Long living pets that could go along with their owners for years have always been an attraction, as one can see by the popularity of turtles as pets, as well as psittacids, which are also vivid and interactive. Animals tend to live longer in captivity, not being exposed to the dangers of the “wild”. Some, however, exceed the expectations concerning longevity and become very curious characters. One of those was a cockatoo that lived more than a century in Australia, between the 18^th and 20^th centuries.

Called Cocky Bennet, a sulphur-crested cockatoo (Cacatua galerita), he stood out not by the age he would reach, but for its unusual physical features. Born in 1796 (according to Brisbane’s weekly summary, The Queenslander), near Sydney, he was removed from his nest on a eucalypt by a local farmer. As the years passed, he started to lose the feathers, looking like a plucked chicken with a wrinkled skin. Moreover, his upper mandible had an extraordinary long tip, so that he could only eat mashed food. Such abnormalities are typical of the psittacine beak and feather disease, caused by a circovirid virus, which also lowers the animal’s immunity against the effects of other viruses and bacteria.

Cocky Bennet with an age of 115 in his cage, 1911. Photo from the archive of State Library of Victoria, Australia.

The bird spent his first 78 years travelling the world with Captain Ellis, his owner. Following the death of the captain, he was bequeathed to a Mr. and Mrs. Bowden. With the death of Mr. Bownden in 1889, his wife soon married Charles Bennet, with the couple then moving to Tom Ugly’s Point, Blakehurst, in 1891, where Mr. Bennet became the licensee of the Sea Breeze Hotel.

Popular, Cocky lived in the hotel for most of his last 25 years. Talkative, his repertory included phrases like “one feather more and I’ll fly” and “one at a time, gentlemen, please”, when harassed by other birds. Cocky was more talkative and with more lurid language after being given a ”sip of strong brew”.  He received the visitors while moving and jumbling at the top of his cage in the hotel’s front verandah.

Cocky Bennet with an age of 118, 1914. Photo from the archive of Sutherland Shire Libraries, Australia, used with permission.

Despite being affected by the disease, he passed away only in May 1916, being the longest living psittacid registered in Australia. As there are no sources indicating in which month Cocky was removed from his nest, it’s not possible to determine if he was already 120 years old or still 119. Sulphur-crested cockatoos, in Sydney, breed from August to January and the eggs hatch after about 25 days. So, assuming that he wasn’t a newborn (for he possibly wouldn’t have survived if removed from the nest as soon as he left the egg), the farmer probably took him between about late September and late February. Back in the day, his age was estabilished by ornithologists counting the growth rings of his beak, concluding he was 120 years old, give or tak a year. The mean lifespan for his species is 70 years.

Cocky Bennet, 1914. Photo from the archive of Sutherland Shire Libraries, Australia, used with permission.

After his death, The Sydney Morning Herald published (in 1916) the following note:

A Venerable Cockatoo

“Cocky Bennet,” a sulphur-crested Australian cockatoo, died on Friday in his 120^th year at Canterbury. This age is a record in longevity for an Australian parrot so far as the officials records are concerned. For many years this bird was in the possession of Mrs. Sarah Bennet, the licensee of the Sea Breeze Hotel, at Tom Ugly’s Point. When she left there, about 12 months ago, she transferred the parrot to her nephew, Mr. Murdoch Alexander Wagschall, at Woolpack Hotel, Canterbury. The old bird was absolutely featherless for the last 20 years, but it maintained its “patter” till the day before its death. “Cocky Bennet” was a great traveller, and is said to have journeyed seven times round the world. Mr. Wagschall has arranged to have remains of this historic parrot preserved by a taxidermist.”

Accordng to W. A. Easterling (The Sydney Morning Herald from July 9 1984), a distant nephew of Mrs. Bennet, the bird was stuffed and mounted by the firm Tost and Rohu and set in a glass case. It remained at the hotel until the late 1920s or early 1930s, when his grandmother, Mrs. P.Wagschall (whose husband operated the old Woolpack Hotel at Canterbury), left the hotel business. Then handed to his mother, Cocky hung in their dining room for more than 40 years, where it he became used for the family members but the visitor were unnerved by the baleful glare of the relic. His late wife once commented that she was in two minds about marrying him lest he inherit the old horror. After his family home was sold, his sister handed Cocky’s remains to the Kogarah Historical Society in their museum at Carss Cottage in Carss Bush Park, together with such documents that they had.

Easterling also notes that The Sutherland Council library held in May 1973 a feature display about the bird, and its researches brought forth much more historical information than was known to his part of the family. The matter was also thrased out in Column 8 (Herald, May 12, 1973), when the impostor specimen was displayed at the Sea Breeze Hotel, where he understand that it was acquired from a private museum at Kurnell and had been shown as Cocky’s alleged remains.

- – -

References:

Centre for Fortean Zoology Australia. 2011. From the archives: A Venerable Cockatoo (1916). Available on-line at: <www.cfzaustralia.com/2011/09/from-archives-venerable-cockatoo-1916.html>. Acess on February 13, 2012.

Grellis, A. 2008. Blakehurst: Cocky Bennet. Dictionary of Sydney. Available on-line at: <www.dictionaryofsydney.org/entry/blakehurst>. Acess on February 14, 2012.

About a week ago I went with my parents to my aunt’s house in the neighbor city, Estância Velha, and my parents decided to go to my uncle’s house, across the street, to fish at his property. I went along, but since it was too hot to stay still in the sun with a fishing rod, I decided to go for a walk through the grassfield to find interesting things to photograph.

At first, when one looks at a grassfield, it looks like an endless amount of grass and nothing else, but if you look closer you can find an amazing diversity of flowering plants living there.

Here I will present the beautiful flowers I found there after only about one hour exploring the field.

Sida rhombifolia L.

Ludwigia tomentosa (Cambess.) H.Hara

Ludwigia peploides (Kunth) P.H.Raven

Elephantopus mollis Kunth

Tibouchina cf. gracilis (Bonpl.) Cogn.

Tibouchina herbacea (DC.) Cogn.

Leandra regnellii (Triana) Cogn.

Solanum cf. atropurpureum L.

Commelina erecta L.

Tripogandra diuretica (Mart.) Handlos

Begonia cucullata Will.

Desmodium incanum DC.

Asclepias curassavica L.

Sisyrinchium micranthum Cav.

Richardia brasiliensis Gomes

And there are also some that I wasn’t able to identify. If someone knows their names and could help me with the identification, I would be very thankful. And please, let me know If I misidentified any species. Here are the ones awaiting identification:

Unidentified

Asteraceae

Asteraceae (?)

Liliaceae (?)

Fabaceae

Lamiaceae (?)

All photos by Piter Kehoma Boll.

by Piter Kehoma Boll

What would you think if someone came to you and said that your pet snail accidentally got pregnant and you’re the father? Or if you went to the doctor and he said to you “congratulations, you’re pregnant and the father is a sea urchin”. Of course you’d be proud, dontcha?

Well, if you think that’s a ridiculous nonsense, you’re quite right. But guess what? There’s a senior (i.e., very old) scientist claiming that such a thing happens in nature all the time! And what’s his name? Donald I. Williamson.

Donald I. Williamson. I found this photo (the only one) on a Polish blog (biokompost at wordpress.com). Unfortunately I don't speak Polish... yet.

Born in 1922 (he’s 90!), he’s a British planktologist and carcinologist, already retired, of course. But at least from 1987 on he has been publishing a series of weird papers claiming that hybrids between different animal phyla happened many times during the history of animal kingdom.

All started, as already mentioned, in 1987, on his paper “Incongruous Larvae and the Origin of some Invertebrate Life-Histories” where he considers the huge differences between adults and larvae in many animals, at first mainly concerning echinoderms. His “revolutionary” idea is that larvae and adults evolved separately as different lineages of animals and later became a single species by hybridization. He claims it by initially citing works that suggest the possibility of horizontal gene transference between distantly related organisms, mainly caused by viruses carrying a small amount of their hosts’ DNA from one to another. So he apparently thought “If one can carry one gene from an animal to another, why couldn’t it happen with the whole genome?”.

Echinoderms, his first victims, are thought to have hybridized with hemichordates, so explaining why the larvae of both groups are so similar. By the end, he admits that he hasn’t made any research concerning all or most of the recent works on development and phylogeny of the targeted groups.

A starfish (Echinoderma) and an acorn worm (Hemichordata). Surely a lovely couple. Photos by Mike Murphy and Philcha, from Wikipedia.

Here is important to cite a work by Švácha (1992) studying the imaginal disks in larvae of holometabolous insects (those with larva, pupa and adult stages). Imaginal discs are some regions of apparently undifferentiated cells in insects larvae and previously thought to be the source of most of the adult features not found in larvae, as well as being responsible for the replacement of some organs in larvae by new ones in adults, like the larvae’s antennae being replaced by new ones during the transition from one stage to another. Švácha noticed, however, that this actually doesn’t happen and that imaginal discs only help to develop larvae’s structures, but not replace them by new ones. That is to say, the adult form of insects does not come from a second “embryo” hidden inside the larva.

Of course Williamson ignored this paper and many others and in 2001 he brought another argument to sustain himself: a fallacy.

As you might or not know, the endosymbiosis theory suggests that some intracellular organelles, like mitochondria and chloroplasts, originated from bacteria associated to eukaryote cells. One then can state that the functions of intracellular organelles existed before the organelles themselves, so it was completely logical for Williamson to assume that the features of larvae existed before animals having larvae.”

Like if he was in a frenetic state, Williamson started to discharge loads of “perfectly possible” hybridizations between animal groups. To cite some:

• Turbellarian larvae came from Rotiferans

A polyclad (Turbellaria) and a 'wheel animal' (Rotifera). Another lovely couple. Photos by Dr. James P. McVey from the NOAA Sea Grant Program; and Absolutecaliber, from Wikipedia.

• Echinoderm larvae came from Hemichordates
• Tunicate larva came from Appendiculata (an old group comprising Arthropods, Annelids, Rotifers and others)

And to be even more bizarre, he suggests that the blastula in animals’ embryos came from hybridization with Volvocales, a group of green algae!

Acoording to Williamson (2001), the blastula of animals embryo came from hybridization with an algae of group Volvocales (left). Photos by the Environmental Protection Agency, US Federal Government; and Pearson Scott Foresman, from Pearson Company.

And as you can also see by reading his work, most of his references are his own previous works, obviously indicating a lack of interest in any REAL study trying to understand the origin of differences between larvae and adults. It is also worth noting that Williamson had some unusual phobia for the names of echinoderm classes, since the ending –oidea was to annoying for him to be seen in something other than a superfamily.

By 2006, Minelli et al. presented an interesting review of researches concerning the development of arthropods from larval forms to adults, where one of the possible explanations to the drastic change occurring in holometabolous insects larvae is nothing more complex that a kind of “neoteny”, i.e., when earlier stages of development last longer in an organism’s life cycle. In this case, the probable thing that happens is that the larva of holometabolous insects are kind of very developed and mobile embryos, nothing that weird, right? And guess what? In the whole review there is not even a single mention to Williamson, and we all can imagine why…

In this same year, Williamson attacks again with another paper, this time claiming that the Cambrian explosion happened due to a high number of hybridizations with larval transfer and, as in all of his previous works, uses the argument that “natural selection cannot explain such divergences between adults and larvae”. We can clearly notice that he completely ignores all recent publications concerning phylogenetics and genomics and, as it at least seems to me, ignores anything related to evolutionary theories other than Darwin’s The Origin of Species and Lynn Margulis works (to whom he appears to have some desperate passionate feelings).

An then again, in 2009, he comes with another article, this one at PNAS, entitled “Caterpillars evolved from onychophorans by hybridogenesis” where he persists in his absurd ideas, claiming that caterpillars arouse from a female moth being accidentally fertilized by a male onychophoran. and he still goes on ignoring anything related to molecular data, attacking Darwin’s and Haeckel’s ideas once more and citing only works that, by his limited point of view, could support in any way his incongruent ideas. All works published during these more than 20 years that he passed affirming the same nonsense, like a fanatic priest in a church, were left aside.

"Excuse me, Ma'am, but you just got fecundated by my semen". The two original parents of a caterpillar, according to Williamson, would have been a welvet worm (Onychophora) and a moth (Insecta). Photos by Thomas Stromberg and Jonathon Coombes.

Anyway, this last work gained a higher repercussion than the previous ones and many scientists manifested their indignation with it, so that for two months the paper was held up from print publication, until finally appearing in print in the issue of November that year.

Now, seriously, how could it be possible that such a ridiculous idea was allowed to be published in this century, after all the serious researchers concerning phylogeny and ontogeny of animals?

Well, it was possible only for one reason: Lynn Margulis. She was the one that communicated the paper, via a submission route that allowed  academy members of the United States National Academy of Sciences to manage the peer review of a colleague’s manuscript. But why would Lynn Margulis support such an idea from an old retired out of his mind “scientist”? I should say because she was pretty out of her mind too.

Lynn Margulis, photo by Javier Pedreira.

If you know Lynn Margulis, you also know that she was once a brilliant biologist with challenging ideas, helping to make the endosymbiosis theory to get known and eventually accepted to explain the origin of chloroplasts and mitochondria. But in her last years (she died on November 22, 2011) she started to attack well supported ideas in science in a kind of irrational way, like stating that AIDS isn’t caused by HIV.

When this last work was released for press, the same issue brought a challenge by zoologist Gonzalo Giribet and a paper by Hart & Grosberg rejecting Williamson’s ideas based on all molecular data already available that clearly indicate that holometabolous insects do not have onychophoran genes at all to explain such a BS.

Apparently Williamson prepared a briefly response, but it was not released to be published.

So after reading all this, I think anybody can understand why nobody can take him serious. Or would you ever believe that you can get pregnant by a jellyfish while swimming in the sea?

- – -

References:

Abbott, A., Brumfiel, G., Dolgin, E., Hand, E., Sanderson, K., Van Noorden, R., & Wadman, M. 2009. Whatever happened to …? Nature DOI: 10.1038/news.2009.1162

Giribet, G. 2009. On velvet worms and caterpillars: Science, fiction, or science fiction? Proceedings of the National Academy of Sciences, 106 (47), e131 DOI: 10.1073\pnas.0910279106

Hart, M., & Grosberg, R. 2009. Caterpillars did not evolve from onychophorans by hybridogenesis Proceedings of the National Academy of Sciences, 106 (47), 19906-19909 DOI: 10.1073/pnas.0910229106

Minelli, A., Brena, C., Deflorian, G., Maruzzo, D., & Fusco, G. 2006. From embryo to adult—beyond the conventional periodization of arthropod development Development Genes and Evolution, 216 (7-8), 373-383 DOI: 10.1007/s00427-006-0075-6

Švácha, P. 1992. What Are and What Are Not imaginal Discs: Reevaluation of Some Basic Concepts (Insecta, Holometabola) Developmental Biology, 154, 101-117

Williamson, D. 1987. Incongruous larvae and the origin of some invertebrate life-histories Progress In Oceanography, 19 (2), 87-116 DOI: 10.1016/0079-6611(87)90005-X

Williamson, D. 2001. Larval transfer and the origins of larvae Zoological Journal of the Linnean Society, 131 (1), 111-122 DOI: 10.1006/zjls.2000.0252

Williamson, D. 2006. Hybridization in the evolution of animal form and life-cycle Zoological Journal of the Linnean Society, 148 (4), 585-602 DOI: 10.1111/j.1096-3642.2006.00236.x

Williamson, D. 2009. Caterpillars evolved from onychophorans by hybridogenesis Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0908357106

The first known image of a living Myanmar snub-nosed monkey, acquired by camera trap. Image on public domain, 2012.

We want to bring every month a post of this bulletin with natural history network itens that catch our attention. Every month we will write the article and along with it bring to light his view on things, such as news, related blog entries, reviews on books, artistry and so on.

News

• Dan Warner, notable paleoartist for marine enviroiments, dies in January 1 2012.
• Photos of living Myanmar snub-nosed monkeys, Rhinopithecus strykeri, a highly threatened species described in 2010.
• “Extinct” giant tortoise found, a giant Galápagos tortoise believed extinct for 150 years probably still exists, say scientists.
• “Extinct” monkey is rediscovered, Miller’s grizzled langur (Presbytis hosei canicrus) has been photographed in Wehea forest in eastern Borneo.
• Study fails to confirm existence of arsenic based life, a new analysis was not able to support the controversial study claiming that a species of bacterium could replace phosphorous by arsenic in its DNA.
• Male mice have “singing voices”, a study reveals that the pattern of voice in male house mice are more complex than expected.
• Prehistoric predator from Palaeozoic found in Brazil, Pampaphoneus biccai was a top predator and closely related to mammals.
• Burmese pythons are declining Everglade’s mammal populations at an astonishing rate, new surveys found out that the exotic pythons living in the Everglades are becoming a major threat to the survival of the native mammals, eating from rabbits to bobcats.
• Petrobras suffers oil leak at Brazil tanker terminal, the Brazilian state-controled oil company, Petrobras, suffered an oil spill at an offshore terminal in southern Brazil, which reached Tramandaí beach in Rio Grande do Sul State.
• New snake species discovered - Atheris matildae, a colorful horned viper is discovered in Tanzania, but its exact location remains secret to avoid illegal hunting for wildlife trade.
• Beyonce’s Fly Scapia (Plinthina) beyoncea, named after the pop singer. Yes, taxonomy uses to have some shocking ideas.

Blog

Posts on nature blogroll that catched our attention this month:

• Nature Blog Network post on newbies from January 18h, including us!
• “My, What Weird Teeth You Have!“, post on notosuchians by Jaime A. Headden at The Bite Stuff.
• “Rigid Swimmer” and the Cretaceous Ichthyosaur Revolution (part I)”, by Darren Naish at Tetrapod Zoology.
• “O RNA se acha o tal, mas não é a toa!” (RNA fancies itself, but it’s not for nothing!), by Natália Dörr at Tage des Glücks (in Portuguese).

Books

• The Blind Watchmaker, by Richard Dawkins. If you still haven’t quite understood how evolution could shape all lifeforms on our planet, you’ll be fascinated by how everything is so simple and perfectly possible after reading this great book by one of the most influent biologists of our time.

Art
Here are some pictures that came to light in this month and in my opinion deserve an place under the sun:

• “Carcharodontosaurus sanagasta” by Jorge Antonio Gonzalez – Gonzalez made this 10 meter long model of polyester resin with Ernesto Rodriguez, Cecilia and James Dellagiovanna, Sebastian Perez Parry and Maria de los Angeles Meza, with Gonzalez himself participating in sculpture and art direction. A great detailed model with eyes that don’t show the expression of monsters we usually see in those theropods. This is the main point that made me like it.
• “Ceratosaurus” by Sergey Krasovskiy  – high detailed picture in a superb traditional artwork. Krasovskiy pictures always present us incredible scenarios with accurate and dynamic animals.
• “Coelodonta nihowanensis” by Chen Yu - skull and reconstruction of this obscure rhinoceros from Early Pleistocene of China. Chen’s gallery on DeviantArt is full of amazing compositions featuring extinct mammals that usually are out of the focus of the sight of the  general reader.
• “Fisher King revisited” by Scott Hartman – Hartman’s technical drawings are, along with Gregoy Paul’s, a reference for most of the recent popular paleontological pictures we see in internet. A place he deserve, of course, with his pictures being product of deep research. This time, Spinosaurus aegypticus skeleton, which the original finds were destroyed by a bombardment during the World War II.
• “The Vicious Lizard of Madagascar” by Julio Lacerda - this composition make us think we are looking direct into a photograph of a long-gone creature. Lacerda’s pictures really catch my attention for being digital without looking ”plastic”, for being very accurate anatomically and making the dinosaurs looking the animals they were, not monsters. Yes, I really don’t like dinosaurs being depicted as creatures from hell with an insatiable thirsty for blood and destruction.
• “The Pampa Killer” by Jennifer Viegas – good to see a familiar name illustrating an article telling the world about the discovery of this Brazilian synapsid.
• “Singapore – Panorama IV” by Yousef Al Habshi – an amazing view of Singapore and the ocean behind, where you can also see the city sadly growing over the forest.

Scientific Articles

• A new threat to honeybees, the parasitic fly Apocephalus borealis: an interesting discovery of honeybees being parasitized by a species previously only known to affect bumblebees.
• New Ophthalmosaurid Ichthyosaurs from the European Lower Cretaceous Demonstrate Extensive Ichthyosaur Survival across the Jurassic–Cretaceous Boundary: this new discovery changes the view of how mass extinctions during Mesozoic affected ichthyosaurs. Apparently they weren’t that bad represented in Cretaceous as previously thought.
• The maximum rate of mammal evolution, measurements about evolution of body size in Mammals suggest that for a mouse to reach the size of an elephant, it would take about 24 million generations or 10 million years.
• Snake modulates constriction in response to prey’s heartbeat, constrictor snakes, or at least boas, seem to have the ability to measure prey’s heartbeat to control the amount of pressure applied.

This post is just a note about something I have been witnessing more frequently in my daily life. I use to wait for the bus at a terminal attached to a subways station in the south of the city. As a lover of animals, I always have my attention caught by any species occurring in this chaotic surrounding that makes a city, mainly birds, which are the class that concentrates most of my interest.

A rock pigeon that I photographed at the garden of Museu Paulista of University of São Paulo. I used to go there more often to see the birds.

During the day I use to see, near the place I work, kiskadees (Pitangus sulphuratus), rufous-bellied thrushes (Turdus rufiventris), rufous horneros (Furnarius rufus), plain parakeets (Brotogeris tirica), swallows, hummingbirds and, of course, pigeons (Columba livia) and sparrows (Passer domesticus). And those last two are the focus of this post. A bus terminal is a naturally crowded and busy place, even more if attached to a subway station. And at the time I return home, this crowd increases drastically. And a place with a high flow of people demands places to sell food. And a high flow of people and food means a filthy mess, and that attracts animals that feed on that mess, something quite predictable. It’s amazing how human beings, used to this automatic daily life where everything has to be quick, sometimes pass, without noticing, over the birds that feed on all this filth. Yes, they transmit diseases, but they are living beings after all. And blaming the animals for being there is ironic, since Man himself disseminated them from the Old World during his transcontinental comings and goings.

Well, returning to the focus: the animals ended up getting used and not being intimidated with the presence of humans, associating them to an easy source of food. However the birds don’t seem to get intimidated by the vehicles either, and that’s their biggest danger in places like that. Today I watched an old lady who wildly threw cheese breads to the pigeons. And since I was sitting next to her, a flock of them (thirteen birds, I counted them) was surrounding me. And this happened on a platform with several people in a hurry that eventually kick the pigeons and move their food to the street. And in the dispute between pigeons and even sparrows that don’t seem to fear the larger pigeons (which they eventually attack), the vehicles arrive and end up crushing an unaware bird that preferred to remain disputing a piece of snack rather than flying away to ensure a longer stay among the living ones. In the same day I saw a pigeon being crushed and another one having its tail trapped by the wheels of a bus (but this once escaped). Today I saw some daring sparrows carrying pieces of food almost as big as themselves to the cover of the platform, and a small chick that was cuddled in the middle of the street, bathed by the evening sun, until a bus came, whose second pair of wheels the sparrow wasn’t able to escape from. Even if they are considered plagues and that there’s a need to control their population to avoid the lack of hygiene and proliferation of diseases, it’s sad to witness in such a frequent way the death of those animals, which is the result of a poor planning and management of the environment created by men.

One of the big questions without an answer in our knowledge of the world is “How many species are there on the Earth?” and we are far from having even an approximation of the real number. There are, for sure, thousands of speculations, varying hugely between them, but we could say that a mean value would be about 10 million species, while we currently know only about 1.5 million. And that’s exactly the point I’m interested in focus here: the number of species we currently know. Are we sure that all we consider species are in fact so?

Probably everybody has already heard about a situation where a group of organisms once considered a single species where in fact two distinct ones, like the African elephants Loxodonta africana and L. cyclotis, where the latter was only classified as a distinct species by 2010.

African bush elephant, Loxodonta africana (left) and african forest elephant, Loxodonta cyclotis (right). Photos by Muhammad Mahdi Karim (left), from www.micro2macro.net, and Peter H. Wredge (right), extracted from Wikipedia.

As for people in general, if you ask them to say the name of an animal, they would probably tell the name of a mammal, or perhaps a bird, reptile or if you are lucky, they will say “butterfly” or “spider” and that’s all. Well, that’s nothing wrong with it, but I think people should realize that those animals, like lions or elephants, are just a small particle in the entire world of species.

I currently hold an undergraduate research at Unisinos (Universidade do Vale do Rio dos Sinos / University of the Sinos Valley), Brazil, working at the IPP (Instituto de Pesquisa de Planárias / Planarian Research Institute) with land planarians’ ecology, physiology and behavior.

For those who don’t know (and I know there are a lot of people who don’t), land planarians are terrestrial flatworms, belonging to the phylum Platyhelminthes, in the group Tricladida. They are usually found under rocks or logs in forested areas, but also in gardens or elsewhere. Many of them are very sensible to light, high temperatures or extremes of drought and moisture, so that their presence may indicate a more conserved area.

Two specimens of Luteostriata abundans (Graff, 1899), a land planarian from southern Brazil. Photo by Piter Kehoma Boll.

Geoplana rubidolineata Baptista & Leal-Zanchet, 2006. Photo by Fernando Carbayo, extracted from Baptista & Leal-Zanchet, 2006.

Land planarians are a group still poorly known and, despite a high number of species having been described in the last decades, many more are yet to be, and those already described are not well understood in what concerns their ecology and behavior.

The first described land planarians were defined based only on external features, mainly their body shape, color and eyes arrangement. But Ludwig von Graff, in his 1896 work “Über die Morphologie des Geschlechtsapparates der Landplanarien” (On the Morphology of the Reproductive Apparatus of Land Planarians) already noticed the importance of internal morphology, mainly that of the copulatory apparatus, for a more precise identification at the species level.

Sagittal reconstruction of the copulatory apparatus of Rhynchodemus scharffi Graff, 1896. Extracted from Graff, 1896.

Despite that, the following years were still marked by publications concerning only external features, like the work of Schirch (1929). Only by the 1950’s a real focus was started to be given in the structure of male and female organs. Most of the following works on land planarians’ descriptions, like those of the Marcus and Froehlich couples, focused on the copulatory apparatus together with external features, so giving a more trustful description of new species. By this moment, the reproductive structures became essential for the classification of new species and eventually led to the creation of new genera.

Drawing of several land planarian species. Extracted from Schirch, 1929.

Drawings of internal and external structure of several land planarians. Extracted from Marcus, 1951.

In 1990, Ogren and Kawakatsu published an index of all known species of land planarians in family Geoplanidae by that time. They noticed that many species still classified in the genus Geoplana, like those described by Schirch, were never reviewed and were still only known by external features, so that their position within Geoplana may not be correct. To avoid this misclassification, they created a new “temporary genus”, which they called Pseudogeoplana (false Geoplana) and put all those dubious species in it to stay there until someone reviewed them and could place them in the correct genus, either the original Geoplana or other one.

But guess what? Ogren and Kawakatsu did that in 1990 and now we are in 2012 and the situation remains the same. Those poor planarians species are still waiting in that taxonomic shelter until someone moves them to the place they belong to.

So how can we be sure about anything from those species? They were described in 1929, almost a century ago, and no one cared about them since then. And I guess the same occurs in other less cute and attractive groups, so while we describe hundreds or thousands of new species every year, other hundreds or thousands are left behind, forgotten inside dusty glasses in the zoological museums worldwide.

I just hope it will change someday.

Thanks for reading.

For more about systematics, you might want to see:

• A Brief History of the Kingdoms of Life
• Why I Don’t Trust Jack Horner 1: The Holes in the Old Triceratops Idea

—

References:

Baptista, V. & Leal-Zanchet, A. 2005. Nova espécie de Geoplana Stimpson (Platyhelminthes, Tricladida, Terricola) do sul do Brasil. Revista Brasileira de Zoologia, 22 (4), 875-882 DOI: 10.1590/S0101-81752005000400011

Du Bois-Reymond Marcus, E. 1951. On South American Geoplanids. Boletim da Faculdade de Filosofia, Ciências e Letras da Universidade de São Paulo, Série Zoologia, 16, 217-256.

Froehlich, E. M. 1955. Sobre Espécies Brasileiras do Gênero Geoplana. Boletim da Faculdade de Filosofia, Ciências e Letras da Universidade de São Paulo, Série Zoologia, 19, 289-339.

Graff, L. v. 1896. Über die Morphologie des Geschlechtsapparates der Landplanarien. Verhandlungen der Deutschen Zoologischen Gesellschaft, 73-95.

Marcus, E. 1951. Turbellaria Brasileiros. Boletim da Faculdade de Filosofia, Ciências e Letras da Universidade de São Paulo, Série Zoologia, 16, 5-215.

Mora, C., Tittensor, D., Adl, S., Simpson, A. & Worm, B. 2011. How Many Species Are There on Earth and in the Ocean? PLoS Biology, 9 (8) DOI: 10.1371/journal.pbio.1001127

Ogren, R. E. & Kawakatsu, M. 1990. Index to the species of the family Geoplanidae (Turbellaria, Tricladida, Terricola) Part I: Geoplaninae. Bulletin of Fuji Women’s College, 28, 79-166.

Rohland, N., Reich, D., Mallick, S., Meyer, M., Green, R., Georgiadis, N., Roca, A. & Hofreiter, M. 2010. Genomic DNA Sequences from Mastodon and Woolly Mammoth Reveal Deep Speciation of Forest and Savanna Elephants. PLoS Biology, 8 (12) DOI: 10.1371/journal.pbio.1000564

Schirch, P. F. 1929. Sobre as planarias terrestres do Brasil. Boletim do Museu Nacional, 5, 27-38.

As my friends know very well, I’m a fervent opponent of Jack Horner’s ideas. So naturally I had to start a series for analyzing and counter attacking some of his wackiest theories about dinosaur which, I hope, aren’t brainwashing an entire generation of paleoartists. Let’s get to know the star of the first post of the series: the Triceratops.

People might remember some time ago, it was everywhere in the news: “Triceratops didn’t exist”. That’s BS, even Horner himself said so. What he actually meant is that the ceratopsian dinosaur Torosaurus is nothing but an aged Triceratops: over the years the frill of – presumably male only – Triceratops would grow to the astounding size of Torosaurus‘ frill, about 2.5 meters (8.5 feet) long.

So in reality what should have been in the news is “Torosaurus didn’t exist”. In zoological nomenclature, a basic principle is that when a species received two different names, the earliest correctly published name, called senior synonym, takes precedence and thus should be used to name the species, excluding the later name (junior synonym). And since Triceratops was named before Torosaurus, Triceratops is the senior synonym and has to be the official one. But naturally media figured most mainstream people don’t know what a Torosaurus is, so their solution was to mess everything up and make some sensationalism, because that’s very surprising.

Naming issues aside, there are a few points about this theory that just seem off to me:

A little less known aspect of Horner’s theory (or maybe not so much anymore since he already released a paper about it) is that before becoming Torosaurus, Triceratops became something else first, and that is Nedoceratops (formerly Diceratops).

Nedoceratops skull. Photos by Andrew A. Farke, from Wikipedia, 2011

Nedoceratops have a long history of debates about its validity as a separated species or as a synonym for Triceratops (the small windows in the frills simply being caused by pathologies, for example). For Horner, the holes in the frill indicate the beginning of the transformation into Torosaurus, but that’s about where things get weird.

Drawing of the two Torosaurus skulls by Marsh, 1893.

Really now, how exactly does a hole form outta nowhere? So okay, Horner demonstrates that Triceratops’ frill is not entirely solid, some areas are thinner, and these are about the same areas where the holes appear in Torosaurus, so it apparently makes sense Torosaurus to be an old Triceratops, but even if dinosaur’s bones were very plastic and enabled many transformations as they grew, the bone retroceding and becoming so thin to the point where it disappears and leaves a hole is something not even sheer open-mindness is able to accept.

Reason number one is ceratopsian growth in general. Let’s use Protoceratops as the example since there are plenty of skeletons from individuals of varying ages, from baby to adult:

Protoceratops growth series. Photo by Harry Nguyen, 2008.

As you can see, the holes in the frill are present even in the youngest individuals. And if people can use Psittacosaurus quilled tail as an excuse to put quills in all other ceratopsians tails, then darn it, I WILL use baby Protoceratops as an argument that baby ceratopsians maintain holes in their frills all the way to adulthood, which takes us to reason number two, which is the baby Triceratops skull itself:

Baby Triceratops skull casting. Photo by BrokenSphere, from Wikipedia, 2009.

It’s not known (for me, at least) how old this baby was when alive, but judging by his size and features, he might very well been a newborn. Anyway, let’s take a look at his frills:

Baby Triceratops frill detail. Photo by Brokensphere, from Wikipedia, 2009.

So there, he does have some kind of holes in his barely formed frill. But these quickly disappear, as shown by the rest of the growth series. Maybe the thinner areas of Triceratops’ frill is a heritage of his baby form, maybe that part is naturally thinner for whatever reason. The point is that if it was true that Torosaurus is an old Triceratops, then the holes should have been present in all the younger forms just like Protoceratops, no matter how small they are compared to other ceratopsians.

But I give credit where credit is due. Horner presented solid evidence: the bones of Triceratops are spongy, which is characteristic of young individuals, which means that, true, Triceratops may not represent fully grown individuals. Still, it’s a long shot to assume Torosaurus is the mature form.

There is one little detail Horner overlooked in his theory: there IS a dinosaur that is bigger and is similar to Triceratops – even more than Torosaurus –, and whose remains were found in the Horseshoe Canyon formation in Alberta, which not only isn’t that far from Montana, but is also known to contain remains of dinosaurs also present in the Hell Creek formation, including Triceratops.

This dinosaur is called Eotriceratops xerinsularis, described in 2007 by Xiao-Chun Wu, Donald B. Brinkman, David A. Eberth and Dennis R. Braman.

Eotriceratops skull casting. Royal Tyrrel Museum, 2010.

I don’t think this picture does justice for it, so here’s what it may have looked like next to a standard Triceratops:

Eotriceratops size compared to Triceratops. Image by Conty, from Wikipedia.

There are some debates over the total lenght, but it’s quite larger than Triceratops. But then you can say “but PK, doesn’t ‘Eotriceratops’ mean “early Triceratops’? How can he be an adult Triceratops if he lived before Triceratops?”. Evidently the temporal range is estimative, and might not be entirely accurate; giving an error margin for this estimative, Eotriceratops would still be at the same time of Triceratops. If anything, Eotriceratops is the one that should have been theorized to be the aged Triceratops and be considered a synonym.

In his lecture Horner tries to argument there hasn’t been found any juvenile Torosaurus, but that’s false syllogism; I could, for example, argue that pterosaurs gave birth to live offspring since pterosaur eggs were never found. Except they were found, a few years ago, and they were soft-shelled eggs, for everyone’s surprise. What’s with this, you ask? Soft-shelled eggs are usually found in species that don’t take care of their offsprings, so this implicates that the scenario of mama pterosaur nurturing her babies in a nest, like birds do, is unlikely – but there might have been an exception here and there.

A female pterosaur preserved together with her egg. Lu Junchang, Institute of Geology, Beijing. Taken from CBC.

In other words, no juvenile Torosaurus was found because paleontologists have to rely on luck and patience, but some day they will be rewarded with such discovery. They found Tiktaalik, so why not?

The final hole in Horner’s theory is ceratopsian speciation. Amusingly enough, Horner himself kind of deliver that one: Early in his presentation, Horner show the growth series of the double-wattled cassowary, Casuarius casuarius, showing how different younger forms are compared to adult forms, and how the same thing could be applied to dinosaurs that could have been mistaken for separated species.

Double-wattled cassowary, Casuarius casuarius, growth series. Extracted from Horner's lecture "The Shape-Shifting Skulls of Dinosaurs".

That’s nice and all, but then you have to consider this guy here:

Dwarf cassowary, Casuarius benetti. Photo from Zoo Institutes.

This is the dwarf cassowary, Casuarius benneti, and if the name is any clue, he’s a smaller cassowary. He’s native to Papua-New Guinea and nearby islands, but his range also overlaps with the population of double-wattled cassowaries, and his skull looks like this:

Dwarf cassowary skull. Photo from Bird Skull Collection (skullsite.com).

So comparing it with the double-wattled cassowary growth series, things get kind of interesting, because the dwarf cassowary’s skull looks a lot more like a younger form of the adult double-wattled cassowary. You could easily put the dwarf cassowary skull in the diagram and pretend you didn’t know these were different species.

Now think of a place with lots of similar species, such as the African savannah and its wounderful antelope species variety. Some might have similar characteristics one to another, but they are all unique in their own right, even if their skeletons are virtually identical.

Naturally if you were some kind of alien paleontologist in the future and you dug up antelope fossils, you could too think that the tiny dik-dik is just a baby gazelle, which in turn is the younger form of the sable since all you have to work with are their bones.

Maybe the reason Torosaurus looks a lot like Triceratops is because they are very closely related, and might have lived in the same areas, but this doesn’t mean they are one and the same.

In the end, Horner’s idea is just slightly interesting, but is inherently flawed. Some say what he’s doing is constructive trolling, making outrageous theories to incite other paleontologists to show their work. That would be acceptable (if a little annoying indeed), but my credibility on him was buried for good in the very first episode of Terra Nova, where he’s the paleontological consulter, and allows one character to point out that the brachiosaur “supplement their diets with small reptiles”. Damn.

Anyway, I hope you enjoyed this article, and as usual, any questions all you have to do is comment and I’ll answer it.

Thanks for reading!

For more about dinosaurs, you might want to see:

• The Stiff-Tailed Dinosaur Syndrome

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References:

Scannella, J., & Horner, J. 2011. ‘Nedoceratops’: An Example of a Transitional Morphology PLoS ONE, 6 (12) DOI: 10.1371/journal.pone.0028705

TEDxVancouver – Jack Horner – The Shape-Shifting Skulls of Dinosaurs . 2009. Available on-line in: <http://www.youtube.com/watch?v=xYbMXzBwpIo>. Acess on December 5, 2011

Wikipedia. Triceratops. Available on-line in: <en.wikipedia.org/wiki/Triceratops>. Acess on December 5, 2011.

Wikipedia. Eotriceratops. Available on-line in: <en.wikipedia.org/wiki/Eotriceratops>. Acess on December 5, 2011.

Talking and exuberant-colored birds always exerted a strong fascination over human beings, and with me it couldn’t be different. Besides, the curiosity that something rare or lost arouses is an important factor to define a theme of interest to someone. Those two combined factors are the foundation that sustains a great interest on my part in extinct species of psittacids, mainly in those ones with little evidence of their doubtful existence.

Several psittacid species inhabitant of island paradises were extinct in the last centuries mainly due to hunting for food, trade to become pets and habitat loss. In this post I’ll deal with a specific species that’s said to have inhabited the Dominica Island, in the Lesser Antilles (Caribbean).

Dominica was firstly inhabited by the Caribbean Indians and later colonized by French and English. Hunting by the Indians is usually sustainable, not representing a great threat for the species.

The colonization by the Europeans, however, has been proved devastating, a common scenario not only in those islands, but also in several other points of the planet.

A forest in Dominica. Photo by Dirk.heldmaier, from Wikipedia.

The Dominican Green-and-Yellow Macaw (also known as Atwood’s Macaw or simply Dominican Macaw), Ara atwoodi, is known only from the report of Thomas Atwood. In his work “The history of the island of Dominica. : Containing a description of its situation, extent, climate, mountains, rivers, natural productions, &c. &c. Together with an account of the civil government, trade, laws, customs, and manners, of the different inhabitants of that island. Its conquest by the French, and restoration to the British dominions” from 1791, Atwood describes the local fauna, whose elements can be associated to the species currently known to the region, with the exception of a kind of psittacid no more found there and that differs from the other ones known in the island (Amazona arausiaca and A. imperialis, which Atwood probably considered a single species in his description) or anywhere else on the planet. The following is the excerpt, adapted to the modern English:

‘’The macaw is of the parrot kind, but larger than the common parrot, and makes a more disagreeable, harsh noise. They are in great plenty, as are also parrots in this island; have both of them a delightful green and yellow plumage, with a scarlet-colored fleshy substance from the ears to the root of the bill, of which color is likewise the chief feathers of their wings and tails. They breed on the tops of the highest trees, where they feed on the berries in great numbers together; and are easily discovered by their loud chattering noise, which at a distance resembles human voices. The macaws cannot be taught to articulate words; but the parrots of this country may, by taking pains with them when caught young. The flesh of both is eat, but being very very fat, it wastes in roasting, and eats dry and insipid; for which reason, they are chiefly used to make soup of, which is accounted very nutritive.’’

Atwood's Description in ''The History of the Island of Dominica'', 1791.

It’s believed that it became extinct by the end of the 18^th century or beginning of the 19^th century. As there are no extant species of green and yellow plumage (excluding hybrids induced by humans), Austin Hobart Clark assumed that it belonged to a species not yet known to science, firstly including it in Ara guadeloupensis (which is said to inhabit the neighboring island Guadeloupe). With the discovery of Atwood’s account, it was considered distinct, receiving the status of species in 1908.

Considered a hypothetical species by most authors, Ara atwoodi usually isn’t included in non-specific publications that mention recently extinct macaws, which almost always only mention the Cuban macaw Ara tricolor, for being the only one known from preserved specimens, and subfossil forms like A. autocthones. Joseph Forshaw highlight that’s not even safe to associate the species to the genus Ara, due to the absence of specimens, either stuffed or bones, or even illustrations. The association was made by deduction, based on the term “mackaw” used by Atwood, where Clark notices that “his macaw is a bona fide member of the genus Ara”. That, however, didn’t exclude the possibility of being a similar but separated genus that evolved by isolation in the island.

Reconstruction following the picture published in David Day's ''The Doomsday Book of Animals''. Picture by Rafael Silva do Nascimento, 2009.

From the excerpt describing its physical characteristics and based in close species, some reconstructions of how it looked started to appear, though in shyer steps than in other more popular extinct birds. The most widely known is the one present in David Day’s work “The Doomsday Book of Animals” (1981), which depicts a macaw well distinguished from the species whose appearance was known, not having the portion of bare skin on its face, consisting merely of a closed portion, but following the color pattern described by Atwood. Most posterior reconstructions are based on this picture. Other obscure species with a similar history are portrayed, like Ara erythrocephalus from Jamaica, which was also reported having green and yellow feathers, but with a red head. The color as it was described and the observation of extant species suggest a pattern similar to the one found in Ara ararauna and maybe in A. martinicus from the neighbor island Martinica (another hypothetical extinct species), with blue replaced by green. Also reported from Jamaica, but not creditable by most sources, is A. erythrurus, said to be similar to A. ararauna, but with an entirely red tail. Julian Hume in his book “Extinct Birds” to be released in February 2012, which also have Michael Walters as author, portrayed the species according to this idea, however without having the portion of bare skin on the face painted red, but only the forehead of this color. Since I didn’t have access to the work of Walters and Hume, I’m not aware of the reason for such a reconstruction, but considering that the reddish facial portion, usually seen as a distinct feature of A. atwoodi, may be simply excitation as observed in A. ambiguus, A. militaris and A. rubrogenys, this macaw may have been represented in a “calm” situation. Both A. ararauna and A. glaucogularis can show traces of redness on the face, being more evident in the last, so if A. atwoodi was truly a close relative, this feature might be more advanced in this species. A color pattern that recalls the described by Atwood is found in the pet market as in the hybrids Catalina (A. ararauna x A. macao) and Harlequin (A. ararauna x A. chloropterus), where the back is green and the belly varies from shades of yellow to bright orange.

I've made this reconstruction following the theory that A. atwoodi was closely related to A. ararauna. Some elements, such as the black patch below the bill, are highly speculative.

While I see sufficient evidences to declare the existence of a different form of macaw that once inhabited Dominica, its real appearance will remain a mystery until new evidences came to the surface, whether they are lost reports or subfossil bones.

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References:

Atwood, T. 1791: The History of the Island of Dominica. London: Frank Cass and Co.

BirdLife International (2011) Species factsheet: Ara atwoodi. Available on-line in: < www.birdlife.org/datazone/speciesfactsheet.php?id=30080>.  Acess on December 6^th, 2011.

Clark, A. H. 1908. The Macaw of Dominica Auk, 25, 309-311

Forshaw, J. M. & Cooper, W. T. 1977: Parrots of the World. T.F.H. Publications, Inc. New Jersey.

Fuller, E. 1987: Extinct Birds. Facts on Files Publications. New York.

Maas, P. H. J. 2007: Dominican Green-and-Yellow Macaw. In: TSEW. The Sixth Extinction Website. Available on-line in: <www.petermaas.nl/extinct/speciesinfo/dominicanmacaw.htm>. Acess on December 6^th, 2011.

Many-feathers. Catalina Macaw. Available on-line in: < www.many-feathers.com/Catalina-Macaw.htm>. Acess on December 6^th, 2011.

Rothschild, W. 1907: Extinct Birds. Hutchison, London.

Williams, M. I. & Steadman, D. V. 2001: The historic and prehistoric distribution of parrots (Psittacidae) in the West Indies. Pp 175-489 in Biogeography of the West Indies: patterns and perspectives. 2nd ed. (Woods, C. A. & F. E. Sergile, eds.) Boca Raton, FL: CRC Press.

Hello everyone, PK here, which means it’s time for some good old paleoartistic criticism and bashing of current ideas! So enjoy today’s topic: dinosaurs tails.

As everyone knows, for the longest time since their formal description in the mid-19th century, dinosaurs were thought to be tail-draggers in the same fashion as reptiles, because reptiles are lazy and so should be dinosaurs since they were reptiles. Or so it seemed, as it was about in the 70′s when the “dinosaur renaissance” came into scene, replacing the slow-moving and swamp-dwelling giant lizards for active, warm-blooded animals.

And considering the topic, the most important of all these changes is that they now had their tails off the ground, but then things sort of went downhill from there: artists started to depict their dinosaurs with increasingly elevated tails, to the point where, in the last 10 years or so, dinosaurs are always pictured as having their tails completely parallel to the ground and almost pointing upwards!

I, for one, am convinced that this idea was something paleoartists – both amateur and professionals – simply misunderstood. Namely – while dinosaurs may very well been able to maintain their tails parallel to the ground, they may not have done so at all the time.

There’s one important factor about dinosaurs that I have the slight feeling some artists overhead, or just plain ignore for a more dramatic effect, is that dinosaurs are animals just like the ones that live today, and as such, dinosaurs most certainly would get very tired sometimes. See, there is not a single animal in the world that maintains any of its limbs in a certain position for too long, and dinosaurs would be no exception: maintaining their tails elevated in a horizontal posture for so long would be exhaustive.

In other words, dinosaurs were able maintain their tails above the ground, but just enough; namely, they had droopy tails for the most part.

I went to brainstorm with RSN about this possibility, and he reminded me of an important detail: some dinosaurs were found with fossilized tendons on their tails. So naturally I had to research about that and what it would mean for the droopy-tail idea. One such evidence is found in the first ever Corythosaurus remains discovered by Barnum Brown in 1912, which is nice because for me ornithopods are the worst offenders of the rigid-tail idea. Now, please, take a look at this picture:

Corythosaurus casuarius skeleton, by Barnum Brown, 1916.

Not only the creature’s skeleton was found almost complete, skin impressions are also present, but take a closer look at the tail; specifically the base, right above the ischium. Those distinct line markings you see were made by tendons which, supposedly, helped the animal maintain his tail in the same horizontal position as seen in this skeleton. But where exactly does this leave the idea that dinosaurs had droopy tails then? Go ahead, I’ll give you a few seconds…

You see it yet? Ok, I’ll make it more clear with this other picture:

Drawing of the fossil, by Barnum Brown, 1916.

Yes, as you can see, those tendons were present mainly at the very base of the tail. Not only that, but consider the caudal vertebrae also have a slight irregular shape when lined horizontally, but not so much if you curve it downwards – this also happens in other dinosaurs such as sauropods. In other words, the tendons only helped the Corythosaurus to maintain the first half or so of its tail elevated.

From what could be inquired from mummified hadrosaurid findings, duck-billed dinosaurs (as they are informally called) had a longer digestive system than other plant-eating dinosaurs. The elevated tail base means there is some more free room for processing the plant matter. Maybe not for much, but it was a very welcome addition.

But naturally dinosaurs didn’t had tails to digest plants. Tails are primarily used for balance, and in some animals it can also serve as a weapon, other might use them to call attention of mates or signalizing for each other in a group. Some animals, however, have no need for any of these, so what usually happen is that the tails have so little impact on its lifestyle that they quickly degenerate, resulting in stumps or completely disappearing. Just like what happened to us humans.

But dinosaurs had big tails – except for those who became birds and other not-quite-bird-yet small theropods such as Epidexipteryx – it’s one of their trademarks that make them so different from any other large animal today. But not all dinosaurs used their tails for balancing.

Epidexipteryx hui skeleton, discovered in 2008. Notice the shortened tail, compensated by the elongated feathers. Photo from National Geographic.

For example, armored dinosaurs such as ankylosaurids, nodosaurids and stegosaurids. With a low profile and sturdy legs, having a tail for balance isn’t needed, but they still had well formed tails for a single reason: they were mortal weapons. Stegosaurids had piercing spikes, nodosaurids had rows of sharp blades and ankylosaurids had a mass of bone at the tip that formed a fearsome weapon against predators.

Tail club of Euoplocephalus tutus, an ankylosaurid. Photo by Ghedoghedo, from Wikipedia, 2011.

Sauropods, at least the ones without extreme long neck lenghts, wouldn’t need such a long tail for counterbalancing; their torso might have been enough. These would then be free to be used as weapons since they couldn’t back-off predators with sheer size alone, and surely enough, some sauropods such as Diplodocus had elongated tails that ended in thin bones that could be used as whips, and the chinese Shunosaurus had a bone club similar to that of ankylosaurids. Both dinosaurs, while much larger than any living terrestrial animal, are visibly rather small for sauropod standards.

Skeletal reconstruction of the Spinophorosaurus nigerensis from Africa, which closely resembles the chinese Shunosaurus both in size and weaponry. Souce: Remes K, Ortega F, Fierro I, Joger U, Kosma R, et al. (2009).

On the same note, brachiosaurids had huge front legs which supported an extreme neck, but their tails were very small compared to other sauropods. So small in fact, they couldn’t be used for anything and one wouldn’t be surprised if their tails became stumps had they survived long enough.

Brachiosaurus brancai (now Giraffatitan brancai). Picture by Paul Olsen, 1988.

Now there are the odd ones: Ceratopsians. The larger ceratopsian that dominated North America in the late Cretaceous period landscape are known for their huge frills and huge horns and sturdy bodies… and for having rather pathetic-looking tails. These were relatively short and thin, and it’s hard to imagine that ceratopsians used them for counterbalancing their skull – which is in some way confusing since they might have been quite heavy even with the “windows” on the frills to decrease the weight.

And even odder ones: Pachycephalosaurids. These dinosaurs are known for their thick skulls which they used for head-butting contests (yes), but they are also known for the woven net of tendons at the tip of their tails. The total opposite of what usually happens.

So where do ornithopods such as Corythosaurus fall in all of this? My guess is that they used them for balance, but only when running on their hind legs. See, duck-billed dinosaurs had very small arms compared to his legs, with hoof-like hands, which is good evidence that they could walk on four legs as well as two legs.

A grazing Corythosaurus did not need their tails to be parallel to the ground; their arms would enable them to stand with a droopy tail. But on the sign of danger, things change: unsuitable to handle the stress that running on all four would cause, they would stand on two legs and run; the tail tendons then would enable the animal lift his tail to counterbalance its body while running. In this respect, the dinosaur would then function more like a theropod rather than a ceratopsian, per se. When away from danger, the tendons relax and the animal tail goes back to its droopy position. Corythosaurus would then look something like this (thanks RSN for the picture!):

Corythosaurus in relaxed position (above) and running from danger (below). Picture by Rafael Silva do Nascimento, 2011.

So there you have it. Dinosaurs had many uses for their tails, and just because they had tendons and warm blood it doesn’t mean they had steel rod for tails. While Corythosaurus is used as a starting point for the idea, keep in mind other dinosaurs also could have droopy tail, including the ones that used their tails for balance such as theropods.

So if you ever see a picture of a dinosaur, any kind of dinosaur, standing still or having a nice stroll, and said dinosaur is doing it while having their tails completely parallel to the ground, you’re allowed to shout “WRONG!”, because that dinosaur must be tired as heck of having his tail like that.

Hope everyone enjoyed reading my article; if you have any questions just comment and I’ll answer it.

Thanks for reading!

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References:

Leonardo, the mummified dinosaur. Available on-line in: <www.youtube.com/watch?v=ihifMrV3-pY>. Acess on December 1st, 2011.

Paul, G. S. et al. 2010: The Princeton Field Guide to Dinosaurs. Princeton University Press.

Wikipedia. Corythosaurus. Available on-line in: <en.wikipedia.org/wiki/Corythosaurus>. Acess on December 1st, 2011.

Since ancient times, living beings were classified as either plants or animals and Linnaeus retained this system in his great work Systema Naturae in the 18^thcentury, where he divided nature in three kingdoms: Regnum Animale (animal kingdom), Regnum Vegetabile (plant kingdom) and Regnum Lapideum (mineral kingdom). This system was not intended to reflect natural relationships among living organisms, since Linnaeus was a Christian and believed that all life forms were created separately by God himself just as they are today, but was created to make the study of living beings easier.

Linnaeus and the two kingdoms of life. Painting by Alexander Roslin, 1775.

When the first unicellular organisms were discovered by Antoine van Leeuwenhoek in 1674, they were placed in one of the two kingdoms of living beings, according to their characteristics. It remained so until until 1866, when Ernst Haeckel proposed a third kingdom of life, which he called Protista, and included all unicellular organisms in it.

Haeckel and the three kingdoms. Photo by the Linnean Society, 1908.

Later, the development of optic and electronic microscopy showed important differences cells, mainly according to the presence or absence of distinct nucleus, leading Édouard Chatton to distinguish organisms in prokaryotes (without a distinct nucleus) and eukaryotes (with a distinct nucleus) in a paper from 1925. Based on it, Copeland proposed a four-kingdom system, moving prokaryotic organisms, bacteria and “blue-green algae”, into the kingdom Monera. The idea of a ranking above kingdom came from this time and so life was separated in two empires or superkingdoms, Prokaryota (Monera) and Eukaryota (Protista, Plantae, Animalia).

Two empires and four kingdoms

Since Haeckel, the position of fungi was not well established, oscillating between kingdoms Protista and Plantae. So, in 1969, Robert Whittaker proposed a fifth kingdom to include them, the called Kingdom Fungi. This five-kingdom system remained constant for some time; Monera were prokaryotes; Plantae were multicellular autotrophs (producers); Animalia multicellular consumers; and Fungi multicellular saprotrophs (decomposers). Protista was like the  trash bag, where anything that doesn’t fit in the other 4 kingdoms was placed in.

Whittaker and the five kingdoms. Photography source: National Academy of Sciences: Robert H. Whittaker (1920—1980) - A Biographical Memoir by Walter E. Westman, Robrt K. Peet and Gene E. Likens.

With the dawn of molecular studies around 1970, significant differences were found inside the Prokaryotes, regarded, for example, to the cell membrane structure. Based on those studies, Carl Woese divided Prokaryota in Eubacteria and Archaeobacteria, emphasizing that the differences between those two were as high as the ones between them and the eukaryotes. This later gave rise to a new higher classification of life in three domains, Bacteria, Archaea and Eukarya.

Woese and the three domains. Photo from Photo from News Bureau - University of Illinois, given by IGB (Institute for Genomic Biology).

By the end of the 20^th century, Thomas Cavalier-Smith, after intense study of protists, created a new model with 6 kingdoms. Bacteria and Archea were put together in the same kingdom, called Bacteria. Protists were divided in two kingdoms: (1) Chromista, including Alveolates (Apicomplexa, parasitic protozoa like Plasmodium; Ciliates and Dinoflagellates), Heterokonts or Stramenopiles (brown algae, golden algae, diatoms, water moulds, etc) and Rhizarians (like Radiolaria and Foraminifera), among others; and (2) Protozoa, including Amoebozoa (amoebas and slime moulds), Choanozoa (choanoflagellates) and a set of flagellated protozoa called Excavata. Glaucophytes, red and green algae were classified inside the kingdom Plantae.

Cavalier-Smith and his two new kingdoms. Photo from Department of Zoology - University of Oxford.

From the 21th century on, a phylogenetic approach to classify living beings has gained strength. After a lot of molecular analyses using different genes, the real evolutionary relationship among Eukaryotes is still not clear. However, the following groups are supported by most phylogenetic trees:

(1) Archaeoplastida (or Plantae): glaucophytes (Glaucophyta), red algae (Rodophyta) and green plants and algae (Viridiplantae)

(2) Chromalveolata: Stramenopiles or Heterokonta, haptophytes (Haptophyta), cryptomonads (Cryptophyta) and Alveolata.

(3) Rhizaria: Foraminifera, Radiolaria and some amoeboid protozoa

(4) Amoebozoa: amoebas and slime moulds

(5) Opisthokonta: animals, fungi, choanoflagelates

(6) Excavata: many flagellate protozoa. This group, however, isn’t as well supported as the other ones.

The current (maybe not so) well-established groups of organisms

So, as we can see, the Eukaryotes’ case is yet to be solved, but we hope that further molecular studies will helps us understand better how the tree of life branches.

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References:

Baldauf, S. L. et al. 2000: A Kingdom-Level Phylogeny of Eukaryotes Based on Combined Protein Data. Science 290, 972-977.

Cavalier-Smith, T. 2004: Only six kingdoms of life. Proceedings of the Royal Society B 271, 1275-1262.

Rogozin, I. B. et al. 2009: Analysis of Rare Genomic Changes Does Not Support the Unikont–Bikont Phylogeny and Suggests Cyanobacterial Symbiosis as the Point of Primary Radiation of Eukaryotes. Genome, Biology and Evolution 1, 99-113.

Wikipedia. Kingdom (Biology). Available on-line in: <en.wikipedia.org/wiki/Kingdom_(biology)>. Acess on December 5th, 2011.