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.

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