Friday 30 August 2013

Richard Owen (1804-1892): The Father of Dinosaurs

Richard-owen2.jpg

Richard Owen is one of the most important figures in the history of dinosaur research, primarily because he coined the term "dinosaur" and realised they were not just big lizards as previously believed but an entirely new group of reptiles. But despite this, he was not a very popular man amongst his colleagues. Let's take a closer look.


Owen was born on 20 July 1804 in Lancaster. He had five siblings. His father, also named Richard, was a merchant based in the West Indies. His mother, Catherine Parrin, was a Hughenot (a French protestant). Owen went to Lancaster Royal Grammar School (which today is a specialist Technology and Language college). He became an apprentice to a local surgeon and apothecary in 1820 where he gained sufficient medical knowledge to enrol as a medical student at Edinburgh University in 1824. The following year, he left the university to complete his medical training at St. Bartholomew's Hospital, London, where he was greatly influenced by the surgeon John Abernethy (nicknamed "Dr. My-Book" because of the number of times he referred to his book when dealing with patients).
 In July 1835, Richard married Caroline Clift in St. Pancras and the couple had one son, William. After he had completed his education, Owen intended to pursue anatomical research. However, Abernethy persuaded Owen to become the assistant to William Clift, the conservator of the Royal College of Surgeons. In this way, Owen changed his mind, and instead chose to become a scientific researcher. His first endeavour was to produce a catalogue of the specimens in the Hunterian Collection in the Royal College of Surgeons. This gave him the knowledge and experience necessary for him to become one the greatest biologists of his time.


Owen became a professor in 1836 and subsequently, in 1849, succeeded Clift as conservator. He remained in this position until 1856 when he became superintendent of the natural history collection of the British Museum. It was here that he made his greatest contribution to science, as he campaigned long and hard for the collection to be moved to a new building. This was eventually achieved in 1883 when the Natural History Museum in South Kensington, London was built. In reward for this accomplishment, Owen received a knighthood. Unfortunately, throughout his career, Owen was often accused of not properly acknowledging others for their work or taking credit for others' discoveries. This was most apparent in 1846 when he wrote a paper on belemnites (fossil molluscs similar to squid) but did not give credit to Chaning Pearce who had already described belemnites in 1842. As a result of this, Owen was struck off the councils of the Royal Society and the Zoological Society.

(Nautilus pompilius (Linnaeus, 1758))

Whilst Owen was busy describing the specimens in the Hunterian collection, he also dissected and described specimens that had recently died at London Zoo. His first major paper, and the one that brought him attention from other scientists, was his Memoir on the Pearly Nautilus (Owen, 1832). Amongst his other contributions to invertebrate science was his description of the Venus' Flower-Basket Sponge, Euplectella aspergillum (Owen, 1841), the roundworm Trichinella spiralis (Owen, 1835), he gave the Ram's Horn Squid (Spirula spirula, (Linnaeus, 1758)) its own family Spirulidae (Owen, 1836) and he described the oldest fossil footprints Protichnites (Owen, 1852) which he believed were produced by an animal similar to a horseshoe crab.

File:Iguanodon Crystal Palace.jpg

Despite his advances in invertebrate research, it was through studying vertebrates that Owen really excelled. His book Comparative Anatomy and Physiology of Vertebrates, published in three volumes between 1866 and 1868, served as the most authoritative source of anatomical information for vertebrates in the late 19th century. He also wrote extensively on teeth, culminating in the book Odontography in 1840. His greatest contribution to fish was his description of the African Lungfish genus Protopterus (Owen, 1839a).
 For the reptiles, Owen wrote a series of books entitled History of British Fossil Reptiles, published in four volumes between 1849 and 1884. His best-known contribution was his description of Dinosauria (Owen, 1842) which he based on three known dinosaurs: Megalosaurus (Buckland, 1824), Iguanodon (Mantell, 1825) and Hylaeosaurus (Mantell, 1833). Other fossil dinosaurs were known but they were believed to be large lizards or crocodiles and were not recognised as dinosaurs until much later. He also discovered a group of fossil reptiles that had similarities with both reptiles and mammals which he named Anomodontia (Owen, 1859a) which started with his description of Dicynodon (Owen, 1845). 
 For birds, he wrote papers on kiwis, dodos and other flightless birds, but his best known paper was one on Archaeopteryx (Meyer, 1861) in 1863 (Owen, 1863). 
 But perhaps Owen's greatest contribution to vertebrate research is his collaboration with Benjamin Waterhouse Hawkins with whom he constructed the prehistoric models in the Crystal Palace Gardens, which can still be seen today.

(Owen's depiction of a camel)

Finally, we arrive at his mammalian contributions. Firstly, he split the hoofed mammals into two orders: Artiodactyla (Owen, 1848) and Perissodactyla (Owen, 1848). Artiodactyla contains the even-toed hoofed mammals such as cattle, sheep, goats, deer, giraffes, pigs and hippopotamus. Perissodactyla contains the odd-toed hoofed mammals such as horses, tapirs and rhinoceros. Charles Darwin, whom Owen would have a rocky relationship with due to his theory of Evolution, collected a series of fossils of large hoofed mammal from South America which Owen described as Toxodon (Owen, 1837). Toxodon defied every attempt to classify it because it had similarties with hoofed mammals, rodents and whales, lending credence to Darwin's ideas. Owen continued to study the strange South American fossil mammals and described the giant armadillo Glyptodon (Owen, 1839b) and the giant ground sloth Mylodon (Owen, 1840). 
 Meanwhile, another explorer, Sir Thomas Mitchell, donated some giant fossil bones he had found in Australia to Owen. From these, Owen described Diprotodon (Owen, 1838), a giant wombat and Thylacoleo (Owen, 1859b) a carnivorous marsupial.

(Owen with a moa skeleton)

Now we come to the darker side of Owen. Owen had many feuds with many other scientists, most of which were vicious. His best known rivalry was with Charles Darwin who proposed the Theory of Evolution through Natural Selection. Owen initially believed that while species were effectively unchangeable and fixed, God modified pre-existing forms to produce new species. This is why animals look similar to each other. However, by the 1840s, Owen had changed his mind and came to believe that species arose from an evolutionary process as evidenced by his claim in 1849 that humans ultimately descended from fish (Richards, 1987). For this, he was heavily criticised and ridiculed and this likely stopped him from elaborating on his theories in his later career. However, he strongly disagreed with Darwin about man descending from apes. Owen went to great lengths to prove that humans could not have evolved from apes such as suggesting that apes lacked certain structures in their brain and their brains were far too small (Cosans, 2009).
 In response, Thomas Huxley (nicknamed Darwin's bulldog because of his aggressive defence of Darwin's theories) argued that a gorilla's brain is as similar to a baboon's as it is to a human's. Owen largely kept quiet in the face of this criticism...publicly that is. In 1860, Owen published an anonymous review of Darwin's On the Origin of Species (Owen, 1860). In it, Owen not only ridiculed and criticised Darwin's ideas, he also labelled Huxley and Joseph Hooker as short-sighted for defending Darwin so vigorously and even went so far as to say that On the Origin of Species symbolised an "abuse of science... to which a neighbouring nation, some seventy years since, owed its temporary degradation" referring to the French Revolution. In other words, if science accepts Darwin's theories, society will descend into the same chaos and anarchy as France seventy years earlier. Pretty dramatic.
 Huxley countered by presenting public dissections of various apes and visibly demonstrating the structures that Owen said didn't exist. Owen responded by admitting that there may be unique individuals with very poorly developed brain structures but ape brains are still far too small to be the ancestors of humans. Then it turned uglier. Huxley countered that due to "racial differences", man's brain size varies considerably with European man having larger brains and African man having smaller, ape-like brains (Huxley, 1861). Owen, however, downplayed these differences, remarking that brain size does not differ dramatically across the races. Owen and Huxley continued to fight for the rest of their lives. The scientific community largely sided with Darwin and Huxley. But Owen's anti-Darwinist views weren't the only reason why he was unpopular.
 As well as Darwin and Huxley, Owen had a lengthy feud with Gideon Mantell, in particular about the discovery of Iguanodon. Owen credited himself and Georges Cuvier with Iguanodon. When the scientific community sided with Mantell (Cuvier didn't really care much who received the credit), Owen became bitter. When he was president of the Royal Society, he used his influence to prevent many of Mantell's papers from being published. When Mantell suffered his horrible carriage accident that left him crippled and addicted to painkillers, Owen attempted to re-name many of Mantell's dinosaurs and even tried to claim he discovered them and not Mantell. His personal animosity towards Mantell and his previously mentioned Belemnite scandal with Pearce caused him to be removed from many academic institutions.

 After the British Museum of Natural History had been built and the collections transferred in 1883, Owen retired from academics and lived out the rest of his life at Sheen Cottage in Richmond Park until his death in 1892. Sheen Cottage was destroyed by German bombs in 1944 but the remains of the outer walls can still be seen.

The next biography will look at another controversial palaeontologist with a famous rivalry, the American Edward Drinker Cope. The next post, however, will look at another frequently asked question: How long did dinosaurs live for?

See also:
More dinosaurs
What is a dinosaur?
Gideon Mantell

References
Buckland, W. (1824) 'Notice on the Megalosaurus or great Fossil Lizard of Stonesfield', Transactions of the Geological Society of London, 2 (1), pp. 390-396

Cosans, C. (2009) Owen's Ape & Darwin's BulldogBeyond Darwinism and Creationism, Bloomington: Indiana University Press

Huxley, T. (1861) 'On the Zoological Relations of Man with the Lower Animals', Natural History Review, 1, pp. 67-84

Mantell, G. (1825) 'Notice on the Iguanodon, a newly discovered fossil reptile, from the sandstone of Tilgate forest, in Sussex', Philosophical Transactions of the Royal Society, 115, pp. 179-186

Mantell, G. (1833) The Geology of the South-East of England, London: Longman Ltd

Meyer, H. von (1861) 'Archaeopteryx lithographica (Vogel-Feder) und Pterodactylus von Solenhofen' Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefakten-Kunde, pp. 678-679

Richards, E. (1987) 'A Question of Property Rights: Richard Owen's Evolutionism Reassessed', British Journal of the History of Science, 20, pp. 129-171

Owen, R. (1832) Memoir on the Pearly Nautilus (Nautilus pompilius, Linné). With illustrations of its external and internal structure, London: R. Taylor

Owen, R. (1835) 'Description of a microscopic entozoon infesting the muscles of the human body', Transactions of the Zoological Society of London, 1 (4), pp. 315-324

Owen, R. (1836) 'Descriptions of some new or rare Cephalopoda, collected by Mr. George Bennett, Corr. Memb. Z. S.', Proceedings of the Zoological Society of London, 37, pp. 19-24

Owen, R. (1837) 'A description of the Cranium of the Toxodon Platensis, a gigantic extinct mammiferous species, referrible by its dentition to the Rodentia, but with affinities to the Pachydermata and the Herbivorous Cetacea', Proceedings of the Geological Society of London, 2, pp. 541-542

Owen, R. (1838) 'Fossil remains from Wellington Valley, Australia. Marsupialia' in Mitchell, T. (Ed) Three Expeditions into the Interior of Eastern Australia, with Descriptions of the Recently Explored Region of Australia Felix, and of the Present Colony of New South Wales, London: T. and W. Boone

Owen, R. (1839a) 'On a new species of the genus Lepidosiren of Fitzinger and Natterer', Proceedings of the Zoological Society of London, 1, pp. 327-361

Owen, R. (1839b) 'Description of a tooth and part of the skeleton of the Glyptodon, a large quadruped of the edentate order, to which belongs the tessellated bony armour figured by Mr. CLIFT in his memoir on the remains of the Megatherium, brought to England by Sir WOODBINE PARISH, F.G.S.', Proceedings of the Geological Society of London, 3, pp. 108-113

Owen, R. (1840) 'Description of a mutilated lower jaw and teeth, on which is founded a subgenus of megatherioid edentata, under the name of Mylodon', The Zoology of the Voyage of H.M.S. Beagle, under the command of Captain Fitzroy, R.N., during the years 1832 to 1836, pp. 63-73

Owen, R. (1841) 'On a new genus and species of sponge (Euplectella aspergillum)', Transactions of the Zoological Society of London, 3 (2), pp. 203-206

Owen, R. (1842) Report of British Fossil Reptiles Part II, London: John Murray

Owen, R. (1845) 'Report on the Reptilian Fossils of South Africa - Part I: Description of certain Fossil Crania, discovered by A. G. Bain, Esq., in Sandstone Rocks at the South-eastern extremity of Africa, referable to different species of an Extinct genus of Reptilia (Dicynodon), and indicative of a new Tribe or Sub-order of Sauria', Transactions of the Geological Society of London, 2 (7), pp. 59-84

Owen, R. (1848) 'Description of teeth and portions of jaws of two extinct anthracotherioid quadrupeds (Hyopotamus vectianus and Hyop. bovinus) discovered by the Marchioness of Hastings in the Eocene deposits on the N.W. coast of the Isle of Wight: with an attempt to develop Cuvier's idea of the classification of pachyderms by the number of their toes', Quarterly Journal of the Geological Society of London, 4, pp. 103-141

Owen, R. (1852) 'Description of the impressions and footprints of the Protichnites from the Potsdam sandstone of Canada' Geological Society of London Quarterly Journal, 8, pp. 214-225

Owen, R. (1859a) 'On the orders of fossil and recent Reptilia, and their distribution in time', Report of the British Association for the Advancement of Science, 29 (1), pp. 153-166

Owen, R. (1859b) 'On the fossil mammals of Australia. Part II. Description of a mutilated skull of the large marsupial carnivore (Thylacoleo carnifex Owen), from a calcareous conglomerate stratum, eighty miles S. W. of Melbourne, Victoria', Philosophical Transactions of the Royal Society, 149, pp. 309-322

Owen, R. (1860) 'Darwin on the Origin of Species', Edinburgh Review, 3, pp. 487-532

Owen, R. (1863) 'On the Archaeopteryx of Von Meyer, with a description of the fossil remains of a long-tailed species from the lithographic stone of Solnhofen' Philosophical Transactions of the Royal Society, 153, pp. 33-47

Linnaeus, C. (1758) Systema naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonomis, locis (10th Edition), Stockholm: Laurentius Salvius

Friday 16 August 2013

Discovering a dinosaur


Discovering a fossil is a wonderful experience and palaeontologists become really excited when they go on a fossil-hunting expedition (which doesn't happen that often - usually they stay at home, in a stuffy lab, studying fossils that are kept in the storage room of a museum). And their expeditions normally start when a member of the public finds an unusual specimen and alerts the experts. But before you go gallivanting across the countryside attempting to find the "next big thing", you need to know what it is you are looking for.


As can be seen in the above picture, there are usually large teams involved in digging up a dinosaur. This is because there is A LOT of work that needs to be done. You need people to dig large amounts of earth and rock (sometimes done with a machine if the fossil is deep enough), others need to remove small amounts of rock surrounding the fossil. You need a photographer to take pictures of the fossil and the surrounding area so researchers have a better idea of the rocks and the orientation of the fossil. And you need people to prepare the specimens for transport - this normally involves coating bones in plaster of paris and labelling them. In short, this isn't for people who prefer to work alone. You need people who know what they're doing.

(Grand Canyon, Arizona)

So, let's just say you are a palaeontologist and someone has presented you with a very impressive fossil. You have recruited all the relevant team members and you have arrived at the site. What's next? You need to know which rocks are more likely to harbour fossils than others. The best rocks for that are sedimentary rocks such as sandstones, mudstones, shales and limestones. Sometimes metamorphic rocks (rocks that have been shaped by intense heat and pressure such as slate) can contain fossils but they are often very distorted. Cliffs are really good places and it helps if they're by the sea because the water and wind will erode the outer layers of rock and expose the fossils underneath. This is why palaeontologists get really excited about a rockslide on the beach.


Unfortunately, many of the locations where fossils are found are very dangerous. As mentioned, they are normally found in areas prone to landslides and other effects of erosion and weathering. And though I've never tried it, I'm pretty sure the human body does like being thrown off steep cliffs. There is also an additional danger. Sometimes the land that fossils are found in are private and most people don't appreciate trespassers, especially if they are digging large holes everywhere. So remember, stay safe and always ask permission before you do anything. 

So they are my tips: gather a large team, look for sedimentary rocks, stay away from danger and obtain permission from any landowners. Next time, we'll look at what happens to the fossils when they get back to the museum or lab. In the next post, we'll look further into the man that gave us dinosaurs: Richard Owen

Monday 5 August 2013

Heads up!


Dinosaurs are strange looking things aren't they? They resemble nothing that exists today. However, if we look closer, we can spot some similarities between them and living animals. In this post, we'll take a look a their skulls - what do they tell us about how dinosaurs lived?


First up is Prenocephale (Preen-o-sef-a-lee) (Sloped Head) (Maryanska and Osmolska, 1974). As can be seen in the picture, Prenocephale possesses a domed head. The function of the dome is a matter of much debate with ideas ranging from competition between males for mating (Colbert, 1955) to species or individual recognition (Goodwin and Horner, 2004).


Next is Troodon (Tro-o-don) (Wounding Tooth) (Leidy, 1856). The narrow, delicate jaw it possesses would indicate it is a carnivore. It has large, forward-facing eyes that helped it to gauge distances when hunting for prey. It's teeth, however, tells a more complicated story. To keep it short, there are two opposing views. That of Holtz et al. (1998), who believe Troodon to be omnivorous (based on the size and spacing of its denticles (small serrations on the tooth itself)) and Fiorillo (2008), who believes them to be entirely carnivorous (based on the large size of the teeth and their wear patterns). Now, you may have heard that Troodon is the most intelligent dinosaur based on its brain-to-body size ratio. We'll be looking at this claim in more detail later.


Next is Euoplocephalus (Yoo-Op-Low-Seff-A-Lus) (Well Armoured Head) (Lambe, 1910). Euoplocephalus has a wedge-shaped, squat head protected by spikes. It also has a short, wide mouth similar to a rhinoceros' with which it ate low-growing plants and shrubs. It's skull is very distinctive when compared to other ankylosaurs with relatively small, variably fluted teeth that lack a cingulum (a ridge at the base of the tooth), modified palpebrals (eyelids), shallow nostrils and the teeth of the upper jaw are curved towards the middle (Vickaryous and Russell, 2003). It also possessed bony eyelids, however, these are no longer regarded as being unique to Euoplocephalus (Coombs, 1972). However, despite this slew of defining characteristics it has recently been suggested that what we know of as Euoplocephalus is actually composed of four different genera namely: Euoplocephalus, Anodontosaurus (An-Oh-Dont-Oh-Saw-Us) (Toothless Lizard) (Sternberg, 1929), Scolosaurus (Sko-Low-Saw-Us) (Pointed Stake Lizard) (Nopcsa, 1928) and Dyoplosaurus (Die-Op-Low-Saw-Us) (Doubly-Armoured Lizard) (Parks, 1924). If this is the case, the distinguishing features of Euoplocephalus would become: absence of any ornamentation behind the eyes and, on the first armour ring of the neck, again no ornamentation and the osteoderms (bony scales) in the middle have a keel (in biology, ornamention is anything that serves as a display feature like spikes, horns, brightly-coloured feathers etc.) (Arbour and Currie, 2013). But we'll look in more detail on that later.


Finally, we have Styracosaurus (Stye-Rack-Oh-Saw-Us) (Spiked Lizard) (Lambe, 1913). Pretty impressive skull isn't it? There is a lot of variation amongst Styracosaurus individuals but they all seem to have had at least four large spikes on the frill. These spines could reach 50-55 cm long (Dodson, 1996). The large nasal horn, however, is probably not as big as depicted in this picture. The original specimen that Lambe used to described Styracosaurus had an incomplete horn. Lambe estimated that this horn was about 57 cm long. However, based on other material discovered since, the horn probably probably ended in a rounded tip about 20 cm long (Ryan et al., 2007). The function of the frill and horns has been debated about for decades. The ideas have been: attachment points for large jaw muscles (Lull, 1908); combat/defence (Farke et al., 2009); to regulate body temperature in a similar fashion to elephant's ears (Wheeler, 1978); and for sexual display (Farlow and Dodson, 1975).

So, as can be seen, dinosaur skulls are very varied and can provide us with a lot of information, even if there are still many unanswered questions. Next time, we'll take a look at another four dinosaur skulls. However, for the next post, we'll look at the process palaeontologists take to find, excavate and study fossils, starting with where they look for fossils.

See also:
More dinosaurs
More dinosaur anatomy
Even more dinosaur anatomy

References
Arbour, V. and Currie, P. (2013) 'Euoplocephalus tutus and the Diversity of Ankylosaurid Dinosaurs in the Late Cretaceous of Alberta, Canada, and Montana, USA', PLoS Onehttp://www.plosone.org/article/info:doi/10.1371/journal.pone.0062421

Colbert, E. (1955) Evolution of the Vertebrates, New York: John Wiley

Coombs, W. (1972) 'The Bony Eyelid of Euoplocephalus (Reptilia, Ornithischia)', Journal of Paleontology, 46 (5), pp. 637-650

Dodson, P. (1996) The Horned Dinosaurs: A Natural History, Princeton: Princeton University Press

Farke, A., Wolf, E., Tanke, D. and Sereno, P. (2009) 'Evidence of combat in Triceratops', PLoS Onehttp://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0004252

Farlow, J. and Dodson, P. (1975) 'The behavioral significance of frill and horn morphology in ceratopsian dinosaurs', Evolution, 29 (2), pp. 353-361

Fiorillo, A. (2008) 'On the Occurrence of Exceptionally Large Teeth of Troodon (Dinosauria: Saurischia) from the Late Cretaceous of Northern Alaska', Palaios, 23 (5), pp. 322-328

Goodwin, M. and Horner, J. (2004) 'Cranial histology of pachycephalosaurs (Ornithischia: Marginocephalia) reveals transitory structures inconsistent with head-butting behavior', Paleobiology, 30 (2), pp. 253-267

Holtz, T., Brinkman, D. and Chandler, C. (1998) 'Denticle morphometrics and a possibly omnivorous feeding habit for the theropod dinosaur Troodon', Gaia, 15, pp. 159-166

Lambe, L. (1910) 'Note on the parietal crest of Centrosaurus apertus, and a proprosed new generic name for Stereocephalus tutus' Ottawa Naturalist, 24, pp. 149-151

Lambe, L. (1913) 'A new genus and species of Ceratopsia from the Belly River Formation of Alberta', Ottawa Naturalist, 27, pp. 109-116

Leidy, J. (1856) 'Notice of remains of extinct reptiles and fishes, discovered by Dr. F. V. Hayden in the badlands of the Judith River, Nebraska Territory', Proceedings of the Academy of Natural Sciences of Philadelphia, 8, pp. 72-73

Lull, R. (1908) 'The cranial musculature and the origin of the frill in the ceratopsian dinosaurs', American Journal of Science, 4 (25), pp. 387-399

Maryanska, T. and Osmolska, H. (1974) 'Pachycephalosauria, a new sub-order of ornithischian dinosaurs', Paleontologia Polonica, 30 (3), pp. 45-102

Nopcsa, F. (1928) 'Dinosaurierreste aus Siebenbuergen' Geological Hungarica Series Palaeontologica, 4, pp. 1-76

Parks, W. (1924) 'Dyoplosaurus acutosquameus, a new genus and species of armored dinosaur; with notes on a skeleton of Prosaurolophus maximus', University of Toronto Studies Geological Series, 18, pp. 1-35

Ryan, M., Holmes, R. and Russell, A. (2007) 'A revision of the late Campanian centrosaurine ceratopsid genus Styracosaurus from the Western Interior of North America', Journal of Vertebrate Paleontology, 27 (4), pp. 944-962

Sternberg, C. (1929) 'A toothless armored dinosaur from the Upper Cretaceous of Alberta', Bulletin of the National Museum of Canada, 54 (49), pp. 28-33

Vickaryous, M. and Russell, A. (2003) 'A redescription of the skull of Euoplocephalus tutus (Archosauria: Ornithischia): a foundation for comparative and systematic studies of ankylosaurian dinosaurs', Zoological Journal of the Linnean Society, 137 (1), pp. 157-186

Wheeler, P. (1978) 'Elaborate CNS cooling structures in large dinosaurs' Nature, 275 (5679), pp. 441-443