An artist’s impression of Comptonatus chasei.
Image credit: John Sibbick
The fossil remains of a dinosaur, discovered in the cliffs of Compton Bay, Isle of Wight, England, have been shown to be a species new to science. The fossils were discovered in 2013 by the late fossil collector Nick Chase, who sadly died of cancer before his finds could be fully analysed. Nick Chase had a record of fossil discovery, including the most complete Iguanodon skull ever found, yet never had a new species named after him
That has now been rectified by retired GP and PhD student at the School of the Environment, Geography and Geosciences, University of Portsmouth, UK, Jeremy Lockwood, who helped with the dinosaur's excavation and has spent years analysing it to determine that it is a new species which he has named Comptonatus chasei. It has proven to be the most intact dinosaur ever discovered in Britain.
Together with David Martell, also of the School of the Environment, Geography and Geosciences, University of Portsmouth and Susannah Maidment of the Fossil Reptiles, Amphibians and Birds Section, Natural History Museum, London, UK, Dr Lockwood has published his findings, open access, in the Journal of Systematic Palaeontology. Their work is also explained in a University of Portsmouth press release:
What can you tell me about the cliffs at Compton Bay, Isle of Wight, England, and how geologists know how old they are? The cliffs at Compton Bay, located on the Isle of Wight in England, are a geological treasure trove, providing valuable insights into the Earth's history. These cliffs are composed primarily of sedimentary rocks that date back to the Early Cretaceous period, which means they are around 125 million years old.
Geological Features
Dating the Cliffs
- Composition:
- The cliffs primarily consist of layers of sandstone, clay, and limestone. These sedimentary rocks were formed in a variety of ancient environments, including river deltas, shallow seas, and coastal swamps.
- Stratigraphy:
- The cliffs at Compton Bay display a well-preserved stratigraphic sequence. The different rock layers are stacked in a way that records the sequence of deposition over millions of years. This stratigraphy is key to understanding the geological history of the area.
- Fossils:
- The cliffs are renowned for their fossil content, particularly dinosaur fossils. Footprints of dinosaurs such as Iguanodon and footprints from various species can be found in the exposed rock layers. Additionally, fossils of plants and marine creatures provide a broader picture of the ecosystem during the Cretaceous period.
Geologists determine the age of the cliffs at Compton Bay through several methods:
- Biostratigraphy:
- This method involves dating the rock layers based on the fossils they contain. Certain fossils, known as index fossils, are indicative of specific geological periods. By identifying these fossils within the cliffs, geologists can correlate the rock layers with known periods in Earth's history.
- Radiometric Dating:
- While sedimentary rocks themselves are difficult to date radiometrically, geologists can date volcanic ash layers or igneous intrusions within the sedimentary sequence. These dates can then be used to constrain the ages of the surrounding sedimentary layers.
- Stratigraphic Correlation:
- Geologists compare the rock sequences at Compton Bay with those in other locations, both regionally and globally. By correlating these sequences, they can refine the age estimates of the rocks.
- Paleomagnetic Studies:
- This technique involves studying the magnetic minerals within the rock layers. These minerals can record the Earth's magnetic field at the time the rocks were formed. By comparing these magnetic signatures with the global geomagnetic polarity time scale, geologists can estimate the age of the rocks.
Geological Significance
The cliffs at Compton Bay are not only a site of natural beauty but also a crucial location for understanding the Early Cretaceous period. They provide insights into the paleoenvironment, paleoclimate, and the types of organisms that inhabited the Earth at that time. The study of these cliffs continues to yield important scientific information, contributing to our understanding of Earth's geological past.
Research reveals the most complete dinosaur discovered in the UK in a Century
The specimen is around 125 million years old and was found in the cliffs of Compton Bay on the Isle of Wight
The most complete dinosaur discovered in this country in the last 100 years, with a pubic hip bone the size of a ‘dinner plate’, has been described in a new paper published today.
The specimen, which is around 125 million years old, was found in the cliffs of Compton Bay on the Isle of Wight in 2013 by fossil collector Nick Chase, before he tragically died of cancer.
Jeremy Lockwood, a retired GP and University of Portsmouth PhD student, helped with the dinosaur’s excavation and has spent years analysing the 149 different bones that make up the skeleton.
Jeremy determined that the skeleton represented a new genus and species, which he named Comptonatus chasei in tribute to Nick.
Nick had a phenomenal nose for finding dinosaur bones - he really was a modern-day Mary Anning. He collected fossils daily in all weathers and donated them to museums. I was hoping we’d spend our dotage collecting together as we were of similar ages, but sadly that wasn’t to be the case.
Despite his many wonderful discoveries over the years, including the most complete Iguanodon skull ever found in Britain, this is the first dinosaur to be named after him.
Dr Jeremy A. F. Lockwood, lead author
School of the Environment, Geography and Geosciences,
University of Portsmouth, UK.
When it was first discovered, the specimen was thought to be a known dinosaur called Mantellisaurus, but Jeremy’s study revealed a lot more dinosaur diversity. Indeed, this is the second new genus to be described by Jeremy.
I’ve been able to show this dinosaur is different because of certain unique features in its skull, teeth and other parts of its body. For example its lower jaw has a straight bottom edge, whereas most iguanodontians have a jaw that curves downwards. It also has a very large pubic hip bone, which is much bigger than other similar dinosaurs. It’s like a dinner plate!
Dr Jeremy A. F. Lockwood.
Jeremy doesn’t know why the pubic hip bone, which is placed at the base of the abdomen was so big:
It was probably for muscle attachments, which might mean its mode of locomotion was a bit different, or it could have been to support the stomach contents more effectively, or even have been involved in how the animal breathed, but all of these theories are somewhat speculative.
Dr Jeremy A. F. Lockwood.
Jeremy named the dinosaur Comptonatus after Compton Bay where it was found and ‘tonatus’ is a Latin word meaning ‘thunderous’.
This animal would have been around a ton, about as big as a large male American bison. And evidence from fossil footprints found nearby shows it was likely to be a herding animal, so possibly large herds of these heavy dinosaurs may have been thundering around if spooked by predators on the floodplains over 120 million years ago.
Dr Jeremy A. F. Lockwood.
The 'dinner plate' pubic hip boneComptonatus is a fantastic dinosaur specimen: one of the most complete to be found in the UK in a century. Its recognition as a new species is due to incredibly detailed work by NHM Scientific Associate Dr Jeremy Lockwood, whose research continues to reveal that the diversity of dinosaurs in southern England in the Early Cretaceous was much greater than previously realised.
The specimen, which is younger than Brighstoneus but older than Mantellisaurus (two iguandontian dinosaurs closely related to Comptonatus) demonstrate fast rates of evolution in iguandontian dinosaurs during this time period, and could help us understand how ecosystems recovered after a putative extinction event at the end of the Jurassic Period.
Dr Susannah Maidment, senior author
Senior Researcher and palaeontologist
Natural History Museum (NHM).Despite only four new dinosaur species being described on the Isle of Wight in the whole of the 1900s, there have been eight new species named in the last five years.
The late Nick Chase, an avid fossil collector who found Comptonatus chasei in the cliffs of Compton Bay in 2013
This really is a remarkable find. It helps us understand more about the different types of dinosaurs that lived in England in the Early Cretaceous. This adds to recent research that shows that Wessex was one of the world’s most diverse ecosystems.
Dr Jeremy A. F. Lockwood.
The dinosaur has been added to the collections at the Dinosaur Isle Museum in Sandown on the Isle of Wight. The paper is published today in the Journal of Systematic Palaeontology.
Ongoing research on the museum collection continues to reveal exciting new discoveries. Most of Nick’s most important finds have remained on the Island, a lasting legacy. We can look forward to many more new types of prehistoric creatures being discovered from the Island’s cliffs and collection.
Dr Martin Munt,
Curator, Dinosaur Isle Museum, Sandown, Isle of Wight, UK.This extraordinary discovery at National Trust's Compton Bay highlights the rich natural heritage of the Isle of Wight. Finding the most complete dinosaur in the UK in a century not only showcases the island's palaeontological significance but also underscores the importance of preserving our landscapes for future generations to explore and learn from.
Nick Chase's remarkable find and Jeremy Lockwood's dedicated research are a testament to the incredible history waiting to be uncovered here. We are thrilled to be part of this ongoing journey of discovery and scientific advancement.
Mike Greenslade
General Manager for the National Trust on the Isle of Wight.
Technical details are in the abstract and introduction to the paper in the Journal of Systematic Palaeontology:
AbstractThe body of the paper contains links to references which deal with the age of the geological formation in which this fossil was found, so I'll leave creationists to trawl through it to find something to misrepresent of lie about, rather than accept that the author of Genesis wrote from a level of ignorance found today only in primitive hunter-gatherer societies, Christian and Islamic fundamentalist societies, and the American Bible belt.
A new iguanodontian dinosaur, Comptonatus chasei gen. et sp. nov., is described from the Lower Cretaceous Wessex Formation of the Isle of Wight. These strata provide an important record of a critical time in the development of iguanodontian diversity. The specimen, which is described here for the first time, was found and excavated in 2013 and represents the most complete iguanodontian skeleton discovered in the Wealden Group for a century. A new taxon is diagnosed by several autapomorphies found in the neurocranium, teeth, coracoid and other parts of the body, together with a unique suite of characters. These include a dentary with a straight ventral border, and a markedly expanded prepubic blade. These features set it apart from the sympatric Mantellisaurus atherfieldensis, Brighstoneus simmondsi and Iguanodon cf. bernissartensis, increasing the known diversity of this clade in the Barremian–early Aptian of England.
http://zoobank.org/urn:lsid:zoobank.org:pub:2F3125A5-BDEF-4835-8829-92104752A86F
Introduction
Iguanodontia was a highly successful clade of ornithischian dinosaurs, probably originating during the late Middle Jurassic, the earliest member being Callovosaurus leedsi Galton, 1980a (Lydekker, 1889) from the Oxford Clay Formation of eastern England (Ruiz-Omeñaca et al., 2007), while the youngest include the duck-billed hadrosaurids that survived to the end Maastrichtian (Horner et al., 2004). The clade also includes iconic dinosaurs such as Iguanodon bernissartensis Boulenger (in Van Beneden, 1881), Ouranosaurus nigeriensis Taquet, 1976, and Parasaurolophus walkeri Parks, 1922. Iguanodontians are historically important because teeth from an indeterminate member of the clade were the first fossils found that would become recognized as ornithischian (Mantell, 1825), and an iguanodontian sacrum recovered from the Barremian of the Isle of Wight gave Richard Owen the crucial osteological evidence he needed to ‘invent’ the Dinosauria (Owen, 1842; Torrens, 2014). Iguanodontian diversity appears to have remained low during the Late Jurassic and earliest part of the Cretaceous but increased rapidly during the Aptian and Albian (Barrett, McGowan, et al., 2009; Weishampel et al., 2004.1). The highly fossiliferous Wealden Group exposures of the Isle of Wight (Wessex and Vectis formations), which probably extend from the Late Hauterivian (Jacobs et al., 2023), through the Barremian and into the early Aptian, represent an estimated time span of at least 6 Ma (Cohen et al., 2013 updated 2023; Gale et al., 2020), and were deposited during the early stages of this radiation. They are, therefore, critical in elucidating the early development of iguanodontian diversification. The larger iguanodontians from these deposits have generally been assigned to either the very large Iguanodon bernissartensis or the medium-large and more gracile Mantellisaurus atherfieldensis (Hooley, 1925), a taxonomic practice that has effectively remained unchanged for nearly a century (Bonsor et al., 2023.2; Martill & Naish, 2001). Several other iguanodontian taxa have been erected during this time, including: Vectisaurus valdensis Hulke, 1879; Iguanodon seelyi Hulke, 1882; Sphenospondylus gracilis Lydekker, 1888; Dollodon seelyi Carpenter & Ishida, 2010; Proplanicoxa galtoni Carpenter & Ishida, 2010; and Brighstoneus simmondsi Lockwood et al., 2021. However, the validity of all bar Brighstoneus simmondsi has been challenged (Norman, 1990, 2011a, 2012, 2013.1; McDonald, 2012.1a) and most have now been subsumed into synonymy or are considered nomina dubia.
In large part, difficulties in assessing iguanodontian diversity in the Wealden Group of the Isle of Wight relate to the condition of the available material, much of which consists of isolated bones, or very incomplete partial skeletons. Despite a wealth of postcranial elements eroding from the cliffs, very little character-rich cranial material survives. This is not just a recent problem and was documented by John Whitaker Hulke (1871, p. 199), who over a hundred and fifty years ago was compelled to write, “It is remarkable that so little is known of the skulls of the Wealden Dinosauria, the more so as their other remains have been procured in some abundance in the south-east of England and the Isle of Wight during the fifty years which have elapsed since Dr Mantell's discovery of an Iguanodon's tooth in the quarry near Cuckfield”. Much of the evidence for disparity in dinosaurs is expressed in cranial material, and given its rarity on the Isle of Wight, combined with the somewhat conservative iguanodontian postcrania, a greater degree of diversity in the Wealden Group could easily have been overlooked. Recent years have also seen a steady increase in non-iguanodontian dinosaur taxa recognized from specimens collected from the Wealden Group exposures on the Isle of Wight. These represent Ornithischia with the ankylosaurian Vectipelta barretti (Pond et al., 2023.3) and the hypsilophodontid Vectidromeus insularis (Longrich et al., 2023.4) and Theropoda with the dromaeosaurid Vectiraptor greeni (Longrich et al., 2022), the spinosaurids Ceratosuchops inferodios and Riparovenator milnerae (Barker et al., 2021.1), and a possible spinosaurine (Barker et al., 2022.1).
Here we report the detailed osteology of the most complete iguanodontian skeleton found in the Wealden Group of the Wessex sub-basin since the discovery of the holotype of Mantellisaurus atherfieldensis by Reginald Hooley (1917, 1925) in 1914. The exceptional specimen described herein, which includes cranial material and most of the postcranium, was excavated from the cliffs of Compton Bay in 2013 after being discovered by the late Mr Nick Chase. Based on a unique combination of characters and several autapomorphies, we propose this as a novel taxon. Specimen IWCMS 2014.80 joins the recently described Brighstoneus simmondsi (Lockwood et al., 2021) in adding to the known iguanodontians from the Wealden Group exposures of the Isle of Wight and provides further support for an ecosystem in the Wessex Sub-basin that sustained a highly diverse and evolving iguanodontian population through the Barremian and early Aptian.
Geological setting
The term ‘Wealden’ has been used to describe several non-marine sedimentary successions from the Early Cretaceous, which span the north-west of Europe including Belgium, England, France, Germany, and the Iberian Peninsula. In southern England, these non-marine strata are represented by the Wealden Group, whose sequence can be divided into those occupying the more easterly Weald Sub-basin and those occupying the more southerly Wessex Sub-basin, the northern part of which outcrops on the Isle of Wight (Batten & Austin, 2011.1; Gale, 2019; Radley, 2006; Sweetman, 2011.2). The oldest rocks exposed on the Isle of Wight are from the Wealden Group of the Wessex Sub-basin and are found principally along the south-west coast with a smaller exposure to the east near Sandown (Fig. 1). The Wealden Group of the Isle of Wight is further divided into the older Wessex Formation and the younger Vectis Formation (Gale, 2019). The 180 m thick exposure of the Wessex Formation is largely composed of variegated overbank mudstones and siltstones, with interbedded fluvial sandstones deposited in a fluviolacustrine setting (Gale, 2019). The overlying Vectis Formation is represented by approximately 40 m of clays and shales, with occasional interbedded sandstones and shelly limestones containing the bivalve Filosina gregaria and small oysters, deposited predominantly in a shallow coastal lagoon of varying salinity (Radley & Barker, 1998, 2000; Radley et al., 1998.1). The Wessex Formation is well known for its fossil-rich plant debris beds (sensu Oldham, 1976.1), which form grey units of limited lateral extent, that were interpreted by Sweetman and Insole (2010.1, p. 409) as representing a “locally generated sheet flood, which was then transformed on the floodplain into a debris flow by the acquisition of surface material”. Despite only contributing a small volume to the overall succession (Fig. 1C), plant debris beds provide the main source of dinosaur and other vertebrate fossils on the Isle of Wight.
The strata to the south-east of Hanover Point represent the oldest units of the exposed Wealden Group (Fig. 1C), although borehole data shows that the Wealden Group on the Isle of Wight extends to a total thickness of 592 m in the subsurface (Falcon & Kent, 1960). The lack of biostratigraphically informative fossils and volcanic elements has hindered precise dating; however, palynological evidence suggests that the exposed Wessex Formation on the Isle of Wight is entirely Barremian (Allen & Wimbledon, 1991; Hughes & McDougall, 1990.1), while carbon-isotope stratigraphy has placed the ‘Pine Raft’ (an accumulation of fossilized Pseudofrenelopsis parceramosa Watson, 1977 pine trees at Hanover Point) within magnetocron M3r (Ogg, 2020.1; Robinson & Hesselbo, 2004.2), which crosses the Hauterivian–Barremian boundary (Ogg, 2020.1). This is in agreement with recent work using U-Pb geochronology on diagenetic calcite, which suggests an age of 127.3 ± 2.7 Ma (Hauterivian to earliest Barremian) for the earliest rocks exposed on the island (Jacobs et al., 2023). The overlying Vectis Formation has been shown to contain the Barremian–Aptian boundary within the Shepherds Chine Member, which forms the youngest unit of the formation (Kerth & Hailwood, 1988; Robinson & Hesselbo, 2004.2). A fault has resulted in two exposures of the Wessex and Vectis formations at Compton Bay (Radley, 1994), with IWCMS 2014.80 being discovered high in the cliff in a major plant debris bed within the Wessex Formation, north-west of the fault (Fig. 1). Dinosaur fossils are less common in the Vectis Formation, but discoveries have been made, famously including the Mantellisaurus atherfieldensis holotype (NHMUK PV R 5764), probably originating in the early Aptian (Bonsor et al., 2023.2). Correlation of the different exposures of the Wessex Formation on the Isle of Wight can be difficult, but if the sedimentation rate is broadly assumed to be uniform and continuous, then Mantellisaurus atherfieldensis, Brighstoneus simmondsi and IWCMS 2014.80 could be distanced from each other by several million years.
Figure 1. Geological setting. A, simplified geological map of the Isle of Wight. Scale bar represents 5 km. B, enlarged section of the south-west coast as outlined in A, the yellow arrow marks the location of the excavation site of IWCMS 2014.80. Scale bar represents 5 km. C, generalized stratigraphical log modified from Allen and Wimbledon (1991). Schematic lithological logs of Wealden exposure between Sudmoor and Atherfield on the Isle of Wight showing excavation sites of Brighstoneus simmondsi holotype (MIWG 6344) and the Mantellisaurus atherfieldensis holotype (NHMUK PV R 5764), adapted from Sweetman (2007.1). Wessex and Vectis formations, Compton Bay NW of fault, showing site of IWCMS 2014.80, adapted from Radley (1994). Abbreviations: mbr, member; ss, sandstone. Note that the line dividing the Wessex Formation into exposed and unexposed only applies to the Isle of Wight exposures.
Overall, the Wessex Formation represents a fluviolacustrine meander plain, which supported a rich riparian ecosystem (Austen & Batten, 2018; Batten, 2011.3; Sweetman et al., 2014.1; Sweetman, 2016). Palaeontological studies on macro and microvertebrate fossils has resulted in the Wessex Formation being shown to yield one of the world’s most taxonomically diverse, non-marine, Early Cretaceous vertebrate assemblages (Penn & Sweetman, 2022.2).
Figure 2. Comptonatus chasei gen. et sp. nov. (IWCMS 2014.80). Preliminary reconstruction of the skull. Shaded areas represent material present in the holotype.
Abbreviations: d, dentary; f, frontal; m, maxilla; n, nasal; nc, neurocranium; orb, orbit; p, parietal; pa, paroccipital process; pf, prefrontal; po, postorbital; q, quadrate, s, surangular; sq, squamosal. Scale bar represents 100 mm.
Figure 3. Comptonatus chasei gen. et sp. nov. (IWCMS 2014.80). Right maxilla in A, lateral, B, ventral, C, medial and D, dorsal views.
Abbreviations: ap, ascending process; alv, alveolar socket; dd, D-shaped depression; epr, ectopterygoid ridge; eps, ectopterygoid shelf; jp, jugal process; mc, maxillary crown; ms, medial shelf; nf, nutrient foramen; pmg, premaxillary groove; sf, special foramina. Scale bar represents 50 mm.
Figure 4. Comptonatus chasei gen. et sp. nov. (IWCMS 2014.80). Assumed right nasal fragment in A, lateral, B, dorsal, C, medial and D, ventral views.
Abbreviations: nar, naris. Scale bar represents 30 mm.
Figure 5. Comptonatus chasei gen. et sp. nov. (IWCMS 2014.80). Left quadrate in A, medial; B, lateral (yellow dashed line indicates border of paraquadratic notch); C, anterior; D, posterior; E, medial surface; F, lateral surface; G, anterior surface; H, dorsal (articular surface) and I, ventral (articular surface).
Abbreviations: ant, anterior; dc, dorsal condyle; df, dorsal flange; lat, lateral; pqn, paraquadratic notch; pw, pterygoid wing; qb, quadrate buttress; vc, ventral condyle; vf, ventral flange. Scale bar represents 50 mm.For 41 other images of fragments of Comptonatus chasei, see the publication in the Journal of Systematic PalaeontologyLockwood, J. A. F., Martill, D. M., & Maidment, S. C. R. (2024).
Comptonatus chasei, a new iguanodontian dinosaur from the Lower Cretaceous Wessex Formation of the Isle of Wight, southern England. Journal of Systematic Palaeontology, 22(1). https://doi.org/10.1080/14772019.2024.2346573
Copyright: © 2024 The authors.
Published by 2024. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
Meanwhile, open-minded, honest people who value truth above superstition and dogma can enjoy the fact of yet more evidence that a diverse population of dinosaurs once roamed what is not the Isle of Wight in southern England, 125 million years before the Bible's simple authors guessed the Universe was created out of nothing by magic.
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