Sunday, January 29, 2012

Sauropods of the British Isles I

 Fig 1.- Reconstruction of Cetiosaurus oxoniensis.

Sauropods, the long-necked, long-tailed giant herbivorous dinosaurs, are better known in popular imagination by their North American representatives, Diplodocus and Brachiosaurus. Sauropods are divided into a number of families and groups that can be distinguished from details of their skeletal anatomy and teeth. Among the most primitive families, the Melanosaurids were only recently (Yates, 2007) recognized as early sauropods instead of being placed within more basal sauropodomorphs. Cetiosaurids are an ill-defined group of primitive sauropods built around the British Cetiosaurus and perhaps including other members such as the Chinese club-tailed Shunosaurus. The Turiasaurs form a recently erected clad (Royo-Torres et al., 2006) of gigantic sauropods so far restricted to southernwestern Europe. The Diplodocoids regroup three distinct families, the highly specialized rebbachisaurids, the relatively short-necked, tall-spined dicraeosaurids and the long and slender diplodocids. The Macronarians are characterized by their erect neck posture and comparatively large nasal opening (nostrils) on their head. They are subdivided into the camarasaurids (primitive macronarians), brachiosaurids and titanosaurs, the last two families including the largest and heaviest creatures that ever walked the earth.

Numerous remains of sauropods were found in the British Isles, but the vast majority of the named genera and species are based on very scant material with no unique characteristics making them nomina dubia (dubious names). However, they can generally be diagnosed at higher group levels, showing that the British Isles were once home to a diverse fauna of sauropods that include the earliest members of such groups as the Diplodocoidea and Rebbachisauridae. Let’s meet them in stratigraphical chronological order (please note that the list of fossils mentioned is in no way exhaustive)...

We already met in a previous post, Camelotia borealis from the Westbury Formation of Late Triassic Rhaetian age, which was possibly an early sauropod, unless it is a large representative of something more basal.

Sauropods from the Middle Jurassic

The first definite British sauropod remain comes from the Middle Jurassic Aalenian stage (~175 MYA). It consists of a partial left pubis and ischium (BMNH R9472) of the Northampton Sands Formation, from Harleston, Northamptonshire (Reid, 1984). This unnamed taxon was possibly a brachiosaurid or a titanosaur making it either way the earliest recorded macronarian in the world.

Fig 2.- Britain has some remains belonging to the earliest known macronarian.

Next come large collection of bones from the Forest Marble Formation of Bathonian age (~165 MYA).  The most famous fossil of this formation is the primitive sauropod Cetiosaurus (“whale lizard”). Cetiosaurus is one of the earliest dinosaurs to receive a name and, as it happened to many genera described in the early days of paleontology, it became a so-called wastebasket taxon, with up to 13 species described in the British Isles alone, ranging temporally from the Middle Jurassic to the Early Cretaceous. In a general revision of the genus, Upchurch and Martin (2003) finally recognized the only Cetiosaurus oxoniensis Phillips, 1871 from the Forest Marble as a valid species.  Cetiosaurus is known from various postcranial elements coming from different places in Oxfordshire (OUM J13605-13613, 13615-13616, 13619-13688, 13899), Northamptonshire and Gloucestershire. A partial skeleton from the slightly older Bajocian (~ 170 MYA) Rutland Formation of Rutland (LCM G468.1968) is also being assigned to C. oxoniensis, as well as a partial braincase (OUM J13596) and a tooth (OUM J13597) found at the same location than the Oxfordshire Blechington specimen. This large, perhaps 20 meters long sauropod exhibits a number of primitive features in the structure of their vertebrae.  Due to the fragmentary nature of the remains, many aspects of this animal, such as the skull, are almost totally unknown, despite it being the best-known sauropod of Great Britain.

Cetiosaurus medius Owen, 1842 known from 11 caudal centra (OUM J13693–13703) and other various bits found in Oxfordshire, Gloucestershire, Buckinghamshire, is non-diagnostic. Since C. medius is generally considered as the type species of Cetiosaurus, its invalidation would render the naming of C. oxoniensis problematic. A petition has therefore been filed to ICZN to make C. oxoniensis the new type species for the genus. Cardiodon rugulosus described by Owen in 1844, out of a single, now lost, tooth unearthed near Bradford-on-Avon, Wiltshire, may be the same animal than Cetiosaurus, but it was also been proposed to be a Turiasaur.

Two other distinct taxa are known from the Forest Marble Formation: one is ‘Cetiosaurus’ glymptonensis  Phillips, 1871 (= Cetiosauriscus glymptonensis (Phillips, 1871) McIntosh, 1990) described from a series of 9 caudal vertebrae (OUM J13750-13758) found in Glympton, Oxfordshire. It was possibly a diplodocoid, making it the earliest known member of this group in the world. However, due to the lack of unique characters, C. glymptonensis is generally considered to be a nomen dubium (Barrett et al., 2003). The as dubious Bothriospondylus robustus  Owen, 1875 = Marmarospondylus robustus) from Bradford-on-Avon, Wiltshire, is known from a single dorsal vertebra (BMNH R22428) and might be a macronarian.

Another possible macronarian has been described from the similar age Kilmaluag Formation (late Bathonian) of Strathaird, Isle of Skye, Western Scotland: it is a tooth (NMS G 2004.31.1), one of the very rare dinosaurian remains found in Scotland. This fossil is distinctly different from both Cetiosaurus and Cardiodon (Barrett, 2006).

From the Lower Callovian age (~163 MYA) Kellaways formation, comes ‘Ornithopsis’ leedsi Hulke, 1887, known from vertebrae, ribs and pelvic fragments (BMNH R1984-1988), found near Peterborough, Cambridgeshire. This was probably a Brachiosaurid. The name Ornithopsis originally refers to the undeterminate O. hulkei from the Early Cretaceous (see part II), which would mean that O. leedsi probably requires a new generic name.

Fig 3.- other remains from britain are from the earliest known diplodocoid.

In the overlying Oxford Clay Formation (Middle Callovian – Early Oxfordian age, ~161 MYA), other materials from Peterborough, including a series of vertebrae (BMNH R.3078) were confusingly also referred to ‘Ornithopsis’ leedsi by Woodward in 1905. But Charig concluded in 1980 that the bones belong to a quite different animal, a diplodocid, and give them the name ‘Cetiosauriscus’ stewarti.

Sauropods from the Late Jurassic

From the Kimmeridge Clay Formation of Kimmeridgian age (~153 MYA), comes Duriatitan humerocristatus (Lydekker, 1888) (Initially named 'Cetiosaurus' humerocristatus) based on a gracile left humerous (BMNH R44635) from Weymouth, Dorset (Hulke, 1874). It was determined to belong to a Titanosauriform (Barrett et al., 2010). The dubious ‘Ornithopsis’ manseli  (Lydekker, 1888) (= ‘Ischysaurus’ manseli ), based on a partial humerus ((BMNH 41626), also from Dorset, may belong to the same animal. The same can be said of Bothriospondylus suffosus Owen, 1875 from Wiltshire, known from dorsal and sacral vertebrae (BMNH R44592-5: 4).

Some non-diagnostic vertebrae, limb elements and dermal scutes found near Stretham, Cambridgeshire (BMNH 32498-99) were described as Gigantosaurus megalonyx Seeley, 1869 and belong to a sauropod of some sort. Also from the Kimmeridgian, ‘Cetiosaurus’ longus Owen, 1842 based on a single dorsal and caudal centra (OUM J13617) from the Portland Stone Formation at Garsington, Oxfordshire, is an indeterminate sauropod.

Original artworks on Paleoexhibit are copyrighted to Nobu Tamura. Do not use without permission (Email: nobu dot tamura at yahoo dot com)


P. M. Barrett. 2006. A sauropod dinosaur tooth from the Middle Jurassic of Skye, Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences 97:25-29

P. M. Barrett, R. B. J. Benson, and P. Upchurch. 2010. Dinosaurs of Dorset: Part II, the sauropod dinosaurs (Saurischia, Sauropoda) with additional comments of the theropods. Proceedings of the Dorset Natural History and Archaeological Society 131:113-126

A. J. Charig. 1980. A diplodocid sauropod from the Lower Cretaceous of England. In L. L. Jacobs (ed.), Aspects of Vertebrate History: Essays in Honor of Edwin Harris Colbert. Museum of Northern Arizona Press, Flagstaff 231-244

J. W. Hulke. 1874. Note on a very large saurian limb-bone adapted for progression upon land, from the Kimmeridge Clay of Weymouth, Dorset. Quarterly Journal of the Geological Society of London 30:16-17

D. Naish and D. M. Martill. 2007. Dinosaurs of Great Britain and the role of the Geological Society of London in their discovery: basal Dinosauria and Saurischia. Journal of the Geological Society, London 164:493-510

R. Owen. 1841. Description of a portion of the skeleton of the Cetiosaurus, a gigantic extinct saurian reptile occurring in the Oolitic formations of different portions of England. Proceedings of the Geological Society of London 3, part 2(80):457-462

R. Owen. 1875. Monographs on the fossil Reptilia of the Mesozoic formations. Part II. (Genera Bothriospondylus, Cetiosaurus, Omosaurus). The Palaeontographical Society, London 1875:15-93

M. D. Jones. 1970. Cetiosaurus oxoniensis, Phillips J. A middle Jurassic sauropod from Rutland, England. Leicester Literary and Philosophical Society 64:144-150

J. Phillips. 1871. Geology of Oxford and the Valley of the Thames. Clarendon Press, Oxford 1-523.

P. M. Upchurch and J. Martin. 2003. The anatomy and taxonomy of Cetiosaurus (Saurischia, Sauropoda) from the Middle Jurassic of England. Journal of Vertebrate Paleontology 23(1):208-231.

Spinops: my very own personal paleoart portfolio

Once upon a while, scientists came with really catchy dinosaur names. Examples of cool generic nomina include Dracorex (the “dragon king”), Raptorex (the “king thief”), Cryptoraptor (the “hidden thief”), Brontosaurus (the “thunder lizard”) and Diabloceratops (the “devil horn face”). Shame that some of those critters turn out to be invalid and too bad scientific names cannot be recycled! Others are just plain awful. For (at least) English speakers, there are real tongue twisters such as Bruhatkayosaurus (fortunately this one might just be a hoax [great post from Matt Martyniuk]), Futalognkosaurus (do I even get the spelling right?), Krzyzanowskisaurus, Naashoibitosaurus

 Among the recently allocated names, Spinops is one of the best I came across: it is short, easy to remember and combines those of two of the most iconic dinosaurs, Spinosaurus and Triceratops. Good reasons to use it for my new paleoart portfolio website, before somebody else get the same idea… 

I’ve just started, and so far it has only some 140 images in it as I have to go through all my folders and hard drives to check what I've done since 2007. The nice thing about this online portfolio is that it is wholly searchable (type for instance “plesiosaur” if you want to see these only), and illustrations can be arranged by group or production date. Have a look

Sunday, January 8, 2012

Late Triassic Dinosaurs of the British Isles

Fig 1.- Thecodontosaurus antiquus.

The British Late Triassic land vertebrate fauna is essentially known from disarticulated bones found in various Mesozoic fissure fills of underlying Lower Carboniferous limestone in England and Wales. The fauna include the very first British dinosaurs of Rhaetian age (~ 200 MYA), living alongside a variety of reptiles including sphenodontians, running crocs of the sphenosuchian group (such as Terrestrisuchus gracilis), trilophosaurs (such as Variodens inopinatus), and gliding lizards such as Kuhneosaurus. Dinosaurs were not the dominant group that will rule the land during the Jurassic and Cretaceous periods, constituting only about 10% of the vertebrate fauna found in those fissure fills. One archosaurian form, named Agnostiphys cromhallensis from the Cromhall Quarry in Avon, has clearly some dinosaurian characteristics. It was described in 2002 by N.C. Fraser and co-workers based on a left ilium, left maxilla, a right humerus, a pair of astragalus and an isolated tooth. The validity of the taxon is disputed as the different parts may come from different animals (thus making the original description a chimera) and the remains are too scant to decide if it was an archosaur closely related to dinosaurs or a true primitive dinosaur, possibly a herrerasaur.

Sauropodomorphs from Rhaetian fissure fills: Thecodontosaurus, Asylosaurus, Pantydraco

The other dinosaurian remains of the Rhaetian fissure fillings all belong to basal sauropodomorphs, the group of saurischian dinosaurs which will eventually lead to the Jurassic and Cretaceous long-necked herbivorous giants called Sauropods to which the North American Brachiosaurus, Diplodocus and Apatosaurus are the most popular members. From a locality known as Durdham Down, Clifton, near Bristol in England, hundreds of bones have been excavated in the 1830s and originally described by Riley and Stutchbury as three separate taxa: Thecodontosaurus antiquus based on a right dentary with 21 teeth, Paleosaurus cylindricon (Now Paleosauriscus cylindicon) and P. platyodon (now Rileyasuchus platyodon), the latter two, each based on a single tooth. The other bones were subsequently distributed by Owen (1842), Huxley (1870) and Marsh (1892) among the three taxa. Huxley (1870) was the first to recognize the dinosaurian nature of the remains. The different disarticulated bits had subsequently quite diverging and complicated systematic histories, some being referred to a phytosaur (i.e. Rileya), others to theropods and ornithosuchians. Sadly, a portion of the materials, including the holotype dentary of Thecodontosaurus, was destroyed during the WWII bombing of Bristol. Recent efforts try to put order in the systematic mess accumulated over more than a century, but opinions went from attributing all the Durdham Down dinosaurian bones to the single species of basal sauropodomorph, Thecodontosaurus antiquus (Benton et al., 2000) with different morphotypes representing sexual dimorphism, to reserving the generic name to the original jaw and its neotype only (Galton, 2005). In his last magisterial review, Pete Galton (2007) examined all the surviving materials of Durdham Down (including the mislabeled bones which were for a while thought to come from Australia, leading Seeley to described them in 1861 as a new species, Agrosaurus macgillivray, which would have been the earliest known dino from down under) and illustrations made of materials lost during the war. He concluded that the Durdham Down collection is a mixture originating from a handful of species: Thecodontosaurus antiquus, to which the jaw and gracile bones were attributed, a new erected taxon, Asylosaurus yalensis for the only significant articulated skeletal part (an almost complete forearm and associated dorsal vertebrae and ribs), and a few number of unnamed basal sauropodomorphs, including a possible anchisaur. New materials of Thecodontosaurus have been discovered in fissure fill at Tytherington Quarry, Avon, in 1975 are are being prepared and awaiting formal description. Compared to the later huge sauropods, Thecodontosaurus was a rather small dinosaur measuring no longer than 2.5 meters in length that was probably bipedal. His leaf shaped teeth indicated that it was a herbivore.

Fig 2.- Pantydraco caducus.

From the more or less contemporary fissures fill of Panty-ffynnon Quarry in South-Western Wales, came several partial skeletons including an almost complete skull and associated partial skeleton of the unfortunately named Pantydraco caducus. The remains are from a juvenile basal sauropodomorph. Like Thecodontosaurus, Pantydraco was a bipedal herbivore, measuring probably no more than 2 meters in length.

Fig 3.- Camelotia borealis.

The large Late Triassic sauropodomorph, Camelotia

All the sauropodomorphs from the rhaetian fissure fills were rather small in size and gracile in appearance, but a larger animal announcing the heavy sauropods from the Jurassic, existed at that time, as proven by a partial disarticulated skeleton found in sedimentary beds at the base of the Westbury formation at Wedmore Hill, Somerset. The animal was named Camelotia borealis, after the legendary castle of King Arthur.  Remains of Camelotia are so fragmentary that it is hard to derive its affinities but it might have been related to the quadrupedal Melanosaurus, unless it was a very primitive sauropod. Camelotia is estimated to have measured about 10 meters in length.

Original artworks on Paleoexhibit are copyrighted to Nobu Tamura. Do not use without permission (Email: nobu dot tamura at yahoo dot com)


Benton M.J. , Juul, L., Storrs, G.W. & Galton, P. M. 2000. Anatomy and systematics of the prosauropod dinosaur Thecodontosaurus antiquus from the Upper Triassic of Southwest England. Journal of Vertebrate Paleontology 20: 77–108.

Fraser, N. C., K. Padian, G. M. Walkden, & A.L.M. Davis , 2002. Basal dinosauriform remains from Britain and the diagnosis of the Dinosauria. Palaeontology , 45 (1): 79-95.

Galton. P. M. 2005. Basal sauropodomorph dinosaur taxa Thecodontosaurus Riley & Stutchbury, 1836, T. antiquus Morris, 1843 and T. caducus Yates, 2003: their status re: humeral morphs from the 1834 fissure fill (Upper Triassic) in Clifton, Bristol, UK. Journal of Vertebrate Paleontology 25(3, suppl.):61A

Galton, P. M. 2007. Notes on the remains of archosaurian reptiles, mostly basal sauropodomorph dinosaurs, from the 1834 fissure fill (Rhaetian, Upper Triassic) at Clifton in Bristol, southwest England. Revue de Paléobiologie 26(2):505-591.

Galton, P. M., Yates, A. M.  and Kermack, D. M. 2007. Pantydraco n. gen. for Thecodontosaurus caducus Yates, 2003, a basal sauropodomorph dinosaur from the Upper Triassic or Lower Jurassic of South Wales, UK. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen 243(1):119-125.

Naish, D. and Martill., D. M. 2007. Dinosaurs of Great Britain and the role of the Geological Society of London in their discovery: basal Dinosauria and Saurischia. Journal of the Geological Society, London 164:493-510

Yates. A.M. 2003. A new species of the primitive dinosaur Thecodontosaurus (Saurischia: Sauropodomorpha) and its implications for the systematics of early dinosaurs. Journal of Systematic Palaeontology 1(1):1-42.

Wednesday, January 4, 2012

R.I.P. Dan Varner (April 19, 1949 - January 1, 2012)

Mosasaurus by Dan Varner.

I did not have the privilege to know Dan Varner and did not know until very recently, shame on me, that he was the man behind the beautiful paintings illustrating the “Oceans of Kansas” website. I sadly learned that he passed away on January 1st, 2012 after a prolonged battle with illness;  a tremendous loss for the entire paleoart community…

From all the amazing Mesozoic marine life depictions he created during his too short a career, this one is a personal favorite. Mosasaurs were after all closely related to the modern monitor lizards, so it makes perfect sense to give them a similar tongue! The underwater light effect is eye-catching and the three transfixed ammonites watching the marine lizard swimming by gives to the entire scene a unique sense of cephalopodian apprehension... simply beautiful!

It’s hardly my place, I think, for me, an amateur nobody, to give a fitting eulogy to such a great artist so I am simply directing you to the ‘in memoriam’ sections I came across on the web, starting with the “Oceans of Kansas” website, followed by tributes from paleo-illustrators Jaime Headden (check his Globidens), Matt van Roojien, David Maas and from the Art Evolved Crew.

Monday, January 2, 2012

Ankylosaurs of the British Isles

Fig 1.- Hyleosaurus armatus.

The Ankylosaurs form a group of heavily armored ornithischian dinosaurs best known by its North American cretaceous representatives, Ankylosaurus and Euoplocephalus. Ankylosaurs and Stegosaurs together form the Thyreophorans characterized by a body covered with an armor consisting of scutes, spikes and plates, that are highly derived osteoderms (ossified scales commonly found in various groups of vertebrates such as the crocodilians).

The Ankylosaurs are divided into two or three families. The Nodosaurids have a narrow skull, a club-less tail and large spikes while the Ankylosaurids have a distinct bony club at the end of their tails and a wider body. In addition, some authors detach some Nodosaurids, into a third family, the more lightly built Polacanthids.

Scelidosaurus harrisonii from the Early Jurassic of Dorset, is an early thyreophoran close to the ancestral stock of both stegosaurs and ankylosaurs. There is however a large gap in the fossil record between the first definite ankylosaur in the United Kingdom and Scelidosaurus. Jurassic ankylosaur remains are so fragmentary that not much definite can be said about them.

In the Middle Jurassic (Bajocian, 170 MYA), an incomplete radius and ulna (forearm bones) from the Isle of Skye in Scotland, described by Clark in 2001, possibly belongs to an ankylosaur, unless it is a stegosaur.

A bit younger (Middle Jurassic, Callovian, 163 MYA), Sarcolestes leedsi is known from an incomplete lower jaw from the Oxford Clay Formation in Cambridgeshire. Three osteoderms recovered from the same formation have been attributed to it (Galton, 1994). It was originally thought to be a theropod (thus its name meaning “flesh robber”), before being classified as a stegosaur, then an ankylosaur of some sort.

From the Late Jurassic period (Oxfordian, 160 MYA), a right femur found in the Ampthill Clay Formation of Cambridgeshire was named Cryptosaurus eumerus and first attributed to an ornithopod, until Peter Galton placed it among the ankylosaurs (1983). A maxilla of the same age named Priodontognathus phillipsi was found in Yorkshire. This also was first attributed to an ornithopod before Galton classified it as a nodosaurid ankylosaur (1980).

Better ankylosaur material appears in the Early Cretaceous with Hylaeosaurus and Polacanthus. Hylaeosaurus armatus is one of the original three animals (the others being Iguanodon and Megalosaurus) used by Sir Richard Owen to define the then new group he called Dinosauria in 1842. This 6 meter long polacanthid nodosaur is known from the Turnbridge Wells Sand Formation (Grinstead Clay member) of Valanginian age (~138 MYA) and its remains have been discovered in West Sussex. The holotype found in the Tilgate Forest area by Gideon Mantell in 1832 consists of the anterior portion of an articulated skeleton including a small portion of the skull. A second specimen from Bolney was partially destroyed by workers before Mantell could salvage a few bits including a left scapula, a fragment of the right scapula and a left tibia. A third specimen found by Mantell in 1827 from the Tilgate Forest quarry consists of an incomplete caudal series with armor (originally named H. oweni).  From Mantell’s Bolney material combined with remains found in the Isle of Wight, Nopsca erected the new genus and species Polacanthoides ponderosus in 1928. Today, the Bolney material is attributed to Hylaeosaurus armatus while the Isle of Wight material is considered to belong to Polacanthus foxii, making Polacanthoides an invalid name. Hylaeosaurus is still a quite obscure animal despite being one of the earliest described dinosaurs. It was probably closely related to Polacanthus.

Fig 2.- Polacanthus foxii.

Polacanthus foxii, which was for some times being considered to be the same animal as Hylaeosaurus, is nowadays generally thought to be distinct. Stratigraphically, it is slightly younger, appearing only in the Wessex and Vectis Formations of the Isle of Wight of Upper Barremian age (~ 125 MYA). The generic name appears first in a anonymous field note from 1865 attributing the paternity of the name to Richard Owen. The holotype collected by the reverend William Fox consists of the rear end of the animal. A second specimen described by W. T. Blows in 1979 consists of neck vertebrae and anterior armor. A third specimen is currently in private ownership. A portion of a pelvis and some dermal armor, originally named Polacanthus becklesi by Hennig in 1924 is now considered to belong to P. foxii. Many other various bits attributed to P. foxii have been found including the now lost Isle of Wight parts used to define Polacanthoides ponderosus described above and the single spine named Vectensia by Delair, 1982.  Polacanthus foxii was a 4-5 meter long nodosaur, serving as the type to the polacanthid family.

Blows has erected a second species of Polacanthus, P. rudgwickensis, in 1996 out of a partial skeleton from the mainland found near Rudgwick, Sussex. This species appears to be slightly larger and more robust than P. foxii but its validity has been disputed.

Fig 3.- Anoplosaurus curtonotus

From the mainland Upper Greensand Formation of Albian age (~110 MYA), a number of fragments were attributed to ankylosaurs and named into several genera including Anoplosaurus, Acanthopholis, Eucercosaurus, Syngonosaurus and Macrurosaurus and a plethora of species. All of them, save perhaps Anoplosaurus curtonotus are dubious in the sense that from such fragmentary remains there are no unique characters to define each of the species.  Anoplosaurus curtonotus has been described from various fragments from a juvenile individual and probably belong to a nodosaurid of some sort. The second species, A. major is probably chimeric. The genus Acanthopholis was often illustrated in dinosaur books but all the 7-9 species described, including the type A. horrida, were determined to be dubious by a review by Pereda-Superbiola and Barrett (1999).

This concludes our tour of the British Isles Ornithischians. Now to the Saurischians.

Original artworks on Paleoexhibit are copyrighted to Nobu Tamura. Do not use without permission (Email: nobu dot tamura at yahoo dot com).


Blows, W. T.  1982. A preliminary account of a new specimen of Polacanthus foxi (Ankylosauria, Reptilia) from the Wealden of the Isle of Wight. Proceedings of the Isle of Wight Natural History and Archaeological Society 1980 pt. 5(7):303-306.

Clark, N.D.L. 2001. A thyreophoran dinosaur from the early Bajocian (Middle Jurassic) of the Isle of Skye, Scotland. Scottish Journal of Geology, 37, 19–26.

Fox. W. 1866. On a new Wealden saurian named Polacanthus. Report of the British Association for the Advancement of Science, Birmingham 1865:56.

Fox. W.1866. Another new Wealden reptile. Geological Magazine 3:383.

Galton, P.M. 1980. Priodontognathus phillipsii (Seeley), an ankylosaurian dinosaur from the Upper Jurassic (or possibly Lower Cretaceous) of England. Neues Jahrbuch für Geologie und Paläontologie Monatshefte 1980(8):477-489.

Galton, P.M. 1983. Armored dinosaurs (Ornithischia: Ankylosauria) from the Middle and Upper Jurassic of Europe, Palaeontographica Abteilung A 182(1-3): 1-25.

Galton, P. M.  1994. Dermal scutes of Sarcolestes, an ankylosaurian dinosaur from the Middle Jurassic of England. Neues Jahrbuch für Geologie und Paläontologie Monatshefte 1994(12):726-732

Naish, D.; and Martill, D. M. 2008. Dinosaurs of Great Britain and the role of the Geological Society of London in their discovery: Ornithischia. Journal of the Geological Society, London 165 (3): 613–623.

Pereda-Suberbiola, J. 1993. Hylaeosaurus, Polacanthus, and the systematics and stratigraphy of Wealden armoured dinosaurs. Geological Magazine, 130, 767-781.

Pereda-Suberbiola, J. 1994. Polacanthus (Ornithischia, Ankylosauria), a transatlantic armoured dinosaur from the Early Cretaceous of Europe and North America. Palaeontographica Abteilung A 232(4-6):133-159.

Pereda-Suberbiola, J. & Barrett. P.M., 1999. A systematic review of ankylosaurian dinosaur remains from the Albian-Cenomanian of England, Special Papers in Palaeontology, 60: 177-208.