Thursday 31 July 2008

Art #8: Three Pachycephalosaurs


"Three Pachycephalosaurs"
Coloured pencil illustration, July 2008
Adapted from Luis Rey's illustrations in Dinosaurs: The Most Complete, Up-To-Date Encyclopedia for Dinosaur Lovers of All Ages

Top: Stegoceras validum Lambe, 1902
Pachycephalosauridae; Marginocephalia; Ornithischia; Sauropsida; Chordata
From Late Cretaceous North America

Middle: Pachycephalosaurus wyomingensis Gilmore, 1931
Pachycephalosauridae; Marginocephalia; Ornithischia; Sauropsida; Chordata
From Late Cretaceous North America

Bottom: Dracorex hogwartsia Bakker et al., 2006
Pachycephalosauridae; Marginocephalia; Ornithischia; Sauropsida; Chordata
From Late Cretaceous North America

The pachycephalosaurs, or "bone-heads" are known to be the closest relatives to the ceratopsians, or "horned faces", like the well known Triceratops. They both share the formation of thickened bone around the edges of the head (hence "Marginocephalia"), which in the advanced ceratopsians is turned into a frill. The most well known pachycephalosaur is the quite hard to pronounce and spell Pachycephalosaurus, meaning "thick-headed lizard". It is probably obvious that these animals used their thickened skulls for protection or fighting, but the bone, although thick, might have been fragile and easily shattered, so probably not for head on fighting. 

While Stegoceras ("roof head") and Pachycephalosaurus have been known for around a century, Dracorex hogwartsia was discovered very recently and named as a new species and genus. My colour scheme for this animal was influenced by both parts of its name: Dracorex means "king dragon" in Latin, and hogwartsia honours the Hogwarts School of Witchcraft and Wizardry in J K Rowling's world-famous Harry Potter series of books. The colours of Gryffindor house in the books are red and gold, and both also look quite draconian, in the true sense of the word, meaning "dragon-like". Despite all this, Dracorex might prove to just be a juvenile Pachycephalosaurus, and it would be a shame to lose this most magnificent of recent dinosaur names, most of which seem to be named after a locality and/or a person.

I realised while drawing Stegoceras that my picture was going to look a bit like George Washington, so the colours were likewise influenced by the United States. The colour scheme for Pachycephalosaurus is based on a "rhubarb and custard" combination I quite like.

Art #7: Confuciusornis sanctus in life and death



Photo:
Confuciusornis sanctus Hou et al., 1995
Confuciusornithidae; Confuciusornithiformes; Aves; Chordata
Manchester Museum
July 2008

Artwork:
"Confuciusornis sanctus in life and death"
Same taxon as above
Coloured pencil illustration, July 2008

Confuciusornis sanctus was a very early bird dating from the Early Cretaceous Period of China (about 120 million years ago). It is known to be a true bird and not just a dinosaur (ignore the fact that birds are dinosaurs here, because not all dinosaurs are birds!) due to a few features, notably the lack of teeth and the absence of a long tail made up of separate vertebrae. Instead, Confuciusornis, like all modern birds, has a pygostyle, a bone made up of these separate vertebrae now fused. Notice that although there are many birds today with apparently long tails, such as pheasants, quetzals, peacocks and birds of paradise, they all have a short bony pygostyle to which these feathers are attached. Dinosaurs (non-avian ones at least) did not possess the pygostyle, and had a long set of caudal vertebrae instead. So although Archaeopteryx (photo, drawing and more in a future post I hope!) is considered a bird, it does have teeth, as some other primitive birds like Hesperornis, and it has a long tail and no pygostyle, amongst other adaptations not yet gained, i.e. a well-developed keel on the sternum for breast muscles to attach to.

The fossil pictured in the photograph is real, and the plaque next to it in Manchester Museum states that it was purchased. The feathers can clearly be seen, and although most Confuciusornis specimens are found with two long tail feathers imprinted, this specimen does not, so it could represent sexual dimorphism, where the male and female look different. Perhaps females weren't as colourful as the males, and also perhaps they had no need for long tail feathers. You can also clearly see the claws on the hands, which some modern birds also retain (like the hoatzin). The claws are very similar to those of the ancestral dinosaurs which gave rise to Confuciusornis and other birds. It also looks as if the bird had an erectile crest of feathers on the nape of its neck, I have tried to illustrate that in my drawings. The colour scheme was loosely based on the colours of China, seeing as the bird is from there, its name honours one of the most well known philosophers and the main religion of the country, and the fact that the Olympics starts there pretty soon.

Monday 28 July 2008

Photos of the Day #18: Two Carnivores



Top photo:
Lion paw bones
Panthera leo (Linnaeus, 1758)
Felidae; Carnivora; Mammalia; Chordata
Booth Museum of Natural History, Brighton
July 2008

Bottom photo:
Two-spotted Palm Civet
Nandinia binotata Gray, 1830
Nandiniidae; Carnivora; Mammalia; Chordata
Manchester Museum
July 2008

A quick note about the "palm civet", also known as the Tree Civet or African Palm Civet: it is no longer considered to be related to the civets (Viverridae), like the Owston's civets or genets, binturongs and true palm civets (those are the guys who eat the coffee beans and very high-priced, undoubtedly smelly, coffee comes out of the other end). Instead, Nandinia binotata is considered an early split from the branch of the Carnivora which led to the cats, hyaenas, civets, mongooses and other minor carnivore families. The name "two-spotted" and the species epithet binotata both refer to the small silvery-white spots on either shoulder which can't be seen clearly in this specimen, or indeed in most photos I have seen. I suppose it needs a new name, since no parts of it are actually that accurate!

Next post will hopefully include a drawing of Confuciusornis sanctus and a photo of the fossil from Manchester Museum.

Monday 21 July 2008

Photo of the Day #17: Red-crested Pochard


Red-crested Pochard
Netta rufina (Pallas, 1773)
Anatidae; Anseriformes; Aves; Chordata
London Wetland Centre
January 2008

Thursday 17 July 2008

Photo of the Day #16: Spectral Tarsiers

Spectral Tarsiers
Tarsius tarsier (Erxleben, 1777)
Tarsiidae; Primates; Mammalia; Chordata
Natural History Museum at Tring
July 2008

Just one comment this time: cute tarsier at the front, scary pissed off looking tarsier behind.

Wednesday 16 July 2008

Photo of the Day #15: Pale Pitcher Plant


Pale Pitcher Plant
Sarracenia alata Alph.Wood
Sarraceniaceae; Ericales; Magnoliopsida; Magnoliophyta
Oxford Botanic Gardens
July 2008

The pitcher plants belong to two unrelated families: the Sarraceniaceae of North America, and the Nepenthaceae of the Old World. The flowers of the North American pitchers, as pictured above, are large and showy, yet dull in colour. But of course the most interesting thing about pitcher plants is, like sundews and Venus fly-traps, they are carnivorous, catching insects in their specially modified leaves shaped like pitchers, even coming with a lid to keep rainwater out! I tried keeping a pitcher plant. It died. 

Tuesday 15 July 2008

Photo of the Day #14: Walliserops trifurcates

Walliserops trifurcates Morzadec, 2001
Acastidae; Phacopida; Trilobita; Arthropoda
Oxford Museum of Natural History
July 2008

Trilobites were amazing things, and if you believe the storyline in Journey to the Center of the Earth (2008), then they still are amazing things. But for the rest of us, trilobites became extinct way before the first dinosaurs even appeared. The W. trifurcates depicted is just one of c.17,000 known species, itself dating from the Devonian Period (about 420-360 million years ago), and was found in Morocco, where many unusual forms seem to have existed in shallow seas. Even Richard Fortey himself, a veteran trilobite expert based at the Natural History Museum, London, was surprised and amazed at such a bizarre looking animal. Just look at that projection! What the hell could that have been for?

Trilobites possessed very advanced eyes for arthropods (jointed-legged invertebrates), which you can see on Walliserops; the level of detail preserved in such fossils is just incredible.

Monday 14 July 2008

Photo of the Day #13: Immature Grey Heron


Grey Heron
Ardea cinerea Linnaeus, 1758
Ardeidae; Ciconiiformes; Aves; Chordata
Enfield Town Park, Enfield, North London
July 2008

Today whilst walking in my local park, I had some wonderful views of an immature grey heron fishing in the New River. The individual first started in an area where quite a lot of people go to feed the ducks etc., except the food goes uneaten and there is an algal bloom all over that part of the river, and probably not many fish for the heron. Also it was being harassed by people who obviously thought it wanted bread, despite it flying away twice to a more sheltered spot. Finally, it gave up and went a few hundred metres along the river to a much more secluded part, where I could get much better views, and more importantly, the bird could feed in peace without a shower of mouldy bread.

Tuesday 8 July 2008

Art #6: Five Hadrosaurids



"Five Hadrosaurids"
Coloured pencil illustration, July 2008
Adapted from Luis Rey's illustrations in Dinosaurs: The Most Complete, Up-To-Date Encyclopedia for Dinosaur Lovers of All Ages

Top left: Parasaurolophus walkeri Parks, 1922
Hadrosauridae; Ornithopoda; Ornithischia; Sauropsida; Chordata
From Late Cretaceous North America
With colour scheme inspired by the Hoopoe (Upupa epops)

Bottom left: Corythosaurus casuarius Brown, 1914
Hadrosauridae; Ornithopoda; Ornithischia; Sauropsida;
ChordataFrom Late Cretaceous North America
With colour scheme inspired by the Southern Cassowary (Casuarius casuarius)

Top centre: Lambeosaurus lambei Parks, 1923
Hadrosauridae; Ornithopoda; Ornithischia; Sauropsida; Chordata
From Late Cretaceous North America
With colour scheme inspired by the Mandarin Duck (Aix galericulata)

Bottom centre: Olorotitan arharensis Godefroit et al., 2003
Hadrosauridae; Ornithopoda; Ornithischia; Sauropsida; Chordata
From Late Cretaceous Russia
With colour scheme inspired by the Roseate Spoonbill (Platalea ajaja)

Right: Saurolophus osborni Brown, 1912
Hadrosauridae; Ornithopoda; Ornithischia; Sauropsida; Chordata
From Late Cretaceous Mongolia & North America
With colour scheme inspired by the Secretary Bird (Sagittarius serpentarius)

Hadrosaurids are the "duck-billed" dinosaurs, a specialised group of ornithopods (see Art #4) from the very end of the dinosaurs' reign in the Late Cretaceous (up to 65 million years ago). There are two subfamilies: Hadrosaurinae, containing such beasts as Edmontosaurus and Saurolophus; and Lambeosaurinae with the crested hadrosaurids such as most of those depicted above. The wonderful diversity of crests may have been used for producing resonating sounds, and were likely to have had warning colorations.

I have added a twist to the coloration; using colours of extant birds which bear some similarity to the dinosaurs. The likeness is uncanny in the Corythosaurus casuarius and the cassowary; note that the species name of the dinosaur is the same as that of the bird. The eye spot on the Olorotitan is nothing to do with the roseate spoonbill, but I felt it needed some more colour than brown on the crest!

Sunday 6 July 2008

Art #5: Eudimorphodon



"Eudimorphodon" by Hattie Hassan (my mum)
Coloured pencil sketch, June 2008
Adapted from Luis Rey's illustrations in Dinosaurs: The Most Complete, Up-To-Date Encyclopedia for Dinosaur Lovers of All Ages

Eudimorphodon ranzii Zambelli, 1973
Campylognathoididae; Rhamphorhynchoidea; Pterosauria; Sauropsida; Chordata
From Late Triassic Italy

A quick sketch of a pterosaur. I left my book, paper and pencils out and Mum drew her own and gives her permission to put it on my blog!

On a scientific note, Eudimorphodon is one of the earliest pterosaurs (more commonly, but erroneously known as "pterodactyls"), the flying reptiles that accompanied dinosaurs throughout the Mesozoic that came in an amazing array of forms and sizes, from sparrow-sized up to that of a small plane! Eudimorphodon, however, had a wingspan of only about a metre.

Art #4: Three Ornithopods


"Three Ornithopods"
Coloured pencil illustration, June 2008
Adapted from Luis Rey's illustrations in Dinosaurs: The Most Complete, Up-To-Date Encyclopedia for Dinosaur Lovers of All Ages

Top left: Leaellynasaura amicagraphica Rich & Rich, 1989
Hypsilophodontidae; Ornithopoda; Ornithischia; Sauropsida; Chordata
From Early Cretaceous Australia

Top right: Iguanodon bernissartensis Boulenger, 1881
Iguanodontidae; Ornithopoda; Ornithischia; Sauropsida; Chordata
From Early Cretaceous Belgium

Bottom: Ouranosaurus nigeriensis Taquet, 1976
Ornithopoda; Ornithischia; Sauropsida; Chordata
From Early Cretaceous Niger

These ornithopods ("bird-feet") are all from the Early Cretaceous Period (146-110 million years ago), and spread across the world, being from both Laurasia (the continental mass made up of modern day North America and Eurasia, except India) and Gondwanaland (the southern land mass made of South America, Africa, Arabia, India, Madagascar, Australia and Antarctica). The genus Iguanodon was also much more widespread, with species found across Laurasia.

Leaellynasaura was named after the discoverers' daughter, Leaellyn Rich, and the species epithet, amicagraphica, roughly translates from Latin as "friends of geography", honouring the Friends of the Museum of Victoria and the National Geographic Society. Isn't etymology wonderful?