Gideon Mantell’s 1851 Guide to Fossils at British Museum

This Table of Contents includes Chapters and Sections (Parts).

This Table of Contents includes Chapters, Sections (Parts), and detailed Subsections (topic headings found in the text).

The Iguanodon is repeatedly classified among the colossal Saurians of the Wealden and Oolite strata, alongside the Megalosaurus and Hylæosaurus.

Location and Significance

Fossil remains of the Iguanodon are found embedded in the Wealden deposits of the Isle of Wight and the Wealden deposits of Tilgate Forest, Sussex. The colossal size and general features of these gigantic fossil saurians, including the Iguanodon, are noted as being highly important.

Specific Specimens in the Museum (Room III)

The British Museum collection features several pieces related to the Iguanodon in Room III:

• Teeth and Bones: The contents of Case C chiefly consist of the jaws and teeth of reptiles belonging to the genus Iguanodon. These specimens were obtained from the strata of Tilgate Forest, Sussex, and were discovered and presented by the author (Gideon Algernon Mantell).
• The Maidstone Iguanodon (Table-Case 23): This is described as the most remarkable specimen of the Iguanodon hitherto obtained. It was discovered in 1834 by Mr. Bensted in a quarry of Kentish rag (a type of sandstone) near Maidstone, Kent. This specimen comprises a considerable portion of the skeleton of a young Iguanodon; the bones were separated and displaced. The specimen is noted as having afforded valuable information that enabled scientists to determine the character of this part of the skeleton of the Iguanodon.
• Limb and Associated Bones (Upper Shelf, Case C): This area contains a very fine Coracoid bone embedded in Tilgate grit, along with a portion of another Coracoid bone and eighteen inches of an unknown reptile’s intestinal structure (a Scapula). There are also portions of a very large Scapula (Peloro-saurus) associated with the Iguanodon.
• Femur and Metatarsals (Case C): A fragment of the shaft of a Femur (twenty-three inches in circumference) and two pieces of a femur, tibia, fibula, and two metatarsal bones belonging to the same young animal, but comparatively small, are present.

Anatomical and Physiological Characteristics

• Dental Structure: The Iguanodon’s teeth are described as resembling the laterally compressed, trenchant, and backward-bent teeth of the Megalosaurus, but unlike those of the Megalosaurus, the Iguanodon’s teeth are adapted for feeding on vegetables.
• Limbs and Skeleton: The thigh and leg bones, and the bones of the pelvis and vertebrae of the colossal reptiles of the Wealden (including Iguanodon) are generally enormous in size. The structure of the pelvis shows that the sacrum (the key-stone of the pelvic arch) is composed of five or six vertebrae, which are anchylosed into a solid bony arch, featuring modifications similar to those found in mammals and birds. The distortion of the strong and massive bones of the Iguanodon is noted as a truly remarkable observation from the Wealden strata.
• Vertebrae: The first caudal vertebra of the Iguanodon is always single, lacking the chevron-bone arrangement seen in Crocodilian vertebrae.
• Fossil Association: Bones (specifically femora, phalangeal bones, and parts of the teeth) of the Iguanodon are found embedded in the Wealden of Tilgate Forest, sometimes alongside remnants of the Megalosaurus.

Early Discoveries

The Maidstone Iguanodon specimen allowed for a greater understanding of the skeletal elements. The author had previously succeeded in clearing out the mass of bones, marking the relative connection of the principal pieces, and restoring the fractured parts to their original state. A detached metatarsal or metacarpal bone of the Megalosaurus is used in the exhibit to illustrate the homologous bone in the Iguanodon.

The Hylaeosaurus is categorised as one of the colossal Saurians found in the Wealden and Oolite strata, alongside the Megalosaurus and Iguanodon.

Specimens and Location (Room III)

The British Museum collection in Room III contains the first discovered specimen of the Hylaeosaurus:

First Discovered Specimen: The lower compartment in the centre of Case B houses the first discovered specimen of Hylaeosaurus.

Vertebral Column: A remarkably interesting portion of the vertebral column, showing many dermal bones of the Hylaeosaurus, is figured and described in Phil. Trans. for 1849. This specimen is noted to be present above Wall-case B, near the angle.

Dorsal Spine/Armour: A model of a nearly perfect dorsal dermal spine of the Hylaeosaurus is displayed on the right hand. This spine, which is the original specimen, is preserved in the author’s possession, having been procured from the Wealden Clay near Lewes. It measures fourteen inches long.

Sacral Vertebrae: Trays containing magnificent thigh bones and four specimens of sacral vertebrae are exhibited, highlighting their relation to the Hylaeosaurus. The sacrum (the key-stone of the pelvic arch) of Hylaeosaurus is composed of five or six vertebrae, which are anchylosed into a solid bony arch.

Anatomical Characteristics

Teeth: Like the Iguanodon, the tooth characteristics of the Hylaeosaurus are described as similar to those of the Megalosaurus—laterally compressed, trenchant, and bent backwards like a sabre with serrated edges. However, the shank of the Hylaeosaurus is conical, cylindrical, and expanded and lanceolate, with blunt margins.

Dermal Scutes: The dermal scutes of the Swanage crocodile (Goniopholis) are contrasted with those of the Hylaeosaurus, differing in having smooth and glossy interior surfaces, finely striated by decussating lines, and lacking the lateral conical projection seen in the Goniopholis scutes.

Pelvis and Vertebrae: The structure of the pelvis of the colossal reptiles of the Wealden (including Hylaeosaurus) features a sacrum composed of five or six vertebrae, anchylosed into a solid bony arch, showing modifications similar to those found in mammals and birds. The right hand vertebra is a portion of the sacrum belonging to the Megalosaurus, while the fourth specimen is part of the sacrum ascribed to the Hylaeosaurus.

The Megalosaurus is classified among the colossal Saurians of the Wealden and Oolite strata, which also include theIguanodon and Hylæosaurus.

Specific fossil materials and descriptions relating to the Megalosaurus include:

Museum Display: Two enormous coracoids, a femur, and part of a clavicle of the Megalosaurus were later discovered at Stonesfield and added to the Museum collection, where they are exhibited in Wall-case C of Room III.

Jaw and Teeth: A cast of a portion of the lower jaw with teeth of the Megalosaurus bucklandi, originating from the lower Oolite of Stonesfield, is located on the lowest shelf in Wall-Case A of Room III. The original specimen is housed at Oxford University.

Anatomy (Teeth): In terms of dental structure, the teeth of the Megalosaurus are described as laterally compressed, trenchant, and bent backwards like a sabre, possessing serrated edges. The specific mode of tooth implantation observed in the Megalosaurus is highlighted as one of the essential distinguishing modes found in fossil reptiles.

Anatomy (Vertebrae/Pelvis): The sacrum (the key-stone of the pelvic arch) of the Megalosaurus is composed of five or six vertebrae, which are anchylosed into a solid bony arch, showing modifications in the arrangement of the apophyses, similar to those found in mammals and birds.

Anatomy (Limbs): A portion of the sacrum belonging to the Megalosaurus is mentioned in relation to the generic features of the Iguanodon specimen found in the Wealden of Sussex. Additionally, bones (specifically femora, phalangeal bones, and parts of the teeth) of the Megalosaurus are found embedded in the Wealden of Tilgate Forest alongside Iguanodon remnants.

Fossil Preservation: The fossil material relating to Megalosaurus is sometimes associated with the calcified or ossified portions of bones from the Oolite of Stonesfield.

Bone Location: The position of the detached metatarsal or metacarpal bone of the Megalosaurus is detailed: it sits on the original position of Buckland’s specimen and is used to illustrate the homologous bone in the Iguanodon.

The information provided regarding Plesiosaurs concerns their geological history, characteristics, and specimens displayed in Room III of the Gallery of Organic Remains.

Classification and Importance

Plesiosaurs belong to the order of Marine Reptiles (Ennaliosaurians), which are highly important in Palaeontology. Along with Ichthyosaurs, Plesiosaurs swam the seas and rivers when the lands were peopled by other cold-blooded quadrupeds. They belong to the Lias, Oolite, and Wealden formations. These reptiles, along with Ichthyosaurs, are described as beautiful specimens found in the Lias limestones and shales.

General Characteristics

Plesiosaurians are notable marine reptiles. Their fossils are occasionally found in connection with parts of the skeleton, particularly the detached processes or articulated portions of vertebrae, mostly from the Lias limestones and shales. A notable feature of the teeth found in fossil reptiles is their implantation, and the source identifies the Plesiosaurus as having teeth implanted in a continuous groove or furrow.

Specimens in the British Museum (Room III)

The British Museum holds several significant specimens and casts of Plesiosaurs:

• Plesiosaurus dolichodeirus: This species, characterized by its long neck—which is nearly equal in length to the body and tail combined—is represented by the original specimen of this species. This original specimen is found on the top of Wall-case D. A cast of the Plesiosaurus Hawkinsii is also found in Case D.
• Plesiosaurus macrocephalus: A specimen of this species is located on the left side (or shelf E), obtained from the Lias by the Earl of Enniskillen.
• Plesiosaurus rugosus: Remains of this rare species are present, having been procured from the Lias near Belvoir Castle.
• Plesiosaurus hawkinsii: Exquisite specimens of the same species and parts of a Plesiosaurus dolichodeirus are exhibited on the upper shelves of Wall-case F.

Mantell describes the splendid skeletons of Plesiosauri spread out on slabs of grey limestone in Cases D and E, stating that they are in a condition that prevents their being easily recognised as organic remains by an uninstructed observer.

The Ichthyosauri (or Ichthyosaurs) are prominent members of the extinct order of Marine Reptiles (Ennaliosaurians). These reptiles swam the seas and rivers when lands were inhabited by other cold-blooded quadrupeds. They belong to the Lias, Oolite, and Wealden formations.

Location in the Museum

The principal location for Ichthyosaurs in the British Museum is Room IV. The synopsis for Room IV lists Ichthyosauri as a main part of its contents.

Ichthyosaurs are mentioned again in Room III (the room chiefly appropriated to Fossil Reptiles) as belonging to the Lias limestones and shales, frequently found preserved alongside Plesiosaurs.

Anatomical Characteristics

Teeth Implantation: The mode of implantation of their teeth is characteristic of fossil reptiles. Ichthyosaurs are noted for having teeth implanted in a continuous groove or furrow.

Osteological Arrangement: The Ichthyosaur is used as a reference point for anatomical comparisons with other fossil reptiles. For instance, the sclerotic coat protected by a zone of osseous plates, which is observed in the eyes of the extinct crocodile Geosaurus stemmeringii, is described as being “as in the Ichthyosaurus”.

The information provided regarding the Mosasaurus pertains to specimens displayed in Room III of the Gallery of Organic Remains at the British Museum.

The collection features a model of the celebrated specimen known as the Fossil Reptile of Maestricht. This model represents the Mosasaurus Hoffmanni, the original of which resides in the Jardin des Plantes. The model itself was presented to the author (Gideon Algernon Mantell) by Baron Cuvier.

Additionally, the museum houses two fine portions of the jaws, complete with teeth, belonging to this same species of gigantic reptile. These jaw portions were presented by Dr. Peter Camper in 1784. Other remains include vertebrae of Mosasaurus obtained from Maestricht and from the Chalk at Lewes. In the broader discussion of reptile anatomy, the location of the implantation of teeth in the Mosasaurus is highlighted as one of the distinctive modes observed in fossil reptiles.

Pterodactyls (or Pterodactyles) are classified as Flying Reptiles belonging to the extinct order of cold-blooded vertebrata featured in Room III of the British Museum’s Gallery of Organic Remains. The sources do not contain any reference to the term “Pterodons.”

Classification and Significance

Reptilian Nature: The osteological characters of gigantic Pterodactyls are noted as exclusively reptilian, and remnants previously supposed to belong to birds have been conceded to reptiles.

Geological Context: Specimens or models of Pterodactyles are associated with the Lias and the Oolitic strata (Solenhofen and Monheim).

Trackways: Tracks of small quadrupeds are considered referable to reptiles, possibly including pterodactylous species. The text notes that the existence of the winged bipeds, or Pterodactyles, warns us how easily the ornithic type might be approached and the essential characters of the Saurian being lost.

Anatomical Specimens and Size

Museum Specimens: Room III contains specimens of three species of Pterodactyles from Solenhofen: P. longirostris, P. brevirostris, and P. munsteri. There are also bones of Pterodactyles from the Wealden formation, a Pterodactyle specimen from Lyme Regis, and models of Pterodactyles from Monheim.

Gigantic Scale: Some Pterodactyl bones were of enormous size, suggesting a flying reptile equal in magnitude to the fabled Roc of Arabian story, and implying a wing expanse of ten or twelve feet from extremity to extremity.

Specific Anatomy: An upper jaw with teeth, belonging to a Pterodactyle, was obtained by Mr. Bowerbank; the head of the creature was estimated to have been sixteen or seventeen inches in length.

Mantell provides detailed coverage of the Notornis mantelli (Southern Bird), highlighting its identity, discovery, and physical characteristics, alongside its importance to palaeontology.

Summary of Coverage

1. Identity and Significance: The Notornis mantelli is referred to as the Southern Bird. Its acquisition is considered a matter of great interest because it was a new species previously known only by its fossil remains. The existence of the Notornis is noted as highly remarkable, echoing the discovery of the Dodo, which had been known only by tradition or bone. The species was first scientifically characterised by Professor Owen, based on the fossil bones obtained by Walter Mantell.

2. Discovery and Acquisition: Fossil bones belonging to the genus Notornis were established by Professor Owen and were found among other fossil bones collected by Walter Mantell in 1847. These relics are now housed in the British Museum.

The book also details the subsequent and highly important discovery of a live Notornis, which confirmed the existence of the species.

Fossil Remains: The bones of the Notornis were found in the menaccanite-sand deposits at Waingongoro, on the west coast of the North Island of New Zealand. The remains deposited in Table-Case 16 include the cranium, femur, tibia, and tarso-metatarsals of a bird of the Rail family, collected by Walter Mantell in 1847.

Live Specimen: The discovery of a live example of Notornis was made in a remote part of the South Island of New Zealand. The specimen was captured alive in November 1850. After its death four days later, the body was preserved and ultimately belonged to Dr. Mantell. The mounted specimen in Dr. Mantell’s possession is noted as the only one that had yet been seen. The anatomical characteristics of the skull of the Notornis were given in detail to the Zoological Transactions. The specific identity of the recent and fossil Notornis was confirmed by Mr. Gould.

3. Physical and Anatomical Description: The description of the Frontispiece (an illustration of the Notornis mantelli) details the bird’s appearance and structure:

It might be mistaken for a gigantic Porphyrio, but is generically distinct.

It is allied to Porphyrio in bill form and general colouring, and to Tribonyx in foot structure, but differs from both in its short wings and tail structure.

The bird is deprived by the feeble structure of its wings of the power of flight.

It has large, powerful hinder limbs and depends on its swiftness of foot to evade natural enemies.

The plumage is thick, and the great length of its back-feathers suggests it inhabits low and humid situations.

Colouring: Head, neck, and breast are purplish blue black; wings are rich deep blue; the bill and feet are bright red.

Dimensions: Total length is 20 inches [other dimensions omitted]

Page References

• p. ix: Description of the Frontispiece, titled “NOTORNIS MANTELLI”.
• p. 124: Reference page cited in the description of the Frontispiece regarding the Professor Owen’s description of the fossil bones.
• p. 125: Discussion of the Fossil Cranium of Notornis (Southern Bird) established by Professor Owen.
• p. 126: Reference page cited regarding the account communicated by Dr. Mantell to the Zoological Society of London about the discovery of a live specimen.
• p. 193: Bones of the Notornis Mantelli are listed as contained in Table-Cases 15, 16, and 17, along with Dinornis and Palapteryx.
• p. 289: Discussion of the beautiful bird, confirming the specific identity of the recent and fossil Notornis by Mr. Gould.

The New Zealand avifauna, both extinct and contemporary, shows several remarkable comparisons, particularly concerning the gigantic Moa (Dinornis) and the rare, struthious birds like the Apteryx and Notornis mantelli.

Comparisons of Notornis mantelli

The Notornis mantelli exhibits characteristics similar to other existing birds, though it is generically distinct:

• Porphyrio (Purple Coot/Sultana): Upon cursory view, the Notornis might be taken for a gigantic kind of Porphyrio. It is allied to Porphyrio in the form of its bill and in its general colouring. The general form of the Notornis skull approaches that of the Purple Coot. The structure of its tarsus-metatarsal is shortened and massive, similar to Porphyrio. The physical configuration suggests its habits and economy more closely resemble the Porphyrio than Tribonyx.
• Tribonyx: The Notornis is allied to Tribonyx in the structure of its feet.
• Apteryx (Kiwi-kiwi): The Notornis differs from both Porphyrio and Tribonyx in the shortness of its wings and the structure of its tail. The skeletal structure of the Notornis shows modifications similar to those found in the Brachypterygx, a short-winged Rail of New Zealand, and in the Apteryx. The sternum of Notornis is remarkably narrow and its keel is less prominent, suggesting a structure like that of the Brachypterygx or short-winged Rail of New Zealand. Professor Owen observed that the Notornis cannot be assigned to any known family but its osteological characters indicate a feasible development of wings.

• The discovery of the Apteryx, a rare struthious bird, led Professor Owen to observe the highly remarkable character of the existing fauna of the island.
• The extinction of the Moa and its kindred species is linked to the fate of the Dodo of the Mauritius.

Transcription of caption for frontispiece featuring Notornis

The description of the frontispiece, which features the Notornis Mantelli (Southern Bird), is extracted from Mr. Gould’s “Birds of Australia”:

“THE acquisition of a new species is always a matter of great interest; but when, as in the present instance, it is one so nearly extinct as to be only known to us previously by its fossil remains, the interest becomes enhanced to the highest degree. It is well known that the existence of the celebrated Dodo is all that tradition, or a bone which, but for Mr. W. Mantell’s fortunate acquisition of a living example, would probably have been shared by the present bird, the characters of which were first made known to us by Professor Owen, from the fossil bones obtained by that gentleman and sent home by the lamented explorer, after whom it is named; those relics are now in the British Museum. (See p. 124.)

That few living examples remain, is evident from the fact that the mounted specimen in Dr. Mantell’s possession is the only one that has yet been seen. All the information respecting it that has been obtained is comprised in the account communicated by Dr. Mantell to the Zoological Society of London, and published in their ‘Proceedings’ for 1850. (See p. 126.)

Upon a cursory view of this bird it might be taken for a gigantic kind of Porphyrio, but on examination of its structure it will be found generically distinct. It is allied to Porphyrio in the form of its bill and in its general colouring, and to Tribonyx in the structure of its feet, while in the shortness of its wings, and in the structure of the tail, it differs from both. From personal observation of the habits of the two recent genera above named, I may venture to affirm that the habits and economy of the present and more closely resembling those of the former than of the latter; that it is doubtless of a recluse and extremely shy disposition; that being deprived by the feeble structure of its wings of the power of flight, it has a compact to depend upon its swiftness of foot for the means of evading its natural enemies; and that, as is the case with Tribonyx, a person may be in its vicinity for weeks without even catching a glimpse of it. From the thickness of its plumage and the great length of its back-feathers, we may infer that it affects low and humid situations, marshes, the banks of rivers, and the courts of dripping ferns. In structure it is altogether peculiar. The tarsus-metatarsal is shortened and massive, like Porphyrio, it doubtless had the power of swimming, but it would seem from the structure of the legs to be more terrestrial in its habits than the members of that genus. I have carefully compared the bill of this bird with that figured by Professor Owen under the name of Notornis Mantelli, and have little doubt that they are referable to one and the same species.

Head, neck, and breast, upper part of the abdomen and flanks, purplish blue black, rump, upper tail-coverts, lesser wing coverts, and tertiaries, dark olive green, tipped with verditer green; at the nape of the neck is a band of rich blue separating the purplish blue of the neck, from the green of the body; wings rich deep blue, the greater coverts tipped with verditer green, forming crescentic bands when the wing is expanded; tail dark green; lower part of the abdomen, vent, and thighs, dull bluish black; under tail-coverts, white; bill and feet, bright red.

I cannot conclude these remarks without bearing testimony to the very great attention of the reader, which have attended the researches of MR. WALTER MANTELL, in the various departments of science, to which he has turned his attention, nor without expressing a hope that he may yet be enabled to obtain some elucidation as to the history of this and the other remarkable birds of the country in which he is resident.

The plate accompanying this description represents the Notornis in two positions, of the natural size, and accurately coloured.”

Trackways (or fossil footprints) are featured prominently in the text, particularly in Room I of the British Museum’s Gallery of Organic Remains, where they are presented as highly instructive examples of petrifaction. The study of these tracks gained significant interest about twenty years prior to the book’s publication, especially from the discovery of footprints on the exposed surfaces of slabs of Triassic sandstone.

Importance of Trackways in Palaeontology

The author views the tracks as exceptionally important, alongside other vestiges of organic structure in rocks. They are considered”autographies inscribed on the rocks and strata” by countless myriad of extinct beings, providing direct records of their progress, which are sometimes even more enduring than the organisms’ own skeletal remains.

Trackways allow scientists to deduce aspects of ancient environments and the physical characteristics of extinct animals, sometimes offering instruction where actual bones are unknown.

Trackway Collections in the British Museum

The collection in Room I features several remarkable trackway specimens, primarily from the Triassic sandstone:

1. Footprints of Birds (Ornithichnites):

A splendid example of bipedal footprints, provisionally supposed to be those of Birds, is found on Triassic sandstone from Turner’s Falls, Massachusetts, United States.

This large slab is 8 feet by 6, and contains the track-marks of ten or twelve individuals of various sizes. These impressions are noted for having been deeply impressed upon plastic mud, which later hardened into stone, preserving the details of the feet.

The Ornithichnites (footprints of birds on stone) found in the valley of the Connecticut River, Massachusetts, occur in many localities, sometimes extending upwards of eighty miles.

Professor Hitchcock observed over thirty-two species of bipeds and twelve of quadrupeds in the valley of the Connecticut, sometimes appearing on the surface of superimposed strata over 1,000 feet deep. The largest bird footprints indicate a stride length far exceeding that of any known living biped, including the Ostrich. The discovery of the gigantic Moa (Dinornis) helped reconcile the size of these tracks.

2. Footprints of Quadrupeds (Chirotherium):

The collection includes a large slab with foot-tracks of a supposed reptilian quadruped named Chirotherium. These hand-like impressions originated from Triassic sandstone near Storton quarries, Liverpool.

Two further slabs displaying footprints of a similar character are exhibited in the wall case, originating from the Triassic deposits at Hildburghausen in Saxony.

The quadrupedal ichnolites (Chirotherium) exhibit a disproportion where the hind feet are nearly twice the size of the fore feet. This characteristic suggests a possible relation to marsupial mammalia or batrachian reptiles.

The appearance of five claws was observable on each fore-paw.

Scientific Interpretation

The tracks revealed phenomena such as ripple-marks, cracks, and the impressions of rain-drops that fell while the surface was soft. The discussion around Labyrinthodonts noted the conjecture that the largest Chirotherium tracks must have been produced by these colossal Batrachians. However, connecting the Labyrinthodonts with the hypothetical Chirotheria remains conjectural, as the bones of the track-makers have not been definitively determined.