The Country of the Iguanodon, by Gideon Mantell – Two Versions

Compare two versions of Gideon Mantell’s “The Country of the Iguanodon”. The first version appeared in 1838; the second, in 1851. Mantell (1838) shows an effort to reconstruct palaeoclimate, fauna, and flora operating as an integrate whole. Mantell (1851) continues these but adds comments on taphonomy and deposition. Both are important attempts to understand the living world of a singular moment in deep time. It is an imaginative, living space.

Below are complete transcriptions for the two sections, with original texts embedded in the toggled sections. Notes in [square brackets] are editorial or mark page transitions. 

John Martin’s 1837 painting, “The Country of the Iguanodon,” is widely available online, such as via Bridgeman Education and Google Arts and Culture and the locally-invested Cuckfield Connections. The original is in the Museum of New Zealand | Te Papa Tongarewa. Note the scale of the animals as well as the detail in foreground and background.

Gideon Mantell (1838) The Wonders of Geology

[p. 368] 53. The Country of the Iguanodon.- By this survey of the strata and organic remains of the Wealden, we have acquired date from which, by the principles of induction explained in a former lecture (page 34), we may obtain secure conclusions as to the nature of the country from whence those spoils were derived, the animals by which it was inhabited, and the vegetables that covered its surface. That country must have been diversified by hill and dale, by streams and torrents, the tributaries of its mighty river. Arborescent ferns, palms, and [368/369] yuccas, constituted its groves and forests, delicate ferns and grasses, the vegetable clothing of its soil; and in its marshes, equiseta, and plants of a like nature, prevailed. It was peopled by enormous reptiles, among which the colossal Iguanodon and the Megalosaurus were the chief. Crocodiles and turtles, flying reptiles and birds, frequented its fens and rivers, and deposited their eggs on the banks and shoals; and its waters teemed with lizards, fishes, and mollusca. But there is no evidence that Man ever set his foot upon that wondrous soil, or that any of the animals which are his contemporaries found there a habitation: on the contrary, not only is evidence of their existence altogether wanting, but from numberless observations made in every part of the globe, there are conclusive reasons to infer, that man and the existing races of animals were not created, till myriads of years after the destruction of the Iguanodon country – a country, which language con but feebly portray, but which the magic pencil of a Martin, by the aid of geological research, has rescued from the oblivion of countless ages, and placed before us in all the hues of nature, with its appalling dragon-forms, its forests of palms and tree-ferns, and all the luxuriant vegetation of a tropical clime.* [369/end]

* – See the Frontispiece; an engraving on steel, from an original painting of John Martin, Esq., K.L.

Source: Gideon Mantell (1838) The Wonders of Geology, pp. 368-369.

“The Country of the Iguanodon” from Gideon Mantell (1851) Petrifactions and Their Teaching

“We have now examined [335/336] the principal specimens of the terrestrial plants and animals of the Wealden formation of the south-east of England, that are contained in the British Museum, and I will conclude this section of the present chapter with some general remarks on the physical geography, and the nature of the fauna and flora, of the Country inhabited by the stupendous reptiles, whose fossil remains have so long engage our attention. 

From the nature of the alluvial sediments accumulated in the lapse of innumerable ages in the deltas and estuaries, which now constitute a great part of the area of the southeast of England, and of the north of Germany, a general idea may be obtained of the aspect of the country through which the river flowed, and the character of the superficial strata; and from the fossil remains we may learn the nature of the trees and plants which clothed its soil, and of the animals that roamed over the land, or inhabited the waters.

Whether that country were an Island or a Continent cannot be determined; but that it was diversified by hills and valleys, and irrigated by streams and rivers, and enjoyed a climate of a higher temperature than any part of modern Europe, is most evident. Coniferous trees in all probability clothed its alpine regions; palms, arborescent ferns, and cycadeous plants, constituted the groves and forests of its plains and valleys; and in its fens and marshes the equisetaceae, and plants of a like nature, prevailed. That the soil was of a sandy character on the hills and elevated grounds, and argillaceous in the plains and marshes, may be inferred from the vegetable remains, and the materials in which they were imbedded. Sands and clays every where prevail throughout the Wealden formation, and have probably resulted from the decomposition of micaceous and felspathic rocks. 

Some influences also may be drawn as to the prevailing atmospheric condition of the country, from the undulated surfaces of the laminated sandstones and shales, and from the stems of the fossil trees. In the former we have proof, that when the land of the Iguanodon existed, the water was rippled by the breezes which then, as now, varied in intensity and direction in a brief space: from the latter we learn that in certain situations the wind blew from a particular quarter for a great part of the year, and that the mean annual temperature was as variable as in modern times. [336/337]

If we attempt to portray the vertebrated animals of that unknown country, our description will partake more of the character of a romance of the fabulous ages, than of a legitimate deduction from established facts. Turtles of various kinds must have been seen on the banks and in the waters of its rivers and lakes, and groups of enormous crocodiles basking in its fens and marshes. The colossal Megalosaurus and Pelorosaurus, and yet more marvellous Iguanodon, to whom the grooves of clathrariae and arborescent ferns would be mere beds of reeds, must have been of such prodigious magnitude, that the existing animal creation presents us with no fit objects of comparison. Imagine an animal of the lizard tribe, three or four times as large as the largest alligator, with jaws and teeth equal in size to those of the rhinoceros, and with legs as massive in their proportions as the limbs of the elephant – such a creature must have been the Iguanodon.

From what has been advanced, it must not, however, be supposed, that the country of the Iguanodon occupied the site of the South-East of England, and that the animals and terrestrial plants of the Wealden lived and died near the area where they relics are entombed; for, with the exception of the shells and crustaceans, and certain marsh and aquatic plants, all the fossil remains bear unequivocal marks of having been transported from a great distance. But though three-fourths of the bones discovered have evidently been broken and rolled before their deposition, the teeth detached from their sockets, the vertebrae, and the bones of the extremities, with but very few exceptions, disjointed and scattered here and there, the stems and branches of the trees torn to pieces and stripped of their foliage,- there is no intermixture of sea-shells, nor of beach or shingle: these remains have been subjected to abrasion from river currents, but not to attrition from the waves of the ocean.

The gigantic limbs of the large saurian could not have been dissevered from their sockets without great violence, except by the decomposition of their tendons from long maceration in water; ad if the latter were alone the cause of the dislocation of the bones, we should not find them broken and waterworn, but lying more or less in juxtaposition, as is the case in the skeletons of the marine reptiles of the liassic deposits. But the condition in which the fossil relics of the [337/338] Wealden occur, proves that they were floated down the streams and rivers, with rafts of trees and other spoils of the land, till, arrested in their course, they sank down and became buried in the fluviatile sediments then in progress. 

The state of the first discovered specimen of the Hylaeosaurus is in this point of view highly instructive: many of the bones are crushed and splintered, yet the fractured portions remain near each other; the vertebrae are more or less displaced, yet they maintain relation to the positions they originally occupied; the bones of the fore-legs have been torn from their sockets, and this must have taken place before the specimen was imbedded in the mud and sand, for the glenoid cavities were filled with stone: these facts prove that the carcass of the original must have undergone mutilation before the bones were reduced to a skeleton; and that the dislocated and broken parts were held together by the muscles and integuments; in this state the trunk was borne down the stream, and at length sank into the mud of the delta, and formed a nucleus around which the stems and leaves of cycadeous plants and ferns were accumulated, and river shells became intermingled in the general mass.

The phenomena here contemplated cannot, I conceive, be satisfactorily explained upon any other supposition than that which implies a long transport, by the agency of streams and currents: the carcasses of the colossal reptiles must have been exposed to such an action for a considerable time, and the source of the mighty river which flowed through the Country of the Iguanodon, must, therefore, like that of the Mississippi, have been far distant from the delta which in the course of innumerable ages accumulated at its mouth.1″ [338/end]

1. See “Wonders of Geology,” p. 444, and pp. 483-490.

Source: Gideon Mantell (1851) Petrifactions and Their Teaching: A Hand-book to the Gallery of Organic Remains of the British Museum, pp. 335-338.

Editorial note: “Pelorosaurus” is described as a colossal reptile so immense that existing animal creation offers no fit objects of comparison. It was thought by Mantell to be one of the huge Saurians that inhabited the Country of the Iguanodon. Fossils referred to this genus include four splendid plano-concave vertebrae, which were designated Pelorosaurus conybeari (Mantell 1851: 142, citing Mantell (1850)), subsuming Cetiosaurus brevis (Owen 1841). The complicated unravelling of this material is described by Stewart (2016), who describes Pelorosaurus as a brachiosaur.