Conference Presentations by Stu Pond
Introduction
Dinosaur tracks and traces have been known from strata on the Isle of Wight (off th... more Introduction
Dinosaur tracks and traces have been known from strata on the Isle of Wight (off the south coast of England) since the late 19th Century (Martill and Naish, 2001). Here, early Cretaceous (late Barremian - early Aptian) strata of the Wealden Group are famous for the fossil remains of dinosaurs, including footprints assigned to a number of different taxa. Described traces from the Island include those interpreted as having been left behind by medium-to-large sized ornithopods and small-to-medium sized theropods as well as the possible tracks of sauropods. All of these taxa are known from the Island on the basis of their skeletal remains.
Here, we augment the dinosaur tracks known from the Isle-of-Wight by presenting a large collection of footprints all collected by one of us (DD) from the Vectis Formation, exposed on the southern coast of the Island (Radley et al., 1998). Our ongoing work allows, for the first time, a comprehensive review of the dinosaur ichnoassociations known from the Isle-of-Wight.
Geological setting
Although the precise stratigraphical location of the DD footprint site is not reported here, all the specimens come from Diplocraterion Bed 1 (Radley et al., 1998), within the widespread Vectis Formation. On the island, this formation can be up to 80 metres in thickness (within the Wealden Group of sediments), and comprises (for the most part) a series of mudstone-dominated cycles deposited in coastal lagoonal settings. Sediment viscosity of this type and sedimentary environment is thought ideal for the preservation of footprints (Falkingham et al., 2011). Currently, the best footprint localities on the southern coast of the Isle-of-Wight are exposed only at very long spring tides.
Material and methods
10 dinosaur footprints from a much larger recovered sample are noted here, referred to using DD_numbers following the discoverer’s initials. All are preserved as natural casts; according to Radley et al. (1998) and Goldring et al. (2005) footprints were first impressed onto a muddy layer and then infilled later by sand-grade bioclastic sediment packed with the gastropod Viviparus and the rarer bivalve Filosina (Fig. 1). An overlaid tabular layer (seen, for example, in specimens DD 01 and DD 06) is also present and is dominated by convex-up disarticulated Filosina shells.
Footprint preservation is generally very poor with few morphological details preserved apart from digits.
10 tracks in the DD collection were photographed by SP in February 2012. Descriptions and measurements were made following the suggestions of Leonardi (1987).
These pictures, taken with a Fujifilm S8000fd, 8 million pixel camera, are all of footprint dorsal surfaces and were processed by MB with Agisoft Photoscan Pro (v. 0.8.4). This allowed fair 3D models to be generated, although the lack of angled photos has led to several incomplete-to-voided regions. Resulting models are nevertheless good enough to allow us to generate colour-coded maps of footprint depths (Fig. 2) as well as contour lines using ParaView (v. 3.14). Measurements of tracks were then made directly using meshes generated in Polyworks (v. 10.0) following the procedures applied and tested in Belvedere et al. (2010).
Track description and interpretation
The ichnological interpretations presented here are based on incomplete 3D models and thus must be considered preliminary.
DD_01. This track (Fig. 2, A-B) is longer (16 cm) than wide (11 cm), roughly bell-shaped and with its anterior part larger than the posterior. Three possible digits are present, short and rounded with no claw impressions. The deepest part is located in the middle of the track, but this preservation could be due to recent erosion. The three blunt toes, together with the general shape of the track, allow us to identify this print as a possible Deltapodus (Romano and Whyte, 1995).
DD_02. This tridactyl track is roughly as long (13 cm) as wide (11 cm), with short rounded digits and interdigital angles that are symmetrical. Its short blunt digits and symmetrical interdigital angles suggest an ornithopod trackmaker, but preservation prevents a more detailed interpretation.
DD_03. This footprint is slightly longer (18 cm) than wide (17 cm), is asymmetrical (II^III < III^IV) and with digit III probably the longest. All digits are slender with tapering terminations; no pads or claw mark impressions are preserved. These morphological features allow us to identify this footprint (with a reasonable degree of certainty) as a theropod track.
DD_04. This trace (Fig. 2, C-D) is one of the most ambiguous recovered. At first glance, from the photo (Fig. 2 E), it might be considered to be from a sauropod manus, whereas based on the 3D model (Fig. 2 F) it is possible to see three clear digits, with probable digit I and metatarsal impressions. As in DD_01, the maximum depth of this track is around the middle of the print and is thus probably a result of recent erosion. This print is longer (17 cm) than it is wide (13 cm) and is slightly asymmetrical (II^III < III^IV). No further information is available, but it is identified here as a probable theropod footprint.
Tracks from DD_05 to DD_08 present no clear pad impresssions or claw marks and all have similar morphological charactersitics: slender digits with tapering terminations, asymmetric interdigital angles (II^III < III^IV), athough all are slightly different sizes (see Table 1). All these preserved features allow us to identify them as theropod tracks.
DD_09. The preservation of this footprint is quite poor and morphological characteristics are barely identifiable. However, two digits are visible while the third is not well preserved. The footprint is slightly longer (22 cm) than wide (19 cm), and almost symmetrical; the digits are blunt and short probably because of erosion.
DD_10. As is the case for DD_09, the preservation of this footprint is very poor but it is possible to clearly recognise two rounded digits while a third is only partially preserved (Fig. 2, G-H). This footprint is longer (23 cm) than wide (21 cm) and has slightly asymmetrical intergitial angles. Although a clear identification for DD_09 and DD_10 is not possible, symmetry in the interdigital angles and the short digits allows to suppose an probable ornithopod trackmaker.
Although very preliminary and based on few prints, this study increases our baseline knowledge of Isle of Wight dinosaurs and highlights the potential of ichnological analyses which will provide more detailed palaeobiological data in the future.
References
BELVEDERE, M., MIETTO, P. and ISHIGAKI, S. 2010. A Late Jurassic diverse ichnocoenosis from the siliciclastic Iouaridène Formation (Central High Atlas, Morocco). Geological Quarterly, 54: 367–380.
FALKINGHAM, P. L., BATES, K. T., MARGETTS L., and MANNING, P. L. 2011. The 'Goldilocks' effect: preservation bias in vertebrate track assemblages. Journal of the Royal Society: Interface, 8: 1142-1154.
GOLDRING, R., POLLARD, J. E. and RADLEY, J. D. 2005. Trace fossils and pseudofossils from the Wealden strata (non-marine Lower Cretaceous) of southern England. Cretaceous Research, 26: 665-685.
LEONARDI, G. 1987. Glossary and manual of tetrapod footprint palaeoichnology. Publicação do Departemento Nacional da Produção Mineral Brasil. Brasíli, 117 p.
MARTILL, D. M. and NAISH, D. 2001. Dinosaurs of the Isle of Wight. Palaeontological Association, London, 433 p.
RADLEY, J. D., BARKER, M. J. and HARDING, I. C. 1998. Palaeoenvironment and taphonomy of dinosaur tracks in the Vectis Formation (Lower Cretaceous) of the Wessex Sub-basin, southern England. Cretaceous Research, 19: 471-487.
WHYTE, M. A. and ROMANO, M. 1994. Probable sauropod footprints from the Middle Jurassic of Yorkshire. Gaia, 10: 15-26.
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Papers by Stu Pond
Journal of Systematic Palaeontology, 2023
The Wealden Group of southern England was deposited by rivers, on floodplains and in lagoons duri... more The Wealden Group of southern England was deposited by rivers, on floodplains and in lagoons during the Early Cretaceous. Two historically significant ankylosaurs, Polacanthus and Hylaeosaurus, are currently known from its deposits; Hylaeosaurus from the 'lower Wealden fauna' and Polacanthus from the 'upper Wealden fauna'. Here, we describe a new genus and species of ankylosaur from the Wessex Formation of the Isle of Wight, which is characterized by numerous postcranial autapomorphies. Vectipelta barretti gen. et sp. nov. is 6-8 million years older than Polacanthus, and at least 3 million years younger than Hylaeosaurus, suggesting a more complicated pattern of faunal turnover in the Wealden Group than previously realized. Vectipelta does not appear to be closely related to either of the other Wealden taxa, but instead is found in a clade with two Chinese ankylosaurs, suggesting a complex pattern of dispersal to and from Europe, North America and Asia during the Early Cretaceous. The historic practise of cataloguing all ankylosaur material from the Wessex Formation as 'Polacanthus' has potentially prevented a diversity of taxa from being discovered, and new and existing material in museum collections should be re-appraised using an autapomorphy-driven approach.
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Biological Journal of the Linnean Society, 2014
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Biological Journal of the Linnean Society, 2014
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Introduction Dinosaur tracks and traces have been known from strata on the Isle of Wight (off the... more Introduction Dinosaur tracks and traces have been known from strata on the Isle of Wight (off the south coast of England) since the late 19th Century (Martill and Naish, 2001). Here, early Cretaceous (late Barremian - early Aptian) strata of the Wealden Group are famous for the fossil remains of dinosaurs, including footprints assigned to a number of different taxa. Described traces from the Island include those interpreted as having been left behind by medium-to-large sized ornithopods and small-to-medium sized theropods as well as the possible tracks of sauropods. All of these taxa are known from the Island on the basis of their skeletal remains. Here, we augment the dinosaur tracks known from the Isle-of-Wight by presenting a large collection of footprints all collected by one of us (DD) from the Vectis Formation, exposed on the southern coast of the Island (Radley et al., 1998). Our ongoing work allows, for the first time, a comprehensive review of the dinosaur ichnoassociations known from the Isle-of-Wight. Geological setting Although the precise stratigraphical location of the DD footprint site is not reported here, all the specimens come from Diplocraterion Bed 1 (Radley et al., 1998), within the widespread Vectis Formation. On the island, this formation can be up to 80 metres in thickness (within the Wealden Group of sediments), and comprises (for the most part) a series of mudstone-dominated cycles deposited in coastal lagoonal settings. Sediment viscosity of this type and sedimentary environment is thought ideal for the preservation of footprints (Falkingham et al., 2011). Currently, the best footprint localities on the southern coast of the Isle-of-Wight are exposed only at very long spring tides. Material and methods 10 dinosaur footprints from a much larger recovered sample are noted here, referred to using DD_numbers following the discoverer’s initials. All are preserved as natural casts; according to Radley et al. (1998) and Goldring et al. (2005) footprints were first impressed onto a muddy layer and then infilled later by sand-grade bioclastic sediment packed with the gastropod Viviparus and the rarer bivalve Filosina (Fig. 1). An overlaid tabular layer (seen, for example, in specimens DD 01 and DD 06) is also present and is dominated by convex-up disarticulated Filosina shells. Footprint preservation is generally very poor with few morphological details preserved apart from digits. 10 tracks in the DD collection were photographed by SP in February 2012. Descriptions and measurements were made following the suggestions of Leonardi (1987). These pictures, taken with a Fujifilm S8000fd, 8 million pixel camera, are all of footprint dorsal surfaces and were processed by MB with Agisoft Photoscan Pro (v. 0.8.4). This allowed fair 3D models to be generated, although the lack of angled photos has led to several incomplete-to-voided regions. Resulting models are nevertheless good enough to allow us to generate colour-coded maps of footprint depths (Fig. 2) as well as contour lines using ParaView (v. 3.14). Measurements of tracks were then made directly using meshes generated in Polyworks (v. 10.0) following the procedures applied and tested in Belvedere et al. (2010). Track description and interpretation The ichnological interpretations presented here are based on incomplete 3D models and thus must be considered preliminary. DD_01. This track (Fig. 2, A-B) is longer (16 cm) than wide (11 cm), roughly bell-shaped and with its anterior part larger than the posterior. Three possible digits are present, short and rounded with no claw impressions. The deepest part is located in the middle of the track, but this preservation could be due to recent erosion. The three blunt toes, together with the general shape of the track, allow us to identify this print as a possible Deltapodus (Romano and Whyte, 1995). DD_02. This tridactyl track is roughly as long (13 cm) as wide (11 cm), with short rounded digits and interdigital angles that are symmetrical. Its short blunt digits and symmetrical interdigital angles suggest an ornithopod trackmaker, but preservation prevents a more detailed interpretation. DD_03. This footprint is slightly longer (18 cm) than wide (17 cm), is asymmetrical (II^III < III^IV) and with digit III probably the longest. All digits are slender with tapering terminations; no pads or claw mark impressions are preserved. These morphological features allow us to identify this footprint (with a reasonable degree of certainty) as a theropod track. DD_04. This trace (Fig. 2, C-D) is one of the most ambiguous recovered. At first glance, from the photo (Fig. 2 E), it might be considered to be from a sauropod manus, whereas based on the 3D model (Fig. 2 F) it is possible to see three clear digits, with probable digit I and metatarsal impressions. As in DD_01, the maximum depth of this track is around the middle of the print and is thus probably a result of recent erosion. This print is longer (17 cm)…
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Biological Journal of the Linnean Society, 2014
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Dinosaurs are a source of enormous public interest and as such are useful for fostering greater i... more Dinosaurs are a source of enormous public interest and as such are useful for fostering greater interest in basic science and technology. With the increasing popularity of dinosaur films that claim to portray realistic dinosaur behaviour, one question that is regularly posed for palaeontologists to answer is how we know that our reconstructions are accurate. Dinosaur locomotion is no exception to this line of questioning and one technique for estimating how dinosaurs may have moved is multibody dynamic simulation (MBDA) of high biofidelity musculoskeletal computer models. Such simulations uses Newton's Law's of Motion to calculate how the different parts of the animals body would have moved depending on the internal forces generated by the muscles and the external forces due to gravity and physical contact with the ground. In this project we designed a system that allowed the user to directly control the muscles forces generated using a Kinect for Xbox One sensor attached to...
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Triassic vertebrate tracks have been described from several localities in the Burton upon Trent a... more Triassic vertebrate tracks have been described from several localities in the Burton upon Trent area. The National Brewery Centre Museum in Burton upon Trent holds two slabs showing tracks attributed to Chirotherium from a find at Ashby Road in 1912. A natural cast of a print from the same excavation is in a private collection. Slabs bearing Rhynchosauroides prints that were purchased by the Natural History Museum in 1848 and 1858 were erroneously listed as coming from ‘Staunton’ but were actually found at Stanton, close to Burton upon Trent and about 2 km from the Ashby Road finds. Within this ichnoassemblage, the Ashby Road tracks are assigned to Chirotherium cf. barthii and the Stanton tracks to Rhynchosauroides rectipes and Rotodactylus isp. The Chirotherium tracks have an unusually large digit II and manus. Photogrammetry has been used to enhance details of the Chirotherium specimens. The outcrops adjacent to the eastern end of the old Trent Bridge (Fig. 1) in Burton upon Trent...
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PeerJ, 2017
The running ability of Tyrannosaurus rex has been intensively studied due to its relevance to int... more The running ability of Tyrannosaurus rex has been intensively studied due to its relevance to interpretations of feeding behaviour and the biomechanics of scaling in giant predatory dinosaurs. Different studies using differing methodologies have produced a very wide range of top speed estimates and there is therefore a need to develop techniques that can improve these predictions. Here we present a new approach that combines two separate biomechanical techniques (multibody dynamic analysis and skeletal stress analysis) to demonstrate that true running gaits would probably lead to unacceptably high skeletal loads in T. rex. Combining these two approaches reduces the high-level of uncertainty in previous predictions associated with unknown soft tissue parameters in dinosaurs, and demonstrates that the relatively long limb segments of T. rex-long argued to indicate competent running ability-would actually have mechanically limited this species to walking gaits. Being limited to walking...
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Journal of Vertebrate Paleontology
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Ankylosaur remains are frequently recovered from the Lower Cretaceous Wealden deposits of the Isl... more Ankylosaur remains are frequently recovered from the Lower Cretaceous Wealden deposits of the Isle of Wight, although the vast majority of these fossils represent postcranial elements and osteoderms. The rarity of ankylosaur cranial material means any new specimens are important for understanding the morphology, palaeoecology and evolution of these taxa. Here we describe a well-preserved partial ankylosaur cranium recovered with associated ankylosaur remains from the Wessex Formation at Compton Bay. This is the most complete ankylosaur skull ever recovered from the Wessex Sub-basin and is now held at Dinosaur Isle Museum (DI), Sandown, IOW. A highly water worn specimen held at the Sedgwick Museum of Earth Sciences was found at Chilton Chine in the early 1990s and assigned to cf. Polacanthus, and the two crania are compared here. The specimen consists of the posterior part of the basicranium and skull roof including the proximal paraoccipital processes, occipital condyle and basal tu...
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The running ability of Tyrannosaurus rex has been intensively studied due to its relevance to int... more The running ability of Tyrannosaurus rex has been intensively studied due to its relevance to interpretations of feeding behaviour and the biomechanics of scaling in giant predatory dinosaurs. Different studies using differing methodologies have produced a very wide range of top speed estimates and there is therefore a need to develop techniques that can improve these predictions. Here we present a new approach that combines two separate biomechanical techniques (multibody dynamic analysis and skeletal stress analysis) to demonstrate that true running gaits would probably lead to unacceptably high skeletal loads in T. rex. Combining these two approaches reduces the high-level of uncertainty in previous predictions associated with unknown soft tissue parameters in dinosaurs, and demonstrates that the relatively long limb segments of T. rexlong argued to indicate competent running abilitywould actually have mechanically limited this species to walking gaits. Being limited to walking speeds contradicts arguments of high-speed pursuit predation for the largest bipedal dinosaurs like T. rex, and demonstrates the power of multiphysics approaches for locomotor reconstructions of extinct animals.
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Hanover Point on the Isle of Wight, England, is a Lower Cretaceous (Barremian) site yielding a la... more Hanover Point on the Isle of Wight, England, is a Lower Cretaceous (Barremian) site yielding a large number of dinosaur footprints from the Wessex Formation. These footprints, hitherto often referred to as 'Iguanodon' tracks, have generated interest and speculation since the beginning of the Victorian era. Today, Hanover Point largely yields sandstone casts (convex hyporeliefs) of footprints but also includes some impressions (concave epireliefs), a few of which form short trackways. The majority belongs to large ornithopods, many with foot lengths in excess of 50 cm. Theropods and the occasional thyreophoran track are also represented. The site represents the Wessex Formation within the Wealden Group and can be described ichnologically as a category 3a deposit. Most of the large ornithopod footprints have a distinctive quadripartite morphology and are best assigned to the ichnogenus Caririchnium or in some cases Amblydactylus. Few are morphologically compatible with Iguanodontipus which was described from pre-Wealden deposits and appears to be little represented in the Wealden ichnofaunas.
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Biological Journal of the Linnean Society, 2014
ABSTRACT Trackways of ornithopods are well-known from the Lower Cretaceous of Europe, North Ameri... more ABSTRACT Trackways of ornithopods are well-known from the Lower Cretaceous of Europe, North America, and East Asia. For historical reasons, most large ornithopod footprints are associated with the genus Iguanodon or, more generally, with the family Iguanodontidae. Moreover, this general category of footprints is considered to be sufficiently dominant at this time as to characterize a global Early Cretaceous biochron. However, six valid ornithopod ichnogenera have been named from the Cretaceous, including several that are represented by multiple ichnospecies: these are Amblydactylus (two ichnospecies); Caririchnium (four ichnospecies); Iguanodontipus, Ornithopodichnus originally named from Lower Cretaceous deposits and Hadrosauropodus (two ichnospecies); and Jiayinosauropus based on Upper Cretaceous tracks. It has recently been suggested that ornithopod ichnotaxonomy is oversplit and that Caririchnium is a senior subjective synonym of Hadrosauropodus and Amblydactylus is a senior subjective synonym of Iguanodontipus. Although it is agreed that many ornithopod tracks are difficult to differentiate, this proposed synonymy is questionable because it was not based on a detailed study of the holotypes, and did not consider all valid ornithopod ichnotaxa or the variation reported within the six named ichnogenera and 11 named ichnospecies reviewed here. We therefore emphasize the need to base comparisons between ichnotaxa on type material, and not on selected referred material. It is concluded that there is considerable variation in the morphology of the holotypes, as well as variation in size and quality of the samples and the mode of preservation. Conversely, there is considerable overlap in morphology among other tracks that have been informally attributed to these ichnotaxa. These factors make it difficult to synonymize any of the existing ichnotaxa without detailed revision of the samples from which the type material originates. Nevertheless, a review of the type material of all ichnotaxa is presented as a basis for further discussion and, as a first step, the ichnofamily Iguanodontipodidae is proposed to accommodate Amblydactylus, Caririchnium and Iguanodontipus, © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 721–736.
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The Wealden exposures on the Isle of Wight have long been noted for their dinosaur footprints and... more The Wealden exposures on the Isle of Wight have long been noted for their dinosaur footprints and trackways and
represent a unique ichnological resource. However, with a few notable exceptions, these ichnites remain largely
unstudied and documentation has been sporadic and often concentrated on a few particular sites. Thus, their
context within the Lower Cretaceous is poorly understood. The vertebrate ichnological record of the Wessex
Sub-basin is currently being re-assessed. We review the main sites containing dinosaur footprints on the Isle of
Wight. We also look at previously-known sites, and present new research using techniques such as photogrammetry
to accurately record, preserve, and distribute ichnological data, especially data recorded in the dynamic foreshore
and cliff environments, where many trace fossils are frequently lost as a result of human activity, weathering,
erosion, and changing marine dynamics. Although the ichnoassemblages of the island’s Wealden facies are
dominated by ornithopod tracks including Caririchnium and Amblydactylus, we also report the first occurrence of
the ankylosaurian track Tetrapodosaurus in both the Wessex and Vectis Formations, alongside the previously
reported stegosaurian Deltapodus, as well as the occurrence of tracks left by saurichian tracemakers. © 2014 The
Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 737–757.
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Triassic vertebrate tracks have been described from several localities in the Burton upon Trent a... more Triassic vertebrate tracks have been described from several localities in the Burton upon Trent area. The National Brewery Centre Museum (formerly the Bass Museum) in Burton on Trent hold two slabs showing tracks attributed to Chirotherium from a find at Ashby Road in 1912. A natural cast of a print from the same excavation is in a private collection.
Slabs bearing Rhynchosauroides prints that were purchased by the Natural History Museum in 1848 and 1858 were erroneously listed as coming from ‘Staunton’ but were actually found at Stanton, close to Burton on Trent and about 2km from the Ashby Road finds.
The history of these finds is detailed together with a review of the geology and significance of this ichnoassemblage. The Ashby Road tracks are assigned to Chirotherium cf. barthii and the Stanton tracks to Rhynchosauroides rectipes and Rotodactylus isp. The Chirotherium tracks have an unusually large digit II and manus.
Photogrammetric methods have been used to enhance details of the Chirotherium specimens.
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Conference Presentations by Stu Pond
Dinosaur tracks and traces have been known from strata on the Isle of Wight (off the south coast of England) since the late 19th Century (Martill and Naish, 2001). Here, early Cretaceous (late Barremian - early Aptian) strata of the Wealden Group are famous for the fossil remains of dinosaurs, including footprints assigned to a number of different taxa. Described traces from the Island include those interpreted as having been left behind by medium-to-large sized ornithopods and small-to-medium sized theropods as well as the possible tracks of sauropods. All of these taxa are known from the Island on the basis of their skeletal remains.
Here, we augment the dinosaur tracks known from the Isle-of-Wight by presenting a large collection of footprints all collected by one of us (DD) from the Vectis Formation, exposed on the southern coast of the Island (Radley et al., 1998). Our ongoing work allows, for the first time, a comprehensive review of the dinosaur ichnoassociations known from the Isle-of-Wight.
Geological setting
Although the precise stratigraphical location of the DD footprint site is not reported here, all the specimens come from Diplocraterion Bed 1 (Radley et al., 1998), within the widespread Vectis Formation. On the island, this formation can be up to 80 metres in thickness (within the Wealden Group of sediments), and comprises (for the most part) a series of mudstone-dominated cycles deposited in coastal lagoonal settings. Sediment viscosity of this type and sedimentary environment is thought ideal for the preservation of footprints (Falkingham et al., 2011). Currently, the best footprint localities on the southern coast of the Isle-of-Wight are exposed only at very long spring tides.
Material and methods
10 dinosaur footprints from a much larger recovered sample are noted here, referred to using DD_numbers following the discoverer’s initials. All are preserved as natural casts; according to Radley et al. (1998) and Goldring et al. (2005) footprints were first impressed onto a muddy layer and then infilled later by sand-grade bioclastic sediment packed with the gastropod Viviparus and the rarer bivalve Filosina (Fig. 1). An overlaid tabular layer (seen, for example, in specimens DD 01 and DD 06) is also present and is dominated by convex-up disarticulated Filosina shells.
Footprint preservation is generally very poor with few morphological details preserved apart from digits.
10 tracks in the DD collection were photographed by SP in February 2012. Descriptions and measurements were made following the suggestions of Leonardi (1987).
These pictures, taken with a Fujifilm S8000fd, 8 million pixel camera, are all of footprint dorsal surfaces and were processed by MB with Agisoft Photoscan Pro (v. 0.8.4). This allowed fair 3D models to be generated, although the lack of angled photos has led to several incomplete-to-voided regions. Resulting models are nevertheless good enough to allow us to generate colour-coded maps of footprint depths (Fig. 2) as well as contour lines using ParaView (v. 3.14). Measurements of tracks were then made directly using meshes generated in Polyworks (v. 10.0) following the procedures applied and tested in Belvedere et al. (2010).
Track description and interpretation
The ichnological interpretations presented here are based on incomplete 3D models and thus must be considered preliminary.
DD_01. This track (Fig. 2, A-B) is longer (16 cm) than wide (11 cm), roughly bell-shaped and with its anterior part larger than the posterior. Three possible digits are present, short and rounded with no claw impressions. The deepest part is located in the middle of the track, but this preservation could be due to recent erosion. The three blunt toes, together with the general shape of the track, allow us to identify this print as a possible Deltapodus (Romano and Whyte, 1995).
DD_02. This tridactyl track is roughly as long (13 cm) as wide (11 cm), with short rounded digits and interdigital angles that are symmetrical. Its short blunt digits and symmetrical interdigital angles suggest an ornithopod trackmaker, but preservation prevents a more detailed interpretation.
DD_03. This footprint is slightly longer (18 cm) than wide (17 cm), is asymmetrical (II^III < III^IV) and with digit III probably the longest. All digits are slender with tapering terminations; no pads or claw mark impressions are preserved. These morphological features allow us to identify this footprint (with a reasonable degree of certainty) as a theropod track.
DD_04. This trace (Fig. 2, C-D) is one of the most ambiguous recovered. At first glance, from the photo (Fig. 2 E), it might be considered to be from a sauropod manus, whereas based on the 3D model (Fig. 2 F) it is possible to see three clear digits, with probable digit I and metatarsal impressions. As in DD_01, the maximum depth of this track is around the middle of the print and is thus probably a result of recent erosion. This print is longer (17 cm) than it is wide (13 cm) and is slightly asymmetrical (II^III < III^IV). No further information is available, but it is identified here as a probable theropod footprint.
Tracks from DD_05 to DD_08 present no clear pad impresssions or claw marks and all have similar morphological charactersitics: slender digits with tapering terminations, asymmetric interdigital angles (II^III < III^IV), athough all are slightly different sizes (see Table 1). All these preserved features allow us to identify them as theropod tracks.
DD_09. The preservation of this footprint is quite poor and morphological characteristics are barely identifiable. However, two digits are visible while the third is not well preserved. The footprint is slightly longer (22 cm) than wide (19 cm), and almost symmetrical; the digits are blunt and short probably because of erosion.
DD_10. As is the case for DD_09, the preservation of this footprint is very poor but it is possible to clearly recognise two rounded digits while a third is only partially preserved (Fig. 2, G-H). This footprint is longer (23 cm) than wide (21 cm) and has slightly asymmetrical intergitial angles. Although a clear identification for DD_09 and DD_10 is not possible, symmetry in the interdigital angles and the short digits allows to suppose an probable ornithopod trackmaker.
Although very preliminary and based on few prints, this study increases our baseline knowledge of Isle of Wight dinosaurs and highlights the potential of ichnological analyses which will provide more detailed palaeobiological data in the future.
References
BELVEDERE, M., MIETTO, P. and ISHIGAKI, S. 2010. A Late Jurassic diverse ichnocoenosis from the siliciclastic Iouaridène Formation (Central High Atlas, Morocco). Geological Quarterly, 54: 367–380.
FALKINGHAM, P. L., BATES, K. T., MARGETTS L., and MANNING, P. L. 2011. The 'Goldilocks' effect: preservation bias in vertebrate track assemblages. Journal of the Royal Society: Interface, 8: 1142-1154.
GOLDRING, R., POLLARD, J. E. and RADLEY, J. D. 2005. Trace fossils and pseudofossils from the Wealden strata (non-marine Lower Cretaceous) of southern England. Cretaceous Research, 26: 665-685.
LEONARDI, G. 1987. Glossary and manual of tetrapod footprint palaeoichnology. Publicação do Departemento Nacional da Produção Mineral Brasil. Brasíli, 117 p.
MARTILL, D. M. and NAISH, D. 2001. Dinosaurs of the Isle of Wight. Palaeontological Association, London, 433 p.
RADLEY, J. D., BARKER, M. J. and HARDING, I. C. 1998. Palaeoenvironment and taphonomy of dinosaur tracks in the Vectis Formation (Lower Cretaceous) of the Wessex Sub-basin, southern England. Cretaceous Research, 19: 471-487.
WHYTE, M. A. and ROMANO, M. 1994. Probable sauropod footprints from the Middle Jurassic of Yorkshire. Gaia, 10: 15-26.
Papers by Stu Pond
represent a unique ichnological resource. However, with a few notable exceptions, these ichnites remain largely
unstudied and documentation has been sporadic and often concentrated on a few particular sites. Thus, their
context within the Lower Cretaceous is poorly understood. The vertebrate ichnological record of the Wessex
Sub-basin is currently being re-assessed. We review the main sites containing dinosaur footprints on the Isle of
Wight. We also look at previously-known sites, and present new research using techniques such as photogrammetry
to accurately record, preserve, and distribute ichnological data, especially data recorded in the dynamic foreshore
and cliff environments, where many trace fossils are frequently lost as a result of human activity, weathering,
erosion, and changing marine dynamics. Although the ichnoassemblages of the island’s Wealden facies are
dominated by ornithopod tracks including Caririchnium and Amblydactylus, we also report the first occurrence of
the ankylosaurian track Tetrapodosaurus in both the Wessex and Vectis Formations, alongside the previously
reported stegosaurian Deltapodus, as well as the occurrence of tracks left by saurichian tracemakers. © 2014 The
Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 737–757.
Slabs bearing Rhynchosauroides prints that were purchased by the Natural History Museum in 1848 and 1858 were erroneously listed as coming from ‘Staunton’ but were actually found at Stanton, close to Burton on Trent and about 2km from the Ashby Road finds.
The history of these finds is detailed together with a review of the geology and significance of this ichnoassemblage. The Ashby Road tracks are assigned to Chirotherium cf. barthii and the Stanton tracks to Rhynchosauroides rectipes and Rotodactylus isp. The Chirotherium tracks have an unusually large digit II and manus.
Photogrammetric methods have been used to enhance details of the Chirotherium specimens.
Dinosaur tracks and traces have been known from strata on the Isle of Wight (off the south coast of England) since the late 19th Century (Martill and Naish, 2001). Here, early Cretaceous (late Barremian - early Aptian) strata of the Wealden Group are famous for the fossil remains of dinosaurs, including footprints assigned to a number of different taxa. Described traces from the Island include those interpreted as having been left behind by medium-to-large sized ornithopods and small-to-medium sized theropods as well as the possible tracks of sauropods. All of these taxa are known from the Island on the basis of their skeletal remains.
Here, we augment the dinosaur tracks known from the Isle-of-Wight by presenting a large collection of footprints all collected by one of us (DD) from the Vectis Formation, exposed on the southern coast of the Island (Radley et al., 1998). Our ongoing work allows, for the first time, a comprehensive review of the dinosaur ichnoassociations known from the Isle-of-Wight.
Geological setting
Although the precise stratigraphical location of the DD footprint site is not reported here, all the specimens come from Diplocraterion Bed 1 (Radley et al., 1998), within the widespread Vectis Formation. On the island, this formation can be up to 80 metres in thickness (within the Wealden Group of sediments), and comprises (for the most part) a series of mudstone-dominated cycles deposited in coastal lagoonal settings. Sediment viscosity of this type and sedimentary environment is thought ideal for the preservation of footprints (Falkingham et al., 2011). Currently, the best footprint localities on the southern coast of the Isle-of-Wight are exposed only at very long spring tides.
Material and methods
10 dinosaur footprints from a much larger recovered sample are noted here, referred to using DD_numbers following the discoverer’s initials. All are preserved as natural casts; according to Radley et al. (1998) and Goldring et al. (2005) footprints were first impressed onto a muddy layer and then infilled later by sand-grade bioclastic sediment packed with the gastropod Viviparus and the rarer bivalve Filosina (Fig. 1). An overlaid tabular layer (seen, for example, in specimens DD 01 and DD 06) is also present and is dominated by convex-up disarticulated Filosina shells.
Footprint preservation is generally very poor with few morphological details preserved apart from digits.
10 tracks in the DD collection were photographed by SP in February 2012. Descriptions and measurements were made following the suggestions of Leonardi (1987).
These pictures, taken with a Fujifilm S8000fd, 8 million pixel camera, are all of footprint dorsal surfaces and were processed by MB with Agisoft Photoscan Pro (v. 0.8.4). This allowed fair 3D models to be generated, although the lack of angled photos has led to several incomplete-to-voided regions. Resulting models are nevertheless good enough to allow us to generate colour-coded maps of footprint depths (Fig. 2) as well as contour lines using ParaView (v. 3.14). Measurements of tracks were then made directly using meshes generated in Polyworks (v. 10.0) following the procedures applied and tested in Belvedere et al. (2010).
Track description and interpretation
The ichnological interpretations presented here are based on incomplete 3D models and thus must be considered preliminary.
DD_01. This track (Fig. 2, A-B) is longer (16 cm) than wide (11 cm), roughly bell-shaped and with its anterior part larger than the posterior. Three possible digits are present, short and rounded with no claw impressions. The deepest part is located in the middle of the track, but this preservation could be due to recent erosion. The three blunt toes, together with the general shape of the track, allow us to identify this print as a possible Deltapodus (Romano and Whyte, 1995).
DD_02. This tridactyl track is roughly as long (13 cm) as wide (11 cm), with short rounded digits and interdigital angles that are symmetrical. Its short blunt digits and symmetrical interdigital angles suggest an ornithopod trackmaker, but preservation prevents a more detailed interpretation.
DD_03. This footprint is slightly longer (18 cm) than wide (17 cm), is asymmetrical (II^III < III^IV) and with digit III probably the longest. All digits are slender with tapering terminations; no pads or claw mark impressions are preserved. These morphological features allow us to identify this footprint (with a reasonable degree of certainty) as a theropod track.
DD_04. This trace (Fig. 2, C-D) is one of the most ambiguous recovered. At first glance, from the photo (Fig. 2 E), it might be considered to be from a sauropod manus, whereas based on the 3D model (Fig. 2 F) it is possible to see three clear digits, with probable digit I and metatarsal impressions. As in DD_01, the maximum depth of this track is around the middle of the print and is thus probably a result of recent erosion. This print is longer (17 cm) than it is wide (13 cm) and is slightly asymmetrical (II^III < III^IV). No further information is available, but it is identified here as a probable theropod footprint.
Tracks from DD_05 to DD_08 present no clear pad impresssions or claw marks and all have similar morphological charactersitics: slender digits with tapering terminations, asymmetric interdigital angles (II^III < III^IV), athough all are slightly different sizes (see Table 1). All these preserved features allow us to identify them as theropod tracks.
DD_09. The preservation of this footprint is quite poor and morphological characteristics are barely identifiable. However, two digits are visible while the third is not well preserved. The footprint is slightly longer (22 cm) than wide (19 cm), and almost symmetrical; the digits are blunt and short probably because of erosion.
DD_10. As is the case for DD_09, the preservation of this footprint is very poor but it is possible to clearly recognise two rounded digits while a third is only partially preserved (Fig. 2, G-H). This footprint is longer (23 cm) than wide (21 cm) and has slightly asymmetrical intergitial angles. Although a clear identification for DD_09 and DD_10 is not possible, symmetry in the interdigital angles and the short digits allows to suppose an probable ornithopod trackmaker.
Although very preliminary and based on few prints, this study increases our baseline knowledge of Isle of Wight dinosaurs and highlights the potential of ichnological analyses which will provide more detailed palaeobiological data in the future.
References
BELVEDERE, M., MIETTO, P. and ISHIGAKI, S. 2010. A Late Jurassic diverse ichnocoenosis from the siliciclastic Iouaridène Formation (Central High Atlas, Morocco). Geological Quarterly, 54: 367–380.
FALKINGHAM, P. L., BATES, K. T., MARGETTS L., and MANNING, P. L. 2011. The 'Goldilocks' effect: preservation bias in vertebrate track assemblages. Journal of the Royal Society: Interface, 8: 1142-1154.
GOLDRING, R., POLLARD, J. E. and RADLEY, J. D. 2005. Trace fossils and pseudofossils from the Wealden strata (non-marine Lower Cretaceous) of southern England. Cretaceous Research, 26: 665-685.
LEONARDI, G. 1987. Glossary and manual of tetrapod footprint palaeoichnology. Publicação do Departemento Nacional da Produção Mineral Brasil. Brasíli, 117 p.
MARTILL, D. M. and NAISH, D. 2001. Dinosaurs of the Isle of Wight. Palaeontological Association, London, 433 p.
RADLEY, J. D., BARKER, M. J. and HARDING, I. C. 1998. Palaeoenvironment and taphonomy of dinosaur tracks in the Vectis Formation (Lower Cretaceous) of the Wessex Sub-basin, southern England. Cretaceous Research, 19: 471-487.
WHYTE, M. A. and ROMANO, M. 1994. Probable sauropod footprints from the Middle Jurassic of Yorkshire. Gaia, 10: 15-26.
represent a unique ichnological resource. However, with a few notable exceptions, these ichnites remain largely
unstudied and documentation has been sporadic and often concentrated on a few particular sites. Thus, their
context within the Lower Cretaceous is poorly understood. The vertebrate ichnological record of the Wessex
Sub-basin is currently being re-assessed. We review the main sites containing dinosaur footprints on the Isle of
Wight. We also look at previously-known sites, and present new research using techniques such as photogrammetry
to accurately record, preserve, and distribute ichnological data, especially data recorded in the dynamic foreshore
and cliff environments, where many trace fossils are frequently lost as a result of human activity, weathering,
erosion, and changing marine dynamics. Although the ichnoassemblages of the island’s Wealden facies are
dominated by ornithopod tracks including Caririchnium and Amblydactylus, we also report the first occurrence of
the ankylosaurian track Tetrapodosaurus in both the Wessex and Vectis Formations, alongside the previously
reported stegosaurian Deltapodus, as well as the occurrence of tracks left by saurichian tracemakers. © 2014 The
Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 737–757.
Slabs bearing Rhynchosauroides prints that were purchased by the Natural History Museum in 1848 and 1858 were erroneously listed as coming from ‘Staunton’ but were actually found at Stanton, close to Burton on Trent and about 2km from the Ashby Road finds.
The history of these finds is detailed together with a review of the geology and significance of this ichnoassemblage. The Ashby Road tracks are assigned to Chirotherium cf. barthii and the Stanton tracks to Rhynchosauroides rectipes and Rotodactylus isp. The Chirotherium tracks have an unusually large digit II and manus.
Photogrammetric methods have been used to enhance details of the Chirotherium specimens.