Microvertebrates are common in the basal bone bed of the Westbury Formation of England, documenti... more Microvertebrates are common in the basal bone bed of the Westbury Formation of England, documenting a fauna dominated by fishes that existed at the time of the Rhaetian Transgression, some 206 Myr ago. Two sites near Chipping Sodbury, south Gloucestershire, Barnhill Quarry and Chipping Sodbury railway cutting, show differing faunas. Top predators are the large bony fish Severnichthys and the shark Hybodus cloacinus, which preyed on smaller sharks such as Lissodus and Rhomphaiodon. These fishes in turn may have fed on a mixed diet of other fishes and invertebrates, and Lissodus was a shell crusher. Comparisons of these faunas with others described recently from the Bristol region, and from Devon, indicate remarkable faunal similarities in the Rhaetian basal Westbury Formation bone bed over a wide area, based on a variety of ecological statistics that document species diversities and relative abundances. Only the fauna from the Chipping Sodbury railway cutting differs significantly.
Microvertebrates are common in the basal bone bed of the Westbury Formation of England, documenti... more Microvertebrates are common in the basal bone bed of the Westbury Formation of England, documenting a fauna dominated by fishes that existed at the time of the Rhaetian Transgression, some 206 Myr ago. Two sites near Chipping Sodbury, south Gloucestershire, Barnhill Quarry and Chipping Sodbury railway cutting, show differing faunas. Top predators are the large bony fish Severnichthys and the shark Hybodus cloacinus, which preyed on smaller sharks such as Lissodus and Rhomphaiodon. These fishes in turn may have fed on a mixed diet of other fishes and invertebrates, and Lissodus was a shell crusher. Comparisons of these faunas with others described recently from the Bristol region, and from Devon, indicate remarkable faunal similarities in the Rhaetian basal Westbury Formation bone bed over a wide area, based on a variety of ecological statistics that document species diversities and relative abundances. Only the fauna from the Chipping Sodbury railway cutting differs significantly.
Pliosaurs were among the largest predators in Mesozoic seas, and yet their functional anatomy and... more Pliosaurs were among the largest predators in Mesozoic seas, and yet their functional anatomy and feeding biomechanics are poorly understood. A new, well-preserved pliosaur from the Kimmeridgian of Weymouth Bay (UK) revealed cranial adaptations related to feeding. Digital modelling of computed tomography scans allowed reconstruction of missing, distorted regions of the skull and of the adductor musculature, which indicated high bite forces. Size-corrected beam theory modelling showed that the snout was poorly optimised against bending and torsional stresses compared with other aquatic and terrestrial predators, suggesting that pliosaurs did not twist or shake their prey during feeding and that seizing was better performed with post-symphyseal bites. Finite element analysis identified biting-induced stress patterns in both the rostrum and lower jaws, highlighting weak areas in the rostral maxillary-premaxillary contact and the caudal mandibular symphysis. A comparatively weak skull coupled with musculature that was able to produce high forces, is explained as a trade-off between agility, hydrodynamics and strength. In the Kimmeridgian ecosystem, we conclude that Late Jurassic pliosaurs were generalist predators at the top of the food chain, able to prey on reptiles and fishes up to half their own length.
... The teeth of sharks in particular are identifiable to genus and species in many cases (Cuny e... more ... The teeth of sharks in particular are identifiable to genus and species in many cases (Cuny et al., 2004), while teeth of certain ... to survival of bone are carbonate, organic (humate and fluvate) and phosphate species (eg [Johannesson et al., 1996] and [Tang and Johannesson ...
The mass extinction at the Permian-Triassic Boundary (PTB) is said to have been abrupt and probab... more The mass extinction at the Permian-Triassic Boundary (PTB) is said to have been abrupt and probably caused by an extraterrestrial impact. However, evidence from the Global Stratotype Section and Point (GSSP) of the base of the Induan at Meishan, China, shows that the biotic crisis began prior to the level, in beds 25 and 26 at which the postulated impact event occurred. Evidence of such an earlier biotic crisis occurs in other sections in South China, and in central and western Tethyan regions. This event is characterized by the extinction of a range of faunas, including corals, deep-water radiolarians, most fusulinids and pseudotir-olitid ammonoids, and many Permian brachiopods. In all sections, this extinction level is usually a few decimeters to meters below that of the main mass extinction in the event beds (25 and 26) at Meishan, and their correlatives elsewhere. This earlier extinction event happened before the postulated bolide impact at the level of beds 25 and 26, and constrains interpretation of the mechanisms that brought about this greatest mass extinction.
Pliosaurs were a long-lived, ubiquitous group of Mesozoic marine predators attaining large body s... more Pliosaurs were a long-lived, ubiquitous group of Mesozoic marine predators attaining large body sizes (up to 12 m). Despite much being known about their ecology and behaviour, the mechanisms they adopted for prey detection have been poorly investigated and represent a mystery to date. Complex neurovascular systems in many vertebrate rostra have evolved for prey detection. However, information on the occurrence of such systems in fossil taxa is extremely limited because of poor preservation potential. The neurovascular complex from the snout of an exceptionally well-preserved pliosaur from the Kimmeridgian (Late Jurassic, c. 170 Myr ago) of Weymouth Bay (Dorset, UK) is described here for the first time. Using computed tomography (CT) scans, the extensive bifurcating neurovascular channels could be traced through the rostrum to both the teeth and the foramina on the dorsal and lateral surface of the snout. The structures on the surface of the skull and the high concentrations of peripheral rami suggest that this could be a sensory system, perhaps similar to crocodile pressure receptors or shark electroreceptors.
The mass extinction at the Permian-Triassic boundary, 251 million years (Myr) ago, is accepted as... more The mass extinction at the Permian-Triassic boundary, 251 million years (Myr) ago, is accepted as the most profound loss of life on record. Global data compilations indicate a loss of 50% of families or more, both in the sea and on land, and these figures scale to a loss of 80-96% of species, based on rarefaction analyses. This level of loss is confirmed by local and regional-scale studies of marine sections, but the terrestrial record has been harder to analyse in such close detail. Here we document the nature of the event in Russia in a comprehensive survey of 675 specimens of amphibians and reptiles from 289 localities spanning 13 successive geological time zones in the South Urals basin. These changes in diversity and turnover cannot be explained simply by sampling effects. There was a profound loss of genera and families, and simplification of ecosystems, with the loss of small fish-eaters and insect-eaters, medium and large herbivores and large carnivores. Faunal dynamics also changed, from high rates of turnover through the Late Permian period to greater stability at low diversity through the Early Triassic period. Even after 15Myr of ecosystem rebuilding, some guilds were apparently still absent-small fish-eaters, small insect-eaters, large herbivores and top carnivores.
The mass extinction at the Permian-Triassic Boundary (PTB) is said to have been abrupt and probab... more The mass extinction at the Permian-Triassic Boundary (PTB) is said to have been abrupt and probably caused by an extraterrestrial impact. However, evidence from the Global Stratotype Section and Point (GSSP) of the base of the Induan at Meishan, China, shows that the biotic crisis began prior to the level, in beds 25 and 26 at which the postulated impact event occurred. Evidence of such an earlier biotic crisis occurs in other sections in South China, and in central and western Tethyan regions. This event is characterized by the extinction of a range of faunas, including corals, deep-water radiolarians, most fusulinids and pseudotir-olitid ammonoids, and many Permian brachiopods. In all sections, this extinction level is usually a few decimeters to meters below that of the main mass extinction in the event beds (25 and 26) at Meishan, and their correlatives elsewhere. This earlier extinction event happened before the postulated bolide impact at the level of beds 25 and 26, and constrains interpretation of the mechanisms that brought about this greatest mass extinction.
Proceedings of the Geologists' Association, Feb 10, 2015
The Rhaetic Transgression, 210 Myr ago, which marked the end of continental conditions in the
Eu... more The Rhaetic Transgression, 210 Myr ago, which marked the end of continental conditions in the
European Triassic, and the arrival of marine deposition, may have been heralded by the arrival of
burrowing shrimps. Here we document an unusual taphonomic situation, in which classic basal Rhaetic
bone bed is preserved inside a Thalassinoides burrow system at the base of the Westbury Mudstone
Formation, in the highest part of the Blue Anchor Formation, at Charton Bay, Devon, UK. The fauna
comprises four species of sharks and five species of bony fishes. The sharks, Rhomphaiodon (‘Hybodus’),
Duffinselache, Lissodus, and Pseudocetorhinus are small, and include predatory and crushing/
opportunistic feeders. The top predator was the large Severnichthys, typical of Rhaetian ichthyofaunas,
and Gyrolepis was a smaller predator. Late Triassic bony fishes generally included many shell-crushers,
and the Charton Bay assemblage is no exception, with teeth of Sargodon, ‘Lepidotes’, and Dapedium, the
last being a rare record for the British Rhaetic. This kind of burrowed and filled contact occurs elsewhere
at the base of the Westbury Mudstone Formation, and so may be a typical marker of the early phases of
the Rhaetic Transgression.
Microvertebrates are common in the basal bone bed of the Westbury Formation of England, documenti... more Microvertebrates are common in the basal bone bed of the Westbury Formation of England, documenting a fauna dominated by fishes that existed at the time of the Rhaetian Transgression, some 206 Myr ago. Two sites near Chipping Sodbury, south Gloucestershire, Barnhill Quarry and Chipping Sodbury railway cutting, show differing faunas. Top predators are the large bony fish Severnichthys and the shark Hybodus cloacinus, which preyed on smaller sharks such as Lissodus and Rhomphaiodon. These fishes in turn may have fed on a mixed diet of other fishes and invertebrates, and Lissodus was a shell crusher. Comparisons of these faunas with others described recently from the Bristol region, and from Devon, indicate remarkable faunal similarities in the Rhaetian basal Westbury Formation bone bed over a wide area, based on a variety of ecological statistics that document species diversities and relative abundances. Only the fauna from the Chipping Sodbury railway cutting differs significantly.
Microvertebrates are common in the basal bone bed of the Westbury Formation of England, documenti... more Microvertebrates are common in the basal bone bed of the Westbury Formation of England, documenting a fauna dominated by fishes that existed at the time of the Rhaetian Transgression, some 206 Myr ago. Two sites near Chipping Sodbury, south Gloucestershire, Barnhill Quarry and Chipping Sodbury railway cutting, show differing faunas. Top predators are the large bony fish Severnichthys and the shark Hybodus cloacinus, which preyed on smaller sharks such as Lissodus and Rhomphaiodon. These fishes in turn may have fed on a mixed diet of other fishes and invertebrates, and Lissodus was a shell crusher. Comparisons of these faunas with others described recently from the Bristol region, and from Devon, indicate remarkable faunal similarities in the Rhaetian basal Westbury Formation bone bed over a wide area, based on a variety of ecological statistics that document species diversities and relative abundances. Only the fauna from the Chipping Sodbury railway cutting differs significantly.
Pliosaurs were among the largest predators in Mesozoic seas, and yet their functional anatomy and... more Pliosaurs were among the largest predators in Mesozoic seas, and yet their functional anatomy and feeding biomechanics are poorly understood. A new, well-preserved pliosaur from the Kimmeridgian of Weymouth Bay (UK) revealed cranial adaptations related to feeding. Digital modelling of computed tomography scans allowed reconstruction of missing, distorted regions of the skull and of the adductor musculature, which indicated high bite forces. Size-corrected beam theory modelling showed that the snout was poorly optimised against bending and torsional stresses compared with other aquatic and terrestrial predators, suggesting that pliosaurs did not twist or shake their prey during feeding and that seizing was better performed with post-symphyseal bites. Finite element analysis identified biting-induced stress patterns in both the rostrum and lower jaws, highlighting weak areas in the rostral maxillary-premaxillary contact and the caudal mandibular symphysis. A comparatively weak skull coupled with musculature that was able to produce high forces, is explained as a trade-off between agility, hydrodynamics and strength. In the Kimmeridgian ecosystem, we conclude that Late Jurassic pliosaurs were generalist predators at the top of the food chain, able to prey on reptiles and fishes up to half their own length.
... The teeth of sharks in particular are identifiable to genus and species in many cases (Cuny e... more ... The teeth of sharks in particular are identifiable to genus and species in many cases (Cuny et al., 2004), while teeth of certain ... to survival of bone are carbonate, organic (humate and fluvate) and phosphate species (eg [Johannesson et al., 1996] and [Tang and Johannesson ...
The mass extinction at the Permian-Triassic Boundary (PTB) is said to have been abrupt and probab... more The mass extinction at the Permian-Triassic Boundary (PTB) is said to have been abrupt and probably caused by an extraterrestrial impact. However, evidence from the Global Stratotype Section and Point (GSSP) of the base of the Induan at Meishan, China, shows that the biotic crisis began prior to the level, in beds 25 and 26 at which the postulated impact event occurred. Evidence of such an earlier biotic crisis occurs in other sections in South China, and in central and western Tethyan regions. This event is characterized by the extinction of a range of faunas, including corals, deep-water radiolarians, most fusulinids and pseudotir-olitid ammonoids, and many Permian brachiopods. In all sections, this extinction level is usually a few decimeters to meters below that of the main mass extinction in the event beds (25 and 26) at Meishan, and their correlatives elsewhere. This earlier extinction event happened before the postulated bolide impact at the level of beds 25 and 26, and constrains interpretation of the mechanisms that brought about this greatest mass extinction.
Pliosaurs were a long-lived, ubiquitous group of Mesozoic marine predators attaining large body s... more Pliosaurs were a long-lived, ubiquitous group of Mesozoic marine predators attaining large body sizes (up to 12 m). Despite much being known about their ecology and behaviour, the mechanisms they adopted for prey detection have been poorly investigated and represent a mystery to date. Complex neurovascular systems in many vertebrate rostra have evolved for prey detection. However, information on the occurrence of such systems in fossil taxa is extremely limited because of poor preservation potential. The neurovascular complex from the snout of an exceptionally well-preserved pliosaur from the Kimmeridgian (Late Jurassic, c. 170 Myr ago) of Weymouth Bay (Dorset, UK) is described here for the first time. Using computed tomography (CT) scans, the extensive bifurcating neurovascular channels could be traced through the rostrum to both the teeth and the foramina on the dorsal and lateral surface of the snout. The structures on the surface of the skull and the high concentrations of peripheral rami suggest that this could be a sensory system, perhaps similar to crocodile pressure receptors or shark electroreceptors.
The mass extinction at the Permian-Triassic boundary, 251 million years (Myr) ago, is accepted as... more The mass extinction at the Permian-Triassic boundary, 251 million years (Myr) ago, is accepted as the most profound loss of life on record. Global data compilations indicate a loss of 50% of families or more, both in the sea and on land, and these figures scale to a loss of 80-96% of species, based on rarefaction analyses. This level of loss is confirmed by local and regional-scale studies of marine sections, but the terrestrial record has been harder to analyse in such close detail. Here we document the nature of the event in Russia in a comprehensive survey of 675 specimens of amphibians and reptiles from 289 localities spanning 13 successive geological time zones in the South Urals basin. These changes in diversity and turnover cannot be explained simply by sampling effects. There was a profound loss of genera and families, and simplification of ecosystems, with the loss of small fish-eaters and insect-eaters, medium and large herbivores and large carnivores. Faunal dynamics also changed, from high rates of turnover through the Late Permian period to greater stability at low diversity through the Early Triassic period. Even after 15Myr of ecosystem rebuilding, some guilds were apparently still absent-small fish-eaters, small insect-eaters, large herbivores and top carnivores.
The mass extinction at the Permian-Triassic Boundary (PTB) is said to have been abrupt and probab... more The mass extinction at the Permian-Triassic Boundary (PTB) is said to have been abrupt and probably caused by an extraterrestrial impact. However, evidence from the Global Stratotype Section and Point (GSSP) of the base of the Induan at Meishan, China, shows that the biotic crisis began prior to the level, in beds 25 and 26 at which the postulated impact event occurred. Evidence of such an earlier biotic crisis occurs in other sections in South China, and in central and western Tethyan regions. This event is characterized by the extinction of a range of faunas, including corals, deep-water radiolarians, most fusulinids and pseudotir-olitid ammonoids, and many Permian brachiopods. In all sections, this extinction level is usually a few decimeters to meters below that of the main mass extinction in the event beds (25 and 26) at Meishan, and their correlatives elsewhere. This earlier extinction event happened before the postulated bolide impact at the level of beds 25 and 26, and constrains interpretation of the mechanisms that brought about this greatest mass extinction.
Proceedings of the Geologists' Association, Feb 10, 2015
The Rhaetic Transgression, 210 Myr ago, which marked the end of continental conditions in the
Eu... more The Rhaetic Transgression, 210 Myr ago, which marked the end of continental conditions in the
European Triassic, and the arrival of marine deposition, may have been heralded by the arrival of
burrowing shrimps. Here we document an unusual taphonomic situation, in which classic basal Rhaetic
bone bed is preserved inside a Thalassinoides burrow system at the base of the Westbury Mudstone
Formation, in the highest part of the Blue Anchor Formation, at Charton Bay, Devon, UK. The fauna
comprises four species of sharks and five species of bony fishes. The sharks, Rhomphaiodon (‘Hybodus’),
Duffinselache, Lissodus, and Pseudocetorhinus are small, and include predatory and crushing/
opportunistic feeders. The top predator was the large Severnichthys, typical of Rhaetian ichthyofaunas,
and Gyrolepis was a smaller predator. Late Triassic bony fishes generally included many shell-crushers,
and the Charton Bay assemblage is no exception, with teeth of Sargodon, ‘Lepidotes’, and Dapedium, the
last being a rare record for the British Rhaetic. This kind of burrowed and filled contact occurs elsewhere
at the base of the Westbury Mudstone Formation, and so may be a typical marker of the early phases of
the Rhaetic Transgression.
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Papers by Mike Benton
Sodbury railway cutting, show differing faunas. Top predators are the large bony fish Severnichthys and the shark Hybodus cloacinus, which preyed on smaller sharks such as Lissodus and Rhomphaiodon. These fishes in turn may have fed on a mixed diet of other fishes and invertebrates, and Lissodus was a shell crusher. Comparisons of these faunas with others described recently from the Bristol region, and from Devon, indicate remarkable faunal similarities in the Rhaetian basal Westbury Formation bone bed over a wide area, based on a variety of ecological statistics that document species diversities and relative abundances. Only the fauna from the Chipping Sodbury railway cutting differs significantly.
Sodbury railway cutting, show differing faunas. Top predators are the large bony fish Severnichthys and the shark Hybodus cloacinus, which preyed on smaller sharks such as Lissodus and Rhomphaiodon. These fishes in turn may have fed on a mixed diet of other fishes and invertebrates, and Lissodus was a shell crusher. Comparisons of these faunas with others described recently from the Bristol region, and from Devon, indicate remarkable faunal similarities in the Rhaetian basal Westbury Formation bone bed over a wide area, based on a variety of ecological statistics that document species diversities and relative abundances. Only the fauna from the Chipping Sodbury railway cutting differs significantly.
European Triassic, and the arrival of marine deposition, may have been heralded by the arrival of
burrowing shrimps. Here we document an unusual taphonomic situation, in which classic basal Rhaetic
bone bed is preserved inside a Thalassinoides burrow system at the base of the Westbury Mudstone
Formation, in the highest part of the Blue Anchor Formation, at Charton Bay, Devon, UK. The fauna
comprises four species of sharks and five species of bony fishes. The sharks, Rhomphaiodon (‘Hybodus’),
Duffinselache, Lissodus, and Pseudocetorhinus are small, and include predatory and crushing/
opportunistic feeders. The top predator was the large Severnichthys, typical of Rhaetian ichthyofaunas,
and Gyrolepis was a smaller predator. Late Triassic bony fishes generally included many shell-crushers,
and the Charton Bay assemblage is no exception, with teeth of Sargodon, ‘Lepidotes’, and Dapedium, the
last being a rare record for the British Rhaetic. This kind of burrowed and filled contact occurs elsewhere
at the base of the Westbury Mudstone Formation, and so may be a typical marker of the early phases of
the Rhaetic Transgression.
Sodbury railway cutting, show differing faunas. Top predators are the large bony fish Severnichthys and the shark Hybodus cloacinus, which preyed on smaller sharks such as Lissodus and Rhomphaiodon. These fishes in turn may have fed on a mixed diet of other fishes and invertebrates, and Lissodus was a shell crusher. Comparisons of these faunas with others described recently from the Bristol region, and from Devon, indicate remarkable faunal similarities in the Rhaetian basal Westbury Formation bone bed over a wide area, based on a variety of ecological statistics that document species diversities and relative abundances. Only the fauna from the Chipping Sodbury railway cutting differs significantly.
Sodbury railway cutting, show differing faunas. Top predators are the large bony fish Severnichthys and the shark Hybodus cloacinus, which preyed on smaller sharks such as Lissodus and Rhomphaiodon. These fishes in turn may have fed on a mixed diet of other fishes and invertebrates, and Lissodus was a shell crusher. Comparisons of these faunas with others described recently from the Bristol region, and from Devon, indicate remarkable faunal similarities in the Rhaetian basal Westbury Formation bone bed over a wide area, based on a variety of ecological statistics that document species diversities and relative abundances. Only the fauna from the Chipping Sodbury railway cutting differs significantly.
European Triassic, and the arrival of marine deposition, may have been heralded by the arrival of
burrowing shrimps. Here we document an unusual taphonomic situation, in which classic basal Rhaetic
bone bed is preserved inside a Thalassinoides burrow system at the base of the Westbury Mudstone
Formation, in the highest part of the Blue Anchor Formation, at Charton Bay, Devon, UK. The fauna
comprises four species of sharks and five species of bony fishes. The sharks, Rhomphaiodon (‘Hybodus’),
Duffinselache, Lissodus, and Pseudocetorhinus are small, and include predatory and crushing/
opportunistic feeders. The top predator was the large Severnichthys, typical of Rhaetian ichthyofaunas,
and Gyrolepis was a smaller predator. Late Triassic bony fishes generally included many shell-crushers,
and the Charton Bay assemblage is no exception, with teeth of Sargodon, ‘Lepidotes’, and Dapedium, the
last being a rare record for the British Rhaetic. This kind of burrowed and filled contact occurs elsewhere
at the base of the Westbury Mudstone Formation, and so may be a typical marker of the early phases of
the Rhaetic Transgression.