Friday 21 September 2012

Chirotherium footprint in 3D

Here's a 360-degree animated view of a superb Chirotherium footprint cast I recorded on my recent trip to Manchester Museum's ichnology collection.

Notice the prominent claw marks and well-preserved nodes on each digit. Digit V is present but not quite as well preserved, and shows this is a left foot print. What is especially interesting about this particular print is the length of the footprint; aside from the impressions of the digits which are often seen in specimens of this ichnotaxa, there is a well-defined u-shaped bulge, the hindmost margin of which is approximately 240mm from the tip of digit III. Could this represent the heel of the foot? Well, I'm not so sure and I hope to have a closer look at this print when time allows. The distance to the fracture is around 169mm.

The techniques used to record this fossil (and other digital methodologies) will be discussed in talks and taught in workshops at DigitalFossil 2012 in Berlin, which starts on Sunday. It will be well worth visit if you're interested in the digital techniques currently being used and under development and their applications in palaeontology and ichnology.

Sunday 9 September 2012

Tracks from the Triassic: Isochirotherium in 3D

I spent a fruitful morning in the ichnology collections at Manchester Museum last week, where I had gone to look at some examples of invertebrate trace fossils that can be found in the local area and which might be a basis for future research. I was also looking at local vertebrate footprints from the Triassic and whilst there took the opportunity to photograph some of dinosaur footprints housed in the collection.

Here is a 360-degree rotation of a particularly fine print of Isochirotherium lomasi, an enigmatic archosaur known only from its tracks and recorded using photogrammetry during a previous visit. The museum has a fine collection of these prints and this particular one is on public display in the fossil gallery and comes from a site on the Wirral in north-west England, an area which has produced many tracks over the years. This is a left print as the 'thumb' is actually the outermost digit of the pes (or manus), and is very similar to the ichnogenus Chirotheruim, a fact that led no less an anatomist than Richard Owen to conclude the thumb was digit I and thus Chirotherium walked cross-legged, and it took until 1925 until Wilfred Soergel established that this 'thumb' was indeed the outer digit.

Many thanks to David Gelsthorpe, Curator of Earth Science Collections (@paleomanchesterand Kate for their invaluable help whilst I was there; they made me feel very welcome and I look forward to going back. More goodness from the excellent Manchester Museum collections to come.