Avatar in fossil form

A new pterosaur find has just been published and named Ikrandraco avatar.  The creature has a long skull with teeth and a sturdy lower mandibular keel.  Two specimens have been found and the paratype IVPP V.18406 is illustrated.  The holotype IVPP V.18199 is a more complete specimen, but the skull preservation is overlaid by other bones.

Wang X., Rodrigues T., Jiang S., Cheng X. and Kellner A. W. A., 2014, An Early Cretaceous pterosaur with an unusual mandibular crest from China and a potential novel feeding strategy. Scientific Reports, 4/6329, doi:10.1038/srep06329

The name "Ikran" and "avatar" were chosen as the fossil skull shows similarities with the head shape of the fictional Ikran (mountain Banshee) from the science fiction film Avatar.

http://www.avatarmovie.com/index.html

Wow!

A recent paper published this year has revealed a wealth of pterosaur information from one find.  A bad weather event about 120 million years ago preserved the remains of 40 pterosaurs of a single colony along with 5 eggs.

Found at a site in the Turpan-Hami Basin near the Tian Shan Mountains in Xinjiang, China, this skull is a complete one of an assumed female specimen of Hamipterus tianshanensis.  It clearly shows a shallow crest and a pterodactyloid structure to the skeleton.

Remains of other individuals show a more prominent nasal crest and these are presumed males, consistent with the evidence found in Darwinopterus regarding male-female sexual dimorphism.

Alongside the remains were 5 pterosaur eggs, preserved in full form.  They have thin, soft, calcareous shells and a sturdy membrane on the inner side of the shell.
This find has been well studied by some of the biggest names in pterosaur research and it is a landmark find.  This is clear evidence of colonial behaviour and flocking in pterosaurs.  It also reinforces the ideas that some species display sexual dimorphism and it associates eggs with adult and sub-adult animals.
These specimens are now in the Beijing Palaeontology Museum (IVPP).

Wang X., Kellner A. W. A., Jiang S., Wang Q., Ma Y., Paidoula Y., Cheng X., Rodrigues T., Meng X., Zhang J., Li N. and Zhou Z., 2014, Sexually Dimorphic Tridimensionally Preserved Pterosaurs and Their Eggs from China, Current Biology. doi: 10.1016/j.cub.2014.04.054

Changes to the blog

Google - who host blogger - are making changes to their services.  Access to Google services is now going to be through @gmail accounts.  There has been no notification to weblog administrators about the change, but I have taken the precaution of assigning a Google Mail administrator for this blog to ensure that it will function when the changes are applied on ;

16^th June 2014

 Lets hope all goes well.

The Rotunda

 Scarborough Museum Services have been restructured over the past decade.  The geology collections are now housed in the Rotunda Museum at the end of Valley Road.

 Amongst the collections are two bones collected from the Taynton Limestone.  This one is catalogued SCARB-2000-1883 and carries a label 26G and another old hand written label "Bone of A Pterosaur".  This bone is a proximal Humerus from an unidentified pterosaur species.

 The second bone is catalogued SCARB-2000-1970 and has an old hand written label "Bones of Pterodactyl".  This is a rhamphorhynchoid wing metacarpal of an Middle Jurassic pterosaur.

A third specimen is on display and this is the Cast of the Pterodactylus antiquus specimen from Mannheim.  This was the first pterosaur to be published by Collini in 1784.

The Rotunda Museum is well worth a visit if you are in the Scarborough area.  It has very well organised displays and a wealth of local Jurassic material.  There is also a lot of information about the people who collected and published work on the specimens from the Yorkshire coast.

http://www.scarboroughmuseumstrust.org.uk/ 

Just a few streets away on Eastborough is Richard Widdowson's "Gems" shop where there are exceptional quality local fossil specimens for sale.  This fossil coast has some interesting geology and archaeology which should not be missed.

The power of X-rays

It is often the case that fossil specimens are preserved within a matrix of rock where some parts lay over other parts. In the case shown below, the skull of this pterosaur is laying across the wing bones. Without some form of scan, the skull would have to be removed to see the bones below.
An X-ray of the fossil matrix can, in many cases, reveal the bones that are concealed below the skull. X-rays of fossils depend upon variations in radio-density of the materials. If the fossil bones are replaced with different material than the surrounding matrix and have variations in density within the structures themselves, an X-ray can reveal quite a lot of detail.
Interpretation of X-rays is quite a skilful task. analysis of detail requires a great deal of knowledge about the nature of the materials that the X-rays are passing through. The analysis of this X-ray shows the interpreted wing bone positions marked.
It shows in this case, that the Wing Metacarpal has sustained a stress fracture, probably during launch for flight. This break does not have the radial signature of an impact fracture and it was probably caused by the bone at the point of fracture being too thin to sustain the stress of extreme latteral pressure. If this animal fell into the sea with one wing broken in this way, it would be unable to take off and would probably have starved to death or become a victim of small marine carnivores picking at its flesh.  There is no lower jaw associated with these remains, so that probably detached prior to fossilization.
The fossil X-ray will only show the preserved hard parts of an animal. The use is very limited, unlike this X-ray of one of my cats, which shows a good deal of soft tissue structure and variation in bone density where the bones are in their living orientation.