Mary Mantell and the lithographed of an Iguanodon teeth.
On 10 February 1825, Gideon Algernon Mantell’s paper “Notice on the Iguanodon, a newly discovered fossil reptile from the sandstone of Tilgate Forest” was read by Davies Gilbert MP at a meeting of the Royal Society of London.
In the paper, Mantell gives a brief description of the characteristics of the sandstones of Tilgate Forest. He also gives details of the help given by George Cuvier. At first, Cuvier suggested that the teeth found in a Sussex quarry belonged to a rhinoceros. However, in a letter written in 1824, he admitted his error and stated that the remains were reptilian and probably belonged to a giant herbivore. At Cuvier’s suggestion, Mantell visited the Hunterian Museum (at the Royal College of Surgeons in London) in search of the jaws and teeth of living reptiles. Almost a year later, Mantell described them and named them Iguanodon (‘iguana tooth’) because of their resemblance to those of living iguanas. Mantell even acknowledges the valuable assistance of William Clift, curator of the Hunterian Museum. Still, the work does not mention his wife Mary Mantell, who discovered those fossils during a walk in the Tilgate woods in 1822.
Illustration of Iguanodon teeth next to those of a modern iguana published in Mantell’s 1825 work. Source: Wikipedia.
Mary Ann Woodhouse Mantell was born on 9 April 1795. She married Dr. Gideon Mantell in 1816. Between 1818 and 1822, Mary collaborated with her husband illustrating Mantell’s work: “Fossils of the South Downs: or Illustrations of the Geology of Sussex.” She also made the illustrations of the first teeth found, which appear in “Notice on the Iguanodon, a newly discovered fossil reptile from the sandstone of Tilgate Forest”.
Iguanodon tooth in the Te Papa Museum, New Zealand, donated by the Mantell family. From Simpson, 2020.
Recent research has uncovered a publication in the Mid Sussex Times dated Tuesday 1 November 1887 detailing Mary’s involvement in the discovery of the Iguanodon tooth. According to the publication, Mrs. Mantell was visiting her friend Mrs Waller, wife of Mr S Waller, a solicitor, of Cuckeld, when she found a man by the roadside breaking up pieces of stone; when Mary noticed what appeared to be a fossil in one of the stones, she stopped to examine it. After giving the man a tip, she took the fossil home for her husband to examine.
The controversy over Mary’s involvement in the discovery of the Iguanodon seems to be the result of the scandalous divorce between Mary and Gideon Mantell, who in revenge asked his son Walter to erase from his diaries any mention of Mary and her collaboration in his work.
Mary Mantell died on the 20th of October 1869 at her home in Chepstow Villas, Bayswater, London.
References:
Mantell, G. A. (1825). VIII. Notice on the Iguanodon, a newly discovered fossil reptile, from the sandstone of Tilgate forest, in Sussex. By Gideon Mantell, FLS and MGS Fellow of the College of Surgeons, &c. In a letter to Davies Gilbert, Esq. MPVPRS &c. &c. &c. Communicated by D. Gilbert, Esq. Philosophical Transactions of the Royal Society of London, (115), 179-186.
BUREK, C. V. & HIGGS, B. (eds) The Role of Women in the History of Geology. Geological Society, London, Special Publications, 281, 1–8. DOI: 10.1144/SP281.1.
Cadbury D 2001. The Dinosaur Hunters. A story of scientific rivalry and the discovery of the prehistoric world. Harper Collins, London.
Phylogeny of bird-line archosaurs and the hierarchical evolutionary acquisition of a bird-like phenotype. From Field et al., 2025.
In April 1842, Owen created the group “Dinosauria” using three taxa: Megalosaurus, Iguanodon, and Hylaeosaurus, based on three main characters: large size and terrestrial habits, upright posture, and sacrum with five vertebrae (because the specimens were all from the Late Jurassic and Cretaceous): “The combination of such characters, some, as it were, from groups now distinct from each other, and all manifested by creatures far exceeding in size the largest of the existing reptiles, will, it is presumed, be considered sufficient ground for the establishment of a distinct tribe or suborder of Saurian reptiles, for which I would propose the name of Dinosauria.”(Richard Owen, “Report on British Fossil Reptiles.” Part II. Report of the British Association for the Advancement of Science, Plymouth, England, 1842).
In the summer of 1861, two years after the publication of the first edition of Darwin’s Origin of Species, workers in a limestone quarry in Germany discovered the imprint of a single 145-million-year-old feather. On September 30, 1861, German paleontologist Hermann von Meyer wrote: “I have heard from Mr. Obergerichtsrath Witte that the almost complete skeleton of a feather-clad animal had been found in the lithographic stone. It is reported to show many differences with living birds. I will publish a report of the feather I inspected, along with a detailed illustration. As a denomination for the animal I consider Archaeopteryx lithographica to be a fitting name.”
When Andreas Wagner, Director of the Paleontological Collection of the State of Bavaria in Germany, examined the fossil, he concluded that it was a reptile and gave it the name Griphosaurus. He wrote: “Darwin and his adherents will probably employ the new discovery as an exceedingly welcome occurrence for the justification of their strange views upon the transformations of animals.”
Archaeopteryx lithographica, specimen displayed at the Museum für Naturkunde in Berlin. (From Wikimedia Commons)
The most important discovery to emerge from 200 years of extensive dinosaur research is the revelation that Dinosauria includes all birds, living and extinct. In recent years, several discovered fossils of theropods and early birds have filled the morphological, functional, and temporal gaps along the line to modern birds. Most of these fossils are from the Jehol Biota of northeastern China and date from about 130.7 to 120 million years ago.
Those findings demonstrate that distinctive bird characteristics such as feathers, flight, endothermic physiology, unique strategies for reproduction and growth, and a novel pulmonary system have a sequential and stepwise transformational pattern, with many arising early in dinosaur evolution, like the unusually crouched hindlimb for bipedal locomotion,the furcula and the “semilunate” carpal that appeared early in the theropod lineage (Allen et al., 2013; Xu et al., 2014).
Brain size has been correlated with major evolutionary innovations like cognition, flight, environmental adaptability and enhanced sensory capabilities. Due to the volumetric expansion of key brain regions, particularly the telencephalon (cerebrum) and cerebellum, the brain of crown birds is larger and more globular than that of other reptiles.
Skull of the holotype of N. hestiae (MPM-200-1) in left lateral view. Scale bar: 10 mm. From Chiappe at al., 2024.
Enantiornithes are the most diverse group of Mesozoic birds. The clade displays a mosaic of characters, reflecting their intermediate phylogenetic position between the basal-pygostylians and modern bird, and their remains, ranging from the size of hummingbirds to turkeys, have been collected on every continent except Antarctica. The discovery of an exceptionally well preserved braincase from an Upper Cretaceous (~80 Ma) enantiornithine bonebed in southeastern Brazil shed light on the early evolution of the avian braincase, brain and inner ear.
The crownward euornithine also exhibit mportant palatal innovations, as illustrated by representatives of the clades Ichthyornithes and Hesperornithes. Those novelties are essential for understanding the origin and refinement of avian cranial kinesis.
Sciurumimus (A); the basal coelurosaur Sinosauropteryx (B) with filamentous feathers; the deinonychosaurs Anchiornis (C) and Microraptor (D). Adapted from Xu et al., 2014.
Feathers were once thought to be unique avialan structures. Primitive theropods, such as Sinosauropteryx and the tyrannosaurs Dilong and Yutyrannus, and some plant-eating ornithischian dinosaurs, such as Tianyulong, and Kulindadromeus are known from their spectacularly preserved fossils covered in simple, hair-like filaments called ‘protofeathers’. Other integumentary filaments, termed pycnofibres, have been reported in several pterosaur specimens. The discovery of integumentary structures in other pterosaurs, such as Pterorhynchus wellnhoferi (a rhamphorhynchoid pterosaur), and other exquisitely preserved specimens from China, suggest that all Avemetatarsalia (the wide clade that includes dinosaurs, pterosaurs, and close relatives) were ancestrally feathered.
The evolution of flight involved a series of adaptive changes at the morphological and molecular levels, like the fusion and elimination of some bones and the pneumatization of the remaining ones. The extensive skeletal pneumaticity in theropods such as Majungasaurus demonstrates that a complex air-sac system and birdlike respiration evolved in birds’ theropod ancestors. The increased metabolism associated with homeothermy and powered flight requires an efficient gas exchange process during pulmonary ventilation. In addition, recent anatomical and physiological studies show that alligators and monitor lizards have respiratory systems and unidirectional breathing similar to those of birds, suggesting that unidirectional breathing is a primitive feature of archosaurs or an even broader group with the complex air-sac system evolving later within archosauria.
In later editions of The Origin of Species, Darwin mentions the Archaeopteryx: “That strange bird, Archaeopteryx, with a long lizardlike tail, bearing a pair of feathers on each joint, and with its wings furnished with two free claws . . . Hardly any recent discovery shows more forcibly than this, how little we as yet know of the former inhabitants of the world.” Today, with more than 10500 living species, birds are the most species-rich class of tetrapod vertebrates.
Xu, X., Zhou, Z., Dudley, R., Mackem, S., Chuong, C. M., Erickson, G. M., & Varricchio, D. J. (2014). An integrative approach to understanding bird origins. Science, 346(6215), 1253293.
Allen, V., Bates, K. T., Li, Z., & Hutchinson, J. R. (2013). Linking the evolution of body shape and locomotor biomechanics in bird-line archosaurs. Nature, 497(7447), 104-107.
MEYER v., H. (1861): Archaeopterix lithographica (Vogel-Feder) und Pterodactylus von Solenhofen. Neues Jahrbuch fur Mineralogie, Geognosie, Geologie und Petrefakten-Kunde. 6: 678-679
Letters from Gondwana. 