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Journal article
A revision of the ‘coelophysoid-grade’ theropod specimen from the Lower Jurassic of the Isle of Skye (Scotland )
The broadest diversification of early predatory dinosaurs is represented by the ‘coelophysoid-grade’ neotheropods, but their Hettangian–Sinemurian ( 191–201 Ma) record is scarce worldwide. More information is needed to shed light on the evolution of this dinosaur group after the end-Triassic mass extinction ( 201 Ma). Here we revisit the anatomy...Ezcurra, Martín D ; Marke, Daniel ; Walsh, Stig A ; Brusatte, Stephen L
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Journal article
Middle Jurassic fossils document an early stage in salamander evolution
Salamanders are an important group of living amphibians and model organisms for understanding locomotion, development, regeneration, feeding, and toxicity in tetrapods. However, their origin and early radiation remain poorly understood, with early fossil stem-salamanders so far represented by larval or incompletely known taxa. This poor record also limits understanding of...Jones, Marc E H ; Benson, Roger B J ; Skutschas, Pavel ; Hill, Lucy ; Panciroli, Elsa …
AMPHIBIANS , PHYLOGENY , JURASSIC , SALAMANDER, and EVOLUTION
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Journal article
The braincase and inner ear of ‘Metriorhynchus’ cf. ‘M.’ brachyrhynchus–implications for aquatic sensory adaptations in crocodylomorphs
During their long evolutionary history crocodylomorphs achieved a great diversity of body sizes, ecomorphotypes and inferred feeding ecologies. One unique group of crocodylomorphs are the thalattosuchians, which lived during the Jurassic and Cretaceous (ca. 191–125 Ma). They transitioned from shallow marine species, like teleosauroids, into fully pelagic forms with paddle...Schwab, Julia A ; Young, Mark T ; Herrera, Yanina ; Witmer, Lawrence M ; Walsh, Stig A …
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Journal article
Ontogenetic variation in the crocodylian vestibular system
Crocodylians today live in tropical to subtropical environments, occupying mostly shallow waters. Their body size changes drastically during ontogeny, as do their skull dimensions and bite forces, which are associated with changes in prey preferences. Endocranial neurosensory structures have also shown to change ontogenetically, but less is known about the...Schwab, Julia A ; Young, Mark T ; Walsh, Stig A ; Witmer, Lawrence M ; Herrera, Yanina …
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Journal article
Tempo and pattern of avian brain size evolution
Relative brain sizes in birds can rival those of primates, but large-scale patterns and drivers of avian brain evolution remain elusive. Here, we explore the evolution of the fundamental brain-body scaling relationship across the origin and evolution of birds. Using a comprehensive dataset sampling> 2,000 modern birds, fossil birds, and...Ksepka, Daniel T ; Balanoff, Amy M ; Smith, N Adam ; Bever, Gabriel S ; Bhullar, Bhart-Anjan S …
neurobiology, co-variation, encephalization, endocast, allometry, paleontology, and aves
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Journal article
Inner ear sensory system changes as extinct crocodylomorphs transitioned from land to water
Major evolutionary transitions, in which animals develop new body plans and adapt to dramatically new habitats and lifestyles, have punctuated the history of life. The origin of cetaceans from land-living mammals is among the most famous of these events. Much earlier, during the Mesozoic Era, many reptile groups also moved...Schwab, Julia A ; Young, Mark T ; Neenan, James M ; Walsh, Stig A ; Witmer, Lawrence M …
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Journal article
Halcyornis toliapicus (aves: Lower Eocene, England) indicates advanced neuromorphology in Mesozoic Neornithes
Our recent X-ray micro computer-tomographic (μCT) investigations of Prophaethon shrubsolei and Odontopteryx toliapica from the Lower Eocene London Clay Formation of England revealed the avian brain to have been essentially modern in form by 55 Ma, but that an important vision-related synapomorphy of living birds, the eminentia sagittalis of the...Walsh, Stig A ; Milner, Angela C
Eocene, eminentia sagittalis, London clay, Halcyornis toliapicus, endocranial cast, and brain evolution
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Journal article
Virtual brain endocasts shed new light on the early evolution of modern birds (Neornithes)
This article is included in 'Program and Abstracts', 72nd Annual Meeting Society of Vertebrate Paleontology, October 17—20, 2012.Bourdon, Estelle ; Milner, A C ; Walsh, Stig A
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Book chapter
Directions in palaeoneurology
This collection of papers honours Dr Angela C Milner and her contribution to vertebrate palaeontology, with articles authored by many of her colleagues and former students. These articles encompass studies on the earliest four-legged vertebrates, lizards, marine reptiles, turtles, dinosaurs, birds and mammals, ranging in age from just after the...Walsh, Stig A ; Knoll, Monja A
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Journal article
Inner ear anatomy is a proxy for deducing auditory capability and behaviour in reptiles and birds
Inferences of hearing capabilities and audition-related behaviours in extinct reptiles and birds have previously been based on comparing cochlear duct dimensions with those of living species. However, the relationship between inner-ear bony anatomy and hearing ability or vocalization has never been tested rigorously in extant or fossil taxa. Here, micro-computed...Walsh, Stig A ; Barrett, Paul M ; Milner, Angela C ; Manley, Geoffrey ; Witmer, Lawrence M
reptile, bird, hearing, papilla, basilar, duct, vocalization, and cochlear
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Journal article
Sea dragons of Avalon
Tourists driving through the village2 of Street on their way to Glastonbury might well wonder at the representation of a skeleton on the road sign. Could this perhaps be a warning that this stretch of the A39 is a roadkill hotspot? I (Stig Walsh, once a local inhabitant) suspect that...Walsh, Stig A ; Taylor, Michael A
Street, ichthyosaur, plesiosaur, Somerset, Triassic, and Jurassic
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Book chapter
Reptiles
The coastline of Dorset exposes a long squence of Jurassic age sedimentary rocks which, with its wealth of invertebrate, vertebrate and plant fossils. From the pioneering work of early collectors like Mary Anning onwards, the area has been a cradle of palaeontology. The Lower Lias is particularly fossiliferous and this...Walsh, Stig A ; Milner, Angela C
reptile, fossil Jurassic, and Lias
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Journal article
Exceptionally well-preserved early Eocene fossil reveals cranial and vertebral features of a stem group roller (Aves: Coraciiformes)
Three-dimensionally preserved skulls of small Paleogene land birds are very rare. Here, we describe a cranium and associated partial postcranial remains of an early Eocene stem group roller (Aves: Coraciiformes) from the London Clay of the Isle of Sheppey (England). The fossil shows features of the skull and vertebral column...Mayr, Gerald ; Walsh, Stig A
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Book chapter
The evolution of avian intelligence and sensory capabilities: the fossil evidence
Crocodiles and birds are the only living representatives of Archosauria, a once diverse clade of vertebrates that mastered terrestrial, aerial and aquatic environments during the Mesozoic. Because the braincases of archosaurs are largely ossified, the group has particularly benefited from advances in non-destructive visualisation of endocranial structures over the past...Walsh, Stig A ; Knoll, F
Neurosensory evolution, Wulst, Dinosaur, Flocculus, and Bird
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Journal article
Comparative analysis of vestibular ecomorphology in birds
The bony labyrinth of vertebrates houses the semicircular canals. These sense rotational accelerations of the head and play an essential role in gaze stabilisation during locomotion. The sizes and shapes of the semicircular canals have hypothesised relationships to agility and locomotory modes in many groups, including birds, and a burgeoning...Benson, Roger B J ; Starmer-Jones, Ethan ; Close, Roger A ; Walsh, Stig A
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Journal article
A new Mississippian tetrapod from Fife, Scotland, and its environmental context
The Visean stage of the Mississippian was a time of rapid tetrapod diversification which marks the earliest appearance of temnospondyls, microsaurs and the limbless aïstopods. Tetrapod finds from this stage are very rare and only a dozen sites are known worldwide. Here we announce the discovery of a new Visean...Smithson, Timothy R ; Browne, Michael A E ; Davies, Sarah J ; Marshall, John E A ; Millward, David …
Mississippian, tetrapod, Spathi- cephalidae., Visean, and Asbian
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Journal article
A reassessment of the postcanine dentition and systematics of the tritylodontid Stereognathus (Cynodontia, Triltylodontidae, Mammaliamorpha) from the Middle Jurassic of the United Kingdom
Tritylodontidae was a successful advanced cynodont clade with a close relationship to mammals, but falling outside the clade Mammaliaformes. Stereognathus ooliticus was the first tritylodontid to be named and described in 1854, but since then no comprehensive description for this species has been produced. A second species, S. hebridicus, was...Panciroli, Elsa ; Walsh, Stig A ; Fraser, Nicholas C ; Brusatte, Stephen L ; Corfe, Ian
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Journal article
Open data and digital morphology
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... -
Journal article
Floccular fossa size is not a reliable proxy of ecology and behaviour in vertebrates
The cerebellar floccular and parafloccular lobes are housed in fossae of the periotic region of the skull of different vertebrates. Experimental evidence indicates that the lobes integrate visual and vestibular information and control the vestibulo-ocular reflex, vestibulo-collic reflex, smooth pursuit and gaze holding. Multiple paleoneuroanatomy studies have deduced the behaviour...Ferreira-Cardoso, S ; Araújo, R ; Martins, N E ; Martins, G G ; Walsh, Stig A …