Re: Hello and a question about Iguanodon mantelli (long)

[Dinogeorge@aol.com]

In a message dated 97-08-16 13:41:51 EDT, you write:

<< Gideon Mantell (or probably his wife) found the first Iguanodon tooth
 and described it (he tried to call it Iguanosaurus but this name was
 already occupied).  He also got possession of 'The Maidstone Slab' which
 is still in the Natural History Museum in London, as a slab.  I believe
 that this slab was made the type specimen for Iguanodon mantelli Meyer
 1832(?) and this was accepted by contemporary palaeontologists like
 Lydekker.  My question is - when did Iguanodon mantelli disappear - I
 don't mean the slab or the tooth - but the name?  It now seems to be
 part of Iguanodon atherfieldensis Hooley 1925 (see The Dinosauria).  The
 type specimen of atherfieldensis was not even found until the 1920's,
 so, it they are the same species, surely it should be referred to
 mantelli? >>

You may find these excerpts from my article on ornithopod origins and
evolution useful (sorry, figures unavailable). Eventually these will be
incorporated into a volume of _Historical Dinosaurology_ on the origin and
evolution of the ornithopods.

The first ornithischian dinosaurs identified in the fossil record were
ornithopods, and were it not for the large theropod Megalosaurus, ornithopods
would have been first of all the major dinosaur groups with a scientifically
described member. As the story goes, in the spring of 1822, Mary Ann
Woodhouse Mantell presented her husband, Dr. Gideon Algernon Mantell, a
surgeon then residing in Lewes, Sussex, with several puzzling, worn fossil
teeth she had picked out of a pile of rubble at a road-construction site
while he was visiting a patient near Cuckfield in Sussex. Although in the
medical profession, Mantell had a deep interest in fossils and was already
one of England's best-known fossil-collectors; he immediately recognized the
teeth as unusual. They were imbedded in calcareous grit from a nearby Tilgate
Forest quarry whose location Mantell, to keep competing collectors from
raiding his turf, never divulged. (Much later, William E. Swinton, in his
1970 book The Dinosaurs, confidently identified it as a now filled-in quarry
near Wightman's Green, Sussex.) Mantell mentioned the find in print for the
first time in the preface, dated May 1, 1822, to his huge 320-page book The
Fossils of the South Downs; or, Illustrations of the Geology of Sussex.
        Shortly thereafter, at a meeting of the Geological Society of London,
Mantell passed the best tooth around to fellow British fossil-collectors,
including the Reverends William Buckland and William Daniel Conybeare,
William Clift, and Thomas Vernon Wollaston, for possible identification. His
idea that it might have belonged to a large, previously unknown herbivorous
reptile found little support among the members, who eventually decided the
tooth belonged to either a large fish or a Pleistocene mammal. According to
Mantell's later account (in Petrifactions and Their Teachings; or, a
Hand-book to the Gallery of Organic Remains of the British Museum, 1851),
only Wollaston allowed the possibility that it was reptilian.
        Unconvinced, Mantell sent the tooth via Charles Lyell to Paris, where
Europe's foremost anatomist, the Baron Jean Léopold Chrétien Frédéric
Dagobert (better known as Georges) Cuvier, examined it and pronounced it the
upper incisor of a rhinoceros. Unconvinced, Mantell sent Cuvier metacarpal
bones from the same locality, and Cuvier identified them as the foot bones of
a hippopotamus. After paying Tilgate quarrymen to look for more teeth,
Mantell was soon able to send Cuvier several, including one complete and
unworn. On June 20, 1824, Cuvier reconsidered his identifications and wrote
Mantell his famous letter admitting his error and averring that the teeth
most likely did belong to a wholly new kind of giant reptilian herbivore.
        Mantell, meanwhile, "ransacked"--in his words--the collection of the
Hunterian Museum at the Royal College of Surgeons in London for more of the
strange teeth. There Samuel Stutchbury drew his attention to a newly prepared
iguana skeleton, and Mantell was pleased to see that his fossil teeth
resembled gigantic versions of the lizard's tiny teeth. As he noted in a
letter dated November 13, 1824 to Cuvier, he decided to name his new fossil
reptile Iguanosaurus ("iguana lizard"). Conybeare, however, quickly advised
him to use the more appropriate Iguanodon ("iguana tooth"). Mantell's
illustrated description, titled "Notice on the Iguanodon, a newly discovered
fossil reptile, from the sandstone of Tilgate Forest, in Sussex," appeared in
the 1825 volume (115) of the Philosophical Transactions of the Royal Society
of London. Just as the slightly earlier name Megalosaurus inspired a host of
dinosaur names ending in -saurus (of which Iguanosaurus was the first!), so
did Iguanodon inspire a multitude of dinosaur names ending in -odon, such as
Deinodon, Trachodon, Troodon, Rhabdodon, and Hypsilophodon. Usually, dinosaur
names ending in -saurus are based on fossil bones, while names ending in
-odon are based solely on fossil teeth, or include teeth among their most
distinctive remains.
        Interestingly, Mantell's earlier name Iguanosaurus leaked out in an
anonymous news note in the December 1824 issue of New Monthly Magazine,
months before Mantell formally published the name Iguanodon. It was picked up
and used as a synonym of Iguanodon in works by Ferdinand August von Ritgen
(1828) and F. Holl (1829), of whom the former is sometimes credited with
first usage of Iguanosaurus. Lacking a scientific description, however,
Iguanosaurus is technically a nomen nudum and ineligible to replace the name
Iguanodon, even though it was published first and was employed in subsequent
scientific works.
        Iguanodon first appeared in print as a genus without a type species.
Although this would have made it, too, a nomen nudum had today's
nomenclatural rules been in force, such generic names were then considered
available--and still are, if created before 1931. The first work explicitly
naming a species of Iguanodon was the 1829 tome by Holl, volume I of the
Handbuch der Petrifaktenkunde, in which the teeth described by Mantell were
called Iguanodon anglicum (the "English" Iguanodon). (Because the generic
name is masculine, not neuter, the trivial name must be respelled anglicus,
which was first done in print, as far as I know, in 1850 by German naturalist
Heinrich Georg Bronn.) As the first-named species of Iguanodon, Iguanodon
anglicus became the type species of the genus, and the teeth Mantell
originally described became lectotype specimens of the species. Five of the
teeth remain in the collection of the Natural History Museum at London: BMNH
2390-2394, of which BMNH 2392 is the actual lectotype and the others are
paralectotypes. They were purchased, along with a vast collection of other
dinosaur fossils, from Mantell on March 4, 1839; he received payment from the
British government the following August.
        Based as it is on teeth (Figure 5), Iguanodon would almost automatically
qualify as a doubtful genus. But a considerable number of skeletal elements
have accumulated from the same geological horizon and even the same quarries
as the teeth. There is evidence that Iguanodon bones were found by Mantell
and Buckland even before the teeth, but misidentified as non-reptilian. Many
of these topotype specimens undoubtedly belong to Iguanodon anglicus and may
serve to augment the diagnosis of the species. Thus, there is presently no
reason to reject the genus Iguanodon as doubtful. The genus and the referable
material have not yet been reviewed from a modern standpoint, however; such a
review has been in progress for more than a decade by British paleontologist
David Bruce Norman, and owing to the vast number of available specimens it
may be some years yet before it is published. Surely, among the material that
has over the past 170 years been referred to Iguanodon there are specimens
belonging to other ornithopod genera; and one or two genera customarily
synonymized with Iguanodon may in fact be valid and distinct. I will offer
opinions about such situations as I come to them in this review.
        To return to the story, Mantell went back to the Tilgate quarries
repeatedly, and over the next several years accumulated hundreds of Iguanodon
teeth and isolated bones of the same beast. He soon found the peculiar
"thumb" of Iguanodon, which he imagined was the animal's nasal horn core, and
he found pelvic bones, some of which he thought were part of the shoulder
girdle. And he found other kinds of dinosaurs; in 1832, for example, he
turned up a substantial portion of the skeleton of the spiny herbivorous
dinosaur Hylaeosaurus armatus. This discovery he described in 1833.
        Meanwhile, in 1832, German paleontologist Christian Erich Hermann von 
Meyer
published an account of Iguanodon teeth in a widely circulated 560-page
treatise titled Palaeologica zur Geschichte der Erde und ihrer Geschöpfe.
Overlooking Holl's work, von Meyer named the teeth Iguanodon mantelli, and
this became widely known during the 19th century as the "type" species of
Iguanodon. But as pointed out by Norman, despite its widespread usage,
Iguanodon mantelli remains a junior objective synonym of Iguanodon anglicus,
because both names are based on the same series of specimens (teeth). So I
use Iguanodon anglicus as the name of the Tilgate Grit Iguanodon throughout
this review.

------- (Here I've omitted some out of date material on Hikanodon, the
earliest junior synonym of Iguanodon)

        In February 1834, an outstanding specimen of Iguanodon was unearthed by 
men
working a Shanklin Sand quarry owned by William Harding Bensted, at Maidstone
in Kent. Part of the specimen was blown apart by gunpowder and scattered
during blasting operations, but a considerable portion (Figure 6) survived on
a large slab of "Kentish Rag" sandstone about 2x2 meters in size. Bensted
himself chiseled the slab and its cargo of giant bones out of the quarry. In
due time, he published a short account of the discovery in a small, privately
printed volume of literary and other works by himself and his dining-club
colleagues (the complete narrative is reprinted in Swinton's 1970 book The
Dinosaurs).
        Bensted acquired local fame for his discovery before writing to 
Mantell, who
had by then moved his practice to Brighton, about 40 miles southwest of
Maidstone. On June 4, 1834, after a pleasant coach trip from London, Mantell
spent the evening examining the fossil. The associated teeth allowed him to
identify it at once as an Iguanodon (Bensted had been unable to identify it
himself). He offered £10 for the slab. Bensted, realizing the importance of
his find, held out for £25, and it was not until August 14 that Mantell's
friends pooled their resources and purchased the "Mantell-piece" (as they put
it) for Bensted's asking price. Edwin Harris Colbert, in his book Men and
Dinosaurs, quoting an earlier paper by Swinton, noted that in 1949 the town
of Maidstone acquired an official coat of arms on which a life restoration of
Iguanodon was emblazoned.
        The Maidstone Iguanodon was the first instance in which a large number 
of
bones of an individual dinosaur were found together in positive association.
Although they are terribly jumbled, they allowed the British
fossil-collectors to identify many previously found isolated bones as
Iguanodon. They also allowed Mantell to attempt a reconstruction in 1835 of
the animal's skeleton. His vision of Iguanodon as a gigantic, herbivorous
lizard 30 and even 60 meters long astonished the world's paleontologists and
inspired them to collect vertebrate fossils with intensity and passion. Later
discoveries and research greatly downsized Mantell's spectacular estimates of
its dimensions, but even modern reconstructions give Iguanodon anglicus the
body size of an adult elephant. With tail, it approached 9 meters in length
and about 3-5 tonnes in mass (Figure 7).
        Incidentally, it is not at all certain that the Maidstone specimen 
belongs
to Iguanodon anglicus. Its type locality is thought to be significantly
higher in the Wealden Formation than the Tilgate Grit quarry from which
Mantell's original Iguanodon teeth came. Richard Lydekker, in his 1888
catalogue of fossil reptile specimens in the British Museum, designated the
Maidstone skeleton as the lectotype specimen of Iguanodon mantelli, but
nobody has accepted this because, besides being from an earlier geological
horizon, Iguanodon mantelli had been named two years before the Maidstone
skeleton was discovered! If it turns out that the Maidstone specimen does
belong to a different Iguanodon species, it may require a new specific name.
        The idea that Iguanodon was not merely a scaled-up lizard but a 
genuinely
new kind of prehistoric creature was put forward by Britain's most renowned
comparative anatomist, the choleric and underhanded but brilliant Sir Richard
Owen. In early April 1842, the published version of his lengthy August 2,
1841 lecture on British fossil reptiles to the British Association for the
Advancement of Science (at Plymouth) appeared, containing his original
description of the "sub-order" Dinosauria. He hadn't used the term in his
lecture because at the time he hadn't yet thought of it; only later, when he
actually composed his lecture notes into publishable form did he realize that
dinosaurs formed a special reptilian subgroup requiring its own name.
        Owen included three genera in Dinosauria: Buckland's Megalosaurus and
Mantell's Iguanodon and Hylaeosaurus. These were unlike any other reptiles
then known, Owen contended, in having an erect rather than a sprawling
posture. This was demonstrated by their larger number of sacral vertebrae
(five) and by the shapes and articulations of their massive limb bones. When
in 1852 the celebrated Crystal Palace, a lacy structure of iron and glass,
was disassembled and moved from its original site in London's Hyde Park to
suburban Sydenham, Queen Victoria's husband Prince Albert suggested that
life-size models of prehistoric animals be erected on the grounds. Benjamin
Waterhouse Hawkins, an artist and sculptor, was hired to build them according
to Owen's specifications: as large, rhinocerine quadrupeds. On December 31,
1853, Britain's best-known paleontologists supped inside Hawkins's almost
finished Iguanodon, a happening widely reported in the British press. That
modern reconstructions of Megalosaurus and Iguanodon scarcely resemble their
Victorian counterparts shows how little science of that day knew about those
dinosaurs, despite the accumulating wealth of available specimens and the
hubris with which life restorations were hypothesized. Owen, incidentally,
was not responsible for retaining the Iguanodon "thumb" on the snout of
Hawkins's model. It was he himself who first determined it belonged on the
hand as a "carpal spine," but unfortunately he did so too late for the change
to be incorporated. Hawkins's dinosaurs and other prehistoric animals still
stand and may be viewed by visitors today, though the palace itself burned to
the ground in 1936.
        The erect stance of Iguanodon as determined by Owen evidently impressed
Austrian naturalist Leopold Joseph Fitzinger, who in 1843 produced a
compendious Latin tome titled Systema Reptilium, classifying all the
then-known reptilian genera and species. This work has become notorious for
incorporating numerous useless first appearances of generic names whose sole
function is seemingly to preempt later usages by unsuspecting authors. Ther
is the classical Greek stem-word employed for mammals in zoology, and
Fitzinger used the name Therosaurus mantelli for Iguanodon mantelli. Perhaps
he considered "mammal lizard" a more appropriate name for Iguanodon because
of Owen's assertion that it and the other dinosaurs resembled erect large
mammals, not sprawling small reptiles, in their posture. He classified Owen's
dinosaurs in the reptilian group Therosauri as well (and for no stated reason
changed the spelling of Mantell's Hylaeosaurus to Hylosaurus). Fitzinger's
name Therosaurus was rejected through disuse and synonymy and has only
historical interest today.
        England turned out to be positively littered with disarticulated 
Iguanodon
specimens, which British paleontologists collected, (mis)identified, and
catalogued with gusto during subsequent decades. Owen's species Cetiosaurus
brachyurus (1842), Streptospondylus major (1842), Streptospondylus recentior
(1851), and Streptospondylus meyeri (1854) were all based on Iguanodon
material more or less indeterminate at the species level. (At the time,
Streptospondylus itself was misidentified as a crocodilian; it is actually a
theropod dinosaur.) France, too, entered the fray with remains unearthed by
paleontologist Jacques Cornuel and described by him in 1850 as a new genus
and species of dinosaur, Heterosaurus neocomiensis ("different lizard from
the Neocomian": so called because its teeth differed from those of Iguanodon,
Hylaeosaurus, and Megalosaurus and supposedly required a new genus; Figure
8). These he had found in a quarry in the marine Calcaire à Spatangues
(Hauterivian) near Wassy, Haute-Marne province. Mixed with plesiosaur
teeth--the nondinosaurian "different" teeth--were the scattered bones of a
medium-size Iguanodon skeleton, to date one of the best-preserved dinosaurs
ever found from the Early Cretaceous of France. Briefly noted by G. Corroy in
1922, Heterosaurus neocomiensis remained largely forgotten as a doubtful
taxon with a composite type specimen for more than a century, until 1968,
when it was tersely redescribed by Albert F. de Lapparent and Vladimir
Stchepinsky. Now stored at the Saint-Dizier Museum, Cornuel's material, as
well as other French Iguanodon material, was thoroughly and completely
redescribed in 1992 by Valérie Martin and Eric Buffetaut of the Université
Paris. They concluded that Heterosaurus neocomiensis most closely resembles
Iguanodon atherfieldensis among the currently valid species in that genus.
Should this suggested synonymy be accepted, the trivial name atherfieldensis
would have to be abandoned in favor of neocomiensis.
        Mantell's personal story came to a rather gloomy end, shortly before the
Crystal Palace models were constructed. Obsessed with dinosaurs, Mantell
immersed himself during the three decades following the discovery of the
Iguanodon teeth in studying and writing about them, neglecting his medical
and surgical practice. His son Walter Baldock Durrant Mantell emigrated to
New Zealand in 1840, where he studied moas and became Minister for Native
Affairs, Postmaster General, and Secretary for Crown Lands. In later years,
Mantell sent him "the first Iguanodon tooth he ever found," which perhaps
still resides somewhere in New Zealand. Mantell's books on fossils and
geology never sold well, and today they are quite rare outside libraries.
Despite several large sales of his fossil collections to the British Museum,
he never managed to make a living from paleontology, and this eventually
forced his wife and remaining children to leave him. He died November 10,
1852, crippled by a spinal injury, embittered and alone.