Limusaurus, snow and GCSEs

Above; a rather awkward looking moa skeleton labelled as belonging to Dinornis robustus. It turns out to be a sexual variant of Dinornis giganteus, which is the name that takes priority.

Above; the skulls of varioous Moa species (the identity of which is a mystery to me).

Above; the skull of Limusaurus can be seen on the left, the small arm in the center and the pelvis to the right.

I have not been posting much recently due to other enagements such as revision for my GCSE exams. So rather than researching more on the natural wonders of the world I have been memorizing and reading through chemistry and physics text books.

But I have had a lucky break. Due to the snowy weather recently in good old Britannia I have had many days off school to revise for my exams and maybee do a little research (ok a lot of reading was not revision). This post is nothing to do with anything I have been reading about either. It is the unusual and coincidential similarity between the mid Jurassic Ceratosaur Limusaurus from China and the late Pleistocene Ratite birds of New Zeland: the Moas.

The best way to understand how extinct animals lived is to compare them with similar animals in a modern environment. Now of course Moas are not alive today, but they were around much more recently than Limusaurus and as a result we have much better knowledge of them.

The similarities begin in the head. The skull is small. There is a toothless beak on both the upper and lower jaws and the dentaries and upper jaws on both animals curve down towards their tips. The eye socket is large in proportion to the skull and numerous fenestrations are present to save weight.

Postcranial similarities between the two also exist. The neck is long, but longer in the Moa. Both have reduced forelimbs; Limusaurus has atrophied forelimbs with only 2 functional digits, the Moa does not even have a gelnoid socket in its shouler girdle. In contrast the hindlimbs are very well developed. The tibia is considerably longer than the femur.

The key differences between these two animals are the facts that Limusaurus has a tail, the Moa has an unsatisfactory caudal series to say the least and that the feet of the Moa are much larger relative to their size than those present in Limusaurus. This suggests that Limusaurus was a faster runner than the Moa.

One final point is that both are preserved with gastroliths, suggesting that most of the mastication and grinding of food took place in the gizzard.

More on Limusaurus and Moas later on.

Yet more book reviews, I wonder what Greg Paul has been up to over the last few years?

It could only be his recently published Feild Guide to Dinosaurs. This is brilliant; finally Gregory S Paul has done a referance guide on Dinosaurs. The first half consists of info on dinosaur biology, the second is a comprehensive and classificatinally organized series of breif fact files on almost every known dinosaur species. Many of which are accompanied by a skeletal reconstruction and an accompanying profile style life reconstruction.

Above; an example of one of the pencil drawings that accompany the dinosaur fact files (Eoraptor)

Through out the book are nice paintings and pencil drawings of the animals in question, many of which will be familiar to you I'm sure. He covers recently described species such as Austroraptor and Tethyshadros.

One key habit of Greg Paul is to lump species often placed in different genus catergories in to the same genus (Tyrannosaurus bataar and Tyrannosaurus rex for example). Personally I have no gripe with this as he does not describe the animals genus by genus as most dino reference guides do, but species by species therefore still creating a distinction. He also puts the more generally accepted genus name in brackets to prevent confusion. One very interesting feature of the book is the placement of Guanlong wucaii in the genus Monolophosaurus. The justification for this may be questionable, but to be honest with you it does not bother me in the slightest.

The fact files are rather brief, but cover all the necessary data (except the date of description and who by). The main reading is in the front of the book where he goes through all the introductory stuff in great detail.

So; to sum it all up. Great drawings, great detail and lots of dinosaurs. Definately worth a read.

The book everyone has been talking about; Archosauria A new look at old Dinosaurs!

I recently received my copy of John McLoughlin's book via the post. It is a very interesting book published in 1979 and the illustrations are made by the author. I always love it when authors illustrate their own books because it allows them to get their ideas across in a more direct way.

What I believe is really monumantal about this publication is the fact that his dinosaurs were very modern by 1979 standards. The Theropods walked with horizontally held backs and had their tails held clear off the ground. Even more remarkable is that his reconstructions of Ceolurosaurs all feature not the scaly critters of old lore, but active feathery birdy creatures!!!!!: In the 1970's!!!!!!! I am not sure if he is still alive, but if he was around to see the discovery of feathered dinosaurs he must have felt so satisfied.

The book itself is not an average dinosaur book. It does go through the basic sort of things general dinosaur books do, but also talks about metabolism, crocodile hearts and various other interesting biological ideas about dinosaurs.

The main thing about the book has to be the drawings. They do look a bit strange compared to modern restorations. The Dromaeosaurus in my opinion looks fantastic. The face looks somewhat human in a bit of a disturbing way and the positioning of its legs does not look right, but the expression on the face is fantastic.

The Tyrannosaurus looks as if he has been reconstructed with gums covering his teeth as in an alligator, giving it a rather peaceful character, despite the fact that it is chewing on the remains of what looks like a Hadrosaur.

Another interesting reconstruction is that of his Triceratops, which has a frill connected to its shoulders by a sheet of muscle, giving it an indistinct neck. This idea never caught on, but is an out of the box way of thinking about these animals; at least he was right about the feathered Ceolurosaurs. Yet again the expression of the Triceratops is almost irresistably adorable.

Apparently he has also done a book on Therapsids! Yay; one of my most favorite groups of animals after Theropod Dinosaurs. How many popular books have ever been written on Therapsids? Well; I'm getting it. I think its called Therapsids A new look at old Synapsids. He hints to its publication in Archosauria.