Emily J Rayfield

Emily J Rayfield
University of Bristol | UB · School of Earth Sciences

PhD University of Cambridge

About

238
Publications
75,512
Reads
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5,432
Citations
Additional affiliations
October 2005 - August 2015
University of Bristol
Position
  • Reader in Palaeobiology
January 2005 - September 2005
Natural History Museum, London
Position
  • PostDoc Position
October 2002 - September 2005
University of Cambridge
Position
  • Researcher

Publications

Publications (238)
Article
The developmental underpinnings and functional consequences of modifications to the limbs during the origin of the tetrapod body plan are increasingly well characterized, but less is understood about the evolution of the tetrapod skull. Decrease in skull bone number has been hypothesized to promote morphological and functional diversification in ve...
Article
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Finite element analysis (FEA) is a commonly used application in biomechanical studies of both extant and fossil taxa to assess stress and strain in solid structures such as bone. FEA can be performed on 3D structures that are generated using various methods, including computed tomography (CT) scans and surface scans. While previous palaeobiological...
Article
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Launch is the most energetically expensive part of flight and is considered a limiting factor in the size of modern flyers. Pterosaurs reached significantly larger sizes than modern flyers and are proposed to have launched either bipedallly or quadrupedally. We investigated the ability of a medium-sized ornithocheiraean pterosaur to assume the pose...
Article
The Siluro-Devonian adaptive radiation of jawed vertebrates, which underpins almost all living vertebrate biodiversity, is characterized by the evolutionary innovation of the lower jaw. Multiple lines of evidence have suggested that the jaw evolved from a rostral gill arch, but when the jaw took on a feeding function remains unclear. We quantified...
Article
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Previous studies of the morphology of the humerus in kangaroos showed that the shape of the proximal humerus could distinguish between arboreal and terrestrial taxa among living mammals, and that the extinct “giant” kangaroos (members of the extinct subfamily Sthenurinae and the extinct macropodine genus Protemnodon ) had divergent humeral anatomie...
Article
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Mosasauroidea, prominent marine lizards (Squamata, Toxicofera) of the final 30 million years of the Cretaceous, have been extensively studied for their morphology, ecology and systematics in the past two centuries. However, the relative roles of biological and physical processes as drivers of their morphological diversification remain uncertain. He...
Article
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Dinosaur evolution is marked by numerous independent shifts from bipedality to quadrupedality. Sauropodomorpha is one of the lineages that transitioned from small bipedal forms to graviportal quadrupeds, with an array of intermediate postural strategies evolving in non-sauropodan sauropodomorphs. This locomotor shift is reflected by multiple modifi...
Article
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The extinct sthenurine (giant, short-faced) kangaroos have been proposed to have a different type of locomotor behavior to extant (macropodine) kangaroos, based both on physical limitations (the size of many exceeds the proposed limit for hopping) and anatomical features (features of the hind limb anatomy suggestive of weight-bearing on one leg at...
Article
Rhynchocephalians are a group of lizard-like diapsid reptiles that were very diverse during the Mesozoic but are now restricted to a single extant genus in New Zealand. Recent cladistic analyses have revealed two major clades, Eusphenodontia and the more crownward Neosphenodontia, but relationships of individual taxa have remained difficult to dete...
Article
Pseudosuchians, archosaurian reptiles more closely related to crocodylians than to birds, exhibited high morphological diversity during the Triassic with numerous examples of morphological convergence described between Triassic pseudosuchians and post‐Triassic dinosaurs. One example is the shuvosaurid Effigia okeeffeae which exhibits an “ostrich‐li...
Article
The Early Carboniferous stem tetrapod Whatcheeria deltae is among the earliest-branching limbed tetrapods represented by multiple near-complete specimens, making it an important taxon in understanding the vertebrate water-to-land transition. However, all preserved skulls of Whatcheeria suffer from post-mortem crushing and lateral compression, which...
Article
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The Triassic (252–201 Ma) marks a major punctuation in Earth history, when ecosystems rebuilt themselves following the devastating Permian-Triassic mass extinction. Herbivory evolved independently several times as ecosystems comprising diverse assemblages of therapsids, parareptiles and archosauromorphs rose and fell, leading to a world dominated b...
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Evolutionary variation in ontogeny played a central role in the origin of the avian skull. However, its influence in subsequent bird evolution is largely unexplored. We assess the links between ontogenetic and evolutionary variation of skull morphology in Strisores (nightbirds). Nightbirds span an exceptional range of ecologies, sizes, life-history...
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Understanding the origin, expansion and loss of biodiversity is fundamental to evolutionary biology. The approximately 26 living species of crocodylomorphs (crocodiles, caimans, alligators and gharials) represent just a snapshot of the group's rich 230-million-year history, whereas the fossil record reveals a hidden past of great diversity and inno...
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Many dinosaurs may have shown ecological differentiation between hatchlings and adults, possibly because of the great size differential. The basal ceratopsian Psitta-cosaurus lujiatunensis is known from thousands of specimens from the Lower Cretaceous of China and these include many so-called 'juvenile clusters.' During the early stages of ontogeny...
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Jaw morphology is closely linked to both diet and biomechanical performance, and jaws are one of the most common Mesozoic mammal fossil elements. Knowledge of the dietary and functional diversity of early mammals informs on the ecological structure of palaeocommunities throughout the longest era of mammalian evolution: the Mesozoic. Here, we analys...
Article
Extreme phenotypic polymorphism is an oft-cited example of evolutionary theory in practise. Although these morphological variations are assumed to be adaptive, few studies have biomechanically tested such hypotheses. Pyrenestes ostrinus (the African seedcracker finch) shows an intraspecific polymorphism in beak size and shape that is entirely diet...
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Birds and crocodiles show radically different patterns of brain development, and it is of interest to compare these to determine the pattern of brain growth expected in dinosaurs. Here we provide atlases of 3D brain (endocast) reconstructions for Alligator mississippiensis (alligator) and Struthio camelus (ostrich) through ontogeny, prepared as dig...
Article
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Sauropodomorph dinosaurs underwent drastic changes in their anatomy and ecology throughout their evolution. The Late Triassic Thecodontosaurus antiquus occupies a basal position within Sauropodomorpha, being a key taxon for documenting how those morphofunctional transitions occurred. Here, we redescribe the braincase osteology and reconstruct the n...
Article
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Triassic archosaurs and stem-archosaurs show a remarkable disparity in their ankle and pelvis morphologies. However, the implications of these different morphologies for specific functions are still poorly understood. Here, we present the first quantitative analysis into the locomotor abilities of a stem-archosaur applying 3D modelling techniques....
Article
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Thecodontosaurus antiquus is a basal sauropodomorph from the Rhaetian locality of Durdham Down in Bristol, U.K. Sauropodomorph material putatively assigned to this species was found at the nearby site of Tytherington. Here, we describe the Tytherington specimens and compare them with T. antiquus and other Late Triassic sauropodomorphs from Britain....
Article
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Analyses of morphological disparity have been used to characterize and investigate the evolution of variation in the anatomy, function and ecology of organisms since the 1980s. While a diversity of methods have been employed, it is unclear whether they provide equivalent insights. Here, we review the most commonly used approaches for characterizing...
Article
Rhynchocephalians were a successful, globally distributed group of diapsid reptiles that thrived in the Mesozoic. Multiple species of Clevosaurus existed worldwide in the Late Triassic and Early Jurassic, characterized by shearing bladelike teeth perhaps functionally analogous to the carnassial teeth of mammals. Morphometric analysis shows that the...
Article
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Large nektonic suspension feeders have evolved multiple times. The apparent trend among apex predators for some evolving into feeding on small zooplankton is of interest for understanding the associated shifts in anatomy and behaviour, while the spatial and temporal distribution gives clues to an inherent relationship with ocean primary productivit...
Article
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The diversifications of Darwin’s finches and Hawaiian honeycreepers are two text-book examples of adaptive radiation in birds. Why these two bird groups radiated while the remaining endemic birds in these two archipelagos exhibit relatively low diversity and disparity remains unexplained. Ecological factors have failed to provide a convincing answe...
Article
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Background The Psittaciformes (parrots and cockatoos) are characterised by their large beaks, and are renowned for their ability to produce high bite forces. These birds also possess a suite of modifications to their cranial architecture interpreted to be adaptations for feeding on mechanically resistant foods, yet the relationship between cranial...
Article
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Finite-element (FE) analysis has been used in palaeobiology to assess the mechanical performance of the jaw. It uses two types of models: tomography-based three-dimensional (3D) models (very accurate, not always accessible) and two-dimensional (2D) models (quick and easy to build, good for broad-scale studies, cannot obtain absolute stress and stra...
Article
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Disparity, the diversity of form and function of organisms, can be assessed from cladistic or phenetic characters , and from discrete characters or continuous characters such as landmarks, outlines, or ratios. But do these different methods of assessing disparity provide comparable results? Here we provide evidence that all metrics correlate signif...
Article
Advances in X‐ray computed tomography (CT) have led to a rise in the use of non‐destructive imaging methods in comparative anatomy. Among these is contrast‐enhanced CT scanning, which employs chemical stains to visualize soft tissues. Specimens may then be ‘digitally dissected’, producing detailed, three‐dimensional digital reconstructions of the s...
Chapter
Functional loading generates stress and strain within the skeleton. Deducing how the skull stresses and strains has the potential to inform on what feeding and other behavioural loads the skeleton can withstand and the functional consequences of changes to shape. When applied in deep time, mechanical analysis of the skeleton may be used to determin...
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Multituberculate mammals thrived during the Mesozoic, but their diversity declined from the mid-late Paleocene onwards, becoming extinct in the late Eocene. The radiation of superficially similar, eutherian rodents has been linked to multituberculate extinction through competitive exclusion. However, characteristics providing rodents with a suppose...
Article
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During the Mesozoic, Crocodylomorpha had a much higher taxonomic and morphological diversity than today. Members of one particularly successful clade, Thalattosuchia, are well‐known for being longirostrine: having long, slender snouts. It has generally been assumed that Thalattosuchia owed their success in part to the evolution of longirostry, lead...
Preprint
Morphological similarities between the extinct Triassic archosauriform clade Phytosauria and extant crocodilians have formed the basis of long-proposed hypotheses of evolutionary convergence. These hypotheses have informed the reconstructions of phytosaur ecology and biology, including feeding preferences, body mass, soft tissue systems, mating beh...
Preprint
Full-text available
Morphological similarities between the extinct Triassic archosauriform clade Phytosauria and extant crocodilians have formed the basis of long-proposed hypotheses of evolutionary convergence. These hypotheses have informed the reconstructions of phytosaur ecology and biology, including feeding preferences, body mass, soft tissue systems, mating beh...
Poster
With the aid of modern technologies such as μCT scanning and 3D model reconstruction, the internal anatomy of fossilized remains can be easily and non-invasively studied. Here we describe the internal anatomical structures and associated bones of the nasal cavity of Riograndia guaibensis, a non-mammaliaform cynodont for the Late Triassic of Brazil....
Article
Extensive research on avian adaptive radiations has led to a presumption that beak morphology predicts feeding ecology in birds. However, this ecomorphological relationship has only been quantified in a handful of avian lineages, where associations are of variable strength, and never at a broad macroevolutionary scale. Here, we used shape analysis...
Poster
Full-text available
This poster is an update on the results of the project since June 2018, and was presented at Society of Vertebrate Paleontology Annual Meeting 2018 for the Edwin H. and Margaret M. Colbert Student Poster Prize session. The following is the abstract that was included in the Society of Vertebrate Paleontology Annual Meeting 2018 (note: the poster inc...
Article
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The evolution of the mammalian jaw is one of the most important innovations in vertebrate history, and underpins the exceptional radiation and diversification of mammals over the last 220 million years1,2. In particular, the transformation of the mandible into a single tooth-bearing bone and the emergence of a novel jaw joint-while incorporating so...
Poster
Full-text available
Skull Mechanics and Functional Morphology of Brasilodontidae, the Sister Clade to Mammals • Only recently have there been qualitative and functional analyses of the cynodont-mammal transition in the skull (1,2). • Brasilodontids are insectivorous nonmammalian cynodonts that share distinct characteristics with Mammaliaformes which have placed them a...
Article
The structure (both gross morphology and internal cellular) of rhodoliths (free-living forms of coralline algae) are important factors in the ability of rhodoliths to create complex habitats. Using Finite Element Analysis, models of the internal structure of rhodoliths have been interrogated to assess how changes to the cellular structure affect st...
Article
A digital cranial endocast of the specimen UFRGS-PV-596-T of Riograndia guaibensis was obtained from μCT scan images. This is a small cynodont, closely related to mammaliaforms, from the Late Triassic of Brazil. Riograndia has large olfactory bulb casts and the cerebral hemispheres region is relatively wider than in other non-mammaliaform cynodonts...
Article
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The morphology of the vertebrate lower jaw has been used to infer feeding ecology, with transformations in mandibular shape and structure likely to have facilitated the emergence of different feeding behaviours in vertebrate evolution. Here we present elliptical Fourier shape and principal component analyses, characterizing and comparing the dispar...
Preprint
Full-text available
Developmental dysplasia of the hip (DDH), a malformation of the acetabulum, is a frequent cause of early onset osteoarthritis. The disease encompasses a spectrum of severities, some of which are more amenable to treatment. Embryonic immobilisation significantly impairs the development of joint shape however the impact of this malformation to the fu...
Conference Paper
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Multituberculates were one of the most successful mammalian orders to have ever lived, persisting for at least 125 million years from the Middle Jurassic through the K-Pg mass extinction to the late Eocene. The cause of multituberculate extinction remains unresolved and has received minimal research attention for several decades. One widely accepte...
Article
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Sauropodomorpha included the largest known terrestrial vertebrates and was the first dinosaur clade to achieve a global distribution. This success is associated with their early adoption of herbivory, and sauropod gigantism has been hypothesized to be a specialization for bulk feeding and obligate high-fiber herbivory. Here, we apply a combination...
Article
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Over the past two decades, the development of methods for visualizing and analysing specimens digitally, in three and even four dimensions, has transformed the study of living and fossil organisms. However, the initial promise that the widespread application of such methods would facilitate access to the underlying digital data has not been fully a...
Article
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Strigiformes are an order of raptorial birds consisting exclusively of owls: the Tytonidae (barn owls) and the Strigidae (true owls), united by a suite of adaptations aiding a keen predatory lifestyle, including robust hind limb elements modified for grip strength. To assess variation in hind limb morphology, we analysed how the dimensions of the m...
Article
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Morphological responses of nonmammalian herbivores to external ecological drivers have not been quantified over extended timescales. Herbivorous nonavian dinosaurs are an ideal group to test for such responses, because they dominated terrestrial ecosystems for more than 155 Myr and included the largest herbivores that ever existed. The radiation of...