dinosaurs. Do they share a similar distribution to modern day vertebrate groups in spite of their large size, or did they exhibit fundamentally different distributions due to unique evolutionary pressures and adaptations? Here, we address this question by comparing the distribution of maximum species body size for dinosaurs to an extensive set of extant and extinct vertebrate groups. We also examine the body size distribution of dinosaurs by various sub-groups, time periods and formations. We find that dinosaurs exhibit a strong skew towards larger species, in direct contrast to modern day vertebrates. This pattern is not solely an artefact of bias in the fossil record, as demonstrated by contrasting distributions in two major extinct groups and supports the hypothesis that dinosaurs exhibited a fundamentally different life history strategy to other terrestrial vertebrates. A disparity in the size distribution of the herbivorous Ornithischia and Sauropodomorpha and the largely carnivorous Theropoda suggests that this pattern may have been a product of a divergence in evolutionary strategies: herbivorous dinosaurs rapidly evolved large size to escape predation by carnivores and maximise digestive efficiency; carnivores had sufficient resources among juvenile dinosaurs and non-dinosaurian prey to achieve optimal success at smaller body size.     

Two new ornithischian dinosaurs (Hypsilophodontia,Ornithopoda) from the Late Jurassic of Russia

Two new dinosaurs, Kulindapteryx ukureica gen. et sp. nov. (Jeholosauridae) and Daurosaurus olovus gen. et sp. nov. (Hypsilophodontidae) from the Ukureisk Formation (?Tithonian, Upper Jurassic) of the Kulinda locality in Transbaikalia (Russia) are described and assigned to Ornithopoda (Ornithischia). The origin and homology of the so-called obturator process of the ischium of Ornithopoda and Theropoda are discussed. The families Jeholosauridae and Hypsilophodontidae as well as Lesothosauridae are considered to belong to the infraorder Hypsilophodontia (Ornithopoda, Ornithischia). It is shown that hypsilophodontians had skin scales divided into bristles.     

The evolution of dinosaur tooth enamel microstructure

The evolution of tooth enamel microstructure in both extinct and extant mammalian groups has been extensively documented, but is poorly known in reptiles, including dinosaurs. Previous intensive sampling of dinosaur tooth enamel microstructure revealed that: (1) the three‐dimensional arrangement of enamel types and features within a tooth—the schmelzmuster—is most useful in diagnosing dinosaur clades at or around the family level; (2) enamel microstructure complexity is correlated with tooth morphology complexity and not necessarily with phylogenetic position; and (3) there is a large amount of homoplasy within Theropoda but much less within Ornithischia. In this study, the examination of the enamel microstructure of 28 additional dinosaur taxa fills in taxonomic gaps of previous studies and reinforces the aforementioned conclusions. Additionally, these new specimens reveal that within clades such as Sauropodomorpha, Neotheropoda, and Euornithopoda, the more basal taxa have simpler enamel that is a precursor to the more complex enamel of more derived taxa and that schmelzmusters evolve in a stepwise fashion. In the particularly well‐sampled clade of Euornithopoda, correlations between the evolution of dental and enamel characters could be drawn. The ancestral schmelzmuster for Genasauria remains ambiguous due to the dearth of basal ornithischian teeth available for study. These new specimens provide new insights into the evolution of tooth enamel microstructure in dinosaurs, emphasizing the importance of thorough sampling within broadly inclusive clades, especially among their more basal members.     

The first dinosaur remains from the Upper Cretaceous of Hungary (Csehbánya Formation, Bakony Mts)

The first dinosaur remains are described from the Upper Cretaceous (Santonian) Csehbánya Formation, Iharkút, Bakony Mts, Hungary. Eight teeth of herbivorous dinosaurs (Rhabdodontidae indet. Nodosauridae indet.) and four teeth belonging to Theropoda indet. are presented. There are also hundreds of fish, frog, turtle and crocodile bones and teeth embedded in fluvial sand of an alluvial plain. Palaeobiogeographic connections towards Provence, the eastern Alps, and southern Carpathians indicate that the Adriatic microplate bearing the fossiliferous succession was an island temporarily connected to the European continent during Late Cretaceous time.     

A new herrerasaurid (Dinosauria, Saurischia) from the Upper Triassic Ischigualasto Formation of northwestern Argentina

Herrerasauridae comprises a basal clade of dinosaurs best known from the Upper Triassic of Argentina and Brazil, which have yielded remains of Herrerasaurus ischigualastensis and Staurikosaurus pricei, respectively. Systematic opinion regarding the position of Herrerasauridae at the base of Dinosauria has varied. Here we describe a new herrerasaurid, Sanjuansaurus gordilloi gen. n., sp. n., based on a partial skeleton from Carnian-age strata of the the Upper Triassic Ischigualasto Formation of northwestern Argentina. The new taxon is diagnosed by numerous features, including long, band-shaped and posterolaterally oriented transverse process on the posterior cervical vertebrae; neural spines of the sixth to eighth dorsal vertebrae, at least, bearing acute anterior and posterior processes; scapula and coracoid with everted lateral margins of the glenoid; and short pubis (63% of the femoral length). Phylogenetic analysis placed Sanjuansaurus within a monophyletic Herrerasauridae, at the base of Theropoda and including Herrerasaurus and Staurikosaurus. The presence of Sanjuansaurus at the base of the Ischigualasto Formation, along with other dinosaurs such as Herrerasaurus, Eoraptor, Panphagia, and Chromogisaurus suggests that saurischian dinosaurs in southwestern Pangea were already widely diversified by the late Carnian rather than increasing in diversity across the Carnian-Norian boundary.     

Using creation science to demonstrate evolution 2: morphological continuity within Dinosauria

Creationist literature claims that sufficient gaps in morphological continuity exist to classify dinosaurs into several distinct baramins (‘created kinds’). Here, I apply the baraminological method called taxon correlation to test for morphological continuity within and between dinosaurian taxa. The results show enough morphological continuity within Dinosauria to consider most dinosaurs genetically related, even by this creationist standard. A continuous morphological spectrum unites the basal members of Saurischia, Theropoda, Sauropodomorpha, Ornithischia, Thyreophora, Marginocephalia, and Ornithopoda with Nodosauridae and Pachycephalosauria and with the basal ornithodirans Silesaurus and Marasuchus. Morphological gaps in the known fossil record separate only seven groups from the rest of Dinosauria. Those groups are Therizinosauroidea + Oviraptorosauria + Paraves, Tazoudasaurus + Eusauropoda, Ankylosauridae, Stegosauria, Neoceratopsia, basal Hadrosauriformes and Hadrosauridae. Each of these seven groups exhibits within‐group morphological continuity, indicating common descent for all the group’s members, even according to this creationist standard.     

Mechanics of posture and gait of some large dinosaurs

Dimensions of dinosaur bones and of models of dinosaurs have been used as the basis for calculations designed to throw light on the posture and gaits of dinosaurs.
Estimates of the masses of some dinosaurs, obtained from the volumes of models, are compared with previous estimates. The positions of dinosaurs' centres of mass, derived from models, show that some large quadrupedal dinosaurs supported most of their weight on their hind legs and were probably capable of rearing up on their hind legs.
Distributions of bending moments along the backs of large dinosaurs are derived from measurements on models. The tensions required in epaxial muscles to enable Diplodocus to stand are calculated. It is likely that the long neck of this dinosaur was supported by some structure running through the notches in the neural spines of its cervical and dorsal vertebrae. The nature of this hypothetical structure is discussed.
An attempt is made to reconstruct the walking gait of sauropod dinosaurs, from the pattern of footprints in fossil tracks.
The dimensions of dinosaur leg bones are compared to predictions for mammals of equal body mass, obtained by extrapolation of allometric equations. Their dimensions are also used to calculate a quantity which is used as an indicator of strength in bending. Comparisons with values for modern animals lead to speculations about the athletic performance of dinosaurs.
Estimates of pressures exerted on the ground by the feet of dinosaurs are used in a discussion of the ability of dinosaurs to walk over soft ground.     

Increases in sampling support the southern Gondwanan hypothesis for the origin of dinosaurs

Dinosaurs were ubiquitous in terrestrial ecosystems through most of the Mesozoic and are still diversely represented in the modern fauna in the form of birds. Recent efforts to better understand the origins of the group have resulted in the discovery of many new species of early dinosaur and their closest relatives (dinosauromorphs). In addition, recent re‐examinations of early dinosaur phylogeny have highlighted uncertainties regarding the interrelationships of the main dinosaur lineages (Sauropodomorpha, Theropoda and Ornithischia), and questioned the traditional hypothesis that the group originated in South Gondwana and gradually dispersed over Pangaea. Here, we use an historical approach to examine the impact of new fossil discoveries and changing phylogenetic hypotheses on biogeographical scenarios for dinosaur origins over 20 years of research time, and analyse the results in the light of different fossil record sampling regimes. Our results consistently optimize South Gondwana as the ancestral area for Dinosauria, as well as for more inclusive clades including Dinosauromorpha, and show that this hypothesis is robust to increased taxonomic and geographic sampling and divergent phylogenetic results. Our results do not find any support for the recently proposed Laurasian origin of dinosaurs and suggest that a southern Gondwanan origin is by far the most plausible given our current knowledge of the diversity of early dinosaurs and non‐dinosaurian dinosauromorphs.     

Ventilatory mechanics from maniraptoran theropods to extant birds

Shared behavioural, morphological and physiological characteristics are indicative of the evolution of extant birds from nonavian maniraptoran dinosaurs. One such shared character is the presence of uncinate processes and respiratory structures in extant birds. Recent research has suggested a respiratory role for these processes found in oviraptorid and dromaeosaurid dinosaurs. By measuring the geometry of fossil rib cage morphology, we demonstrate that the mechanical advantage, conferred by uncinate processes, for movements of the ribs in the oviraptorid theropod dinosaur, Citipati osmolskae, basal avialan species Zhongjianornis yangi, Confuciusornis sanctus and the more derived ornithurine Yixianornis grabaui, is of the same magnitude as found in extant birds. These skeletal characteristics provide further evidence of a flow-through respiratory system in nonavian theropod dinosaurs and basal avialans, and indicate that uncinate processes are a key adaptation facilitating the ventilation of a lung air sac system that diverged earlier than extant birds.     

Ecology,Systematics and Biogeographical Relationships of Dinosaurs,Including a New Theropod,from the Santana Formation (?Albian,Early Cretaceous) of Brazil

Although rare, dinosaurs are well preserved in calcareous nodules of the Santana Formation (Early Cretaceous, ?Albian) of the Araripe Basin, in northeastern Brazil. So far, including only a spinosauroid and three coelurosaurs, the dinosaur fauna appears depauperate. High theropod diversity in assemblages where other dinosaurs are rare or absent is not unique to the Santana Formation. It is seen also in several other assemblages, including Solnhofen and the Maevarano Formation of Madagascar. We consider several factors, including the occurrence of intraguild predation, the possibility that small theropods could subsist in marginal environments, and reliance on coastal resources, that may have been responsible for this apparent ecological imbalance. A new coelurosaur from the Santana Formation, here formally named Mirischia asymmetrica, is shown to be distinct from Santanaraptor placidus [Kellner, A.W.A. () “Short note on a new dinosaur (Theropoda, Coelurosauria) from the Santana Formation (Romualdo Member, Albian) northeastern Brazil”, Boletim do Museu Nacional, Nova Serie, Rio de Janeiro, Brasil 49, 1–8]. Other theropods from the Santana Formation are briefly reviewed. Mirischia is a compsognathid, more similar to the European Compsognathus than to the Asian Sinosauropteryx.     

Mineral nutrition of carnivorous plants: A review

Plant carnivory is one of many possible adaptation strategies to unfavorable conditions, mostly low nutrient availability in wet, acid soils. The following issues concerning the mineral nutrition of carnivorous plants are reviewed: the relative importance of carnivory and root nutrition for growth; which nutrients (elements) from prey are of principal importance for growth; the relationship between mineral and organic nutrition based on carnivory; the interactions between carnivory and root mineral nutrition; and the importance of carnivory under natural conditions. Special attention is paid to aquatic carnivorous plants. Studies on mineral nutrition carried out in laboratory and/or greenhouse conditions are discussed separately from those carried out in field conditions. The emphasis of this review is on recapitulation of original data and conclusions of results from a variety of studies that approach carnivorous plants from an ecophysiological point of view.     

Evolutionary changes in pubic orientation in dinosaurs are more strongly correlated with the ventilation system than with herbivory

Among dinosaurs, the pubis has convergently retroverted four times in Maniraptora (Theropoda) and once in Ornithischia. Although a clear correlation has not been demonstrated, it has been previously proposed that two traits were related to pubic retroversion: the reduced importance of cuirassal ventilation, and a herbivorous diet. Here, we analyse the possible influence of these traits on pubis orientation. Cuirassal ventilation was plesiomorphically present as an accessory ventilation mechanism in Dinosauria and was powered by the M. ischiotruncus, which was probably connected to a propubic pelvis. Cuirassal ventilation was reduced in both Ornithischia and Maniraptora, some of which also evolved herbivory. According to our results, cuirassal ventilation is more strongly correlated with pubic orientation than herbivory. The retroversion of the pubis during the evolution of birds resulted in major changes in the musculature of the tail. These changes increased the efficiency of the pubocaudalis muscles, which enhanced the birds’ capability for take‐off from the ground. The release of the evolutionary constraint on pubic orientation through changes in the ventilatory system can therefore be considered to be an important step in bird evolution.     

被视为恐龙的鸟

尽管于 2 0世纪 2 0年代在亚洲地表层首次发现长有羽毛的恐龙和著名的“龙骨突位点” ,关于鸟类起源的争论仍没有休止。来自化石的证据表明 ,鸟类在进化分支上应归于兽脚类的特殊分支。本文主要阐明完好无损的化石揭示的鸟和非鸟类恐龙的亲密关系和鸟类羽毛及鸟类出现以前的羽毛的起源证据 ,分析体型缩小对飞行进化的重要意义及从新的角度论述鸟类如何飞上了天     

Olfactory acuity in theropods: palaeobiological and evolutionary implications

This research presents the first quantitative evaluation of the olfactory acuity in extinct theropod dinosaurs. Olfactory ratios (i.e. the ratio of the greatest diameter of the olfactory bulb to the greatest diameter of the cerebral hemisphere) are analysed in order to infer the olfactory acuity and behavioural traits in theropods, as well as to identify phylogenetic trends in olfaction within Theropoda. A phylogenetically corrected regression of olfactory ratio to body mass reveals that, relative to predicted values, the olfactory bulbs of (i) tyrannosaurids and dromaeosaurids are significantly larger, (ii) ornithomimosaurs and oviraptorids are significantly smaller, and (iii) ceratosaurians, allosauroids, basal tyrannosauroids, troodontids and basal birds are within the 95% CI. Relative to other theropods, olfactory acuity was high in tyrannosaurids and dromaeosaurids and therefore olfaction would have played an important role in their ecology, possibly for activities in low-light conditions, locating food, or for navigation within large home ranges. Olfactory acuity was the lowest in ornithomimosaurs and oviraptorids, suggesting a reduced reliance on olfaction and perhaps an omnivorous diet in these theropods. Phylogenetic trends in olfaction among theropods reveal that olfactory acuity did not decrease in the ancestry of birds, as troodontids, dromaeosaurids and primitive birds possessed typical or high olfactory acuity. Thus, the sense of smell must have remained important in primitive birds and its presumed decrease associated with the increased importance of sight did not occur until later among more derived birds.     

Theropod Locomotion

Theropod (carnivorous) dinosaurs spanned a range from chicken-sizedto elephant-sized animals. The primary mode of locomotion inthese dinosaurs was fairly conservative: Theropods were erect,digitigrade, striding bipeds. Even so, during theropod evolutionthere were changes in the hip, tail, and hindlimb that undoubtedlyaffected the way these dinosaurs walked and ran, a trend thatreached its extreme in the evolution of birds. Some derivednon-avian theropods developed hindlimb proportions that suggesta greater degree of cursoriality than in more primitive groups.Despite this, fossilized trackways provide no evidence for changesin stride lengths of early as opposed to later non-avian theropods.However, these dinosaurs did take relatively longer strides—atleast compared with footprint length—than bipedal ornithischiandinosaurs or ground birds. Judging from trackway evidence, non-aviantheropods usually walked, and seldom used faster gaits. Thelargest theropods were probably not as fleet as their smallerrelatives.