Sunday, December 07, 2008

Dino World

I am about to give a lecture on dinosaur palaeobiogeography here in Bristol and was tinkering with some data from the Paleobiology database (PBDB) and thought I'd upload the above image for your delectation.

The PBDB recently added two new data fields: palaeolatitude and palaeolongitude. I'm not entirely sure how these are done, but basically any fossil occurrence that has latitude and longitude data added also gets a palaeolatitude and palaeolongitude. Whilst preparing my talk I thought I'd stick up a world map with all of the dinosaur occurrences included on it, but decided to plot out the original positions too.

The above graph shows the modern location of each fossil locality (a light blue circle), it's original position (dark blue circle) and, so you can see how these link up, a red line connecting the two. The resulting image thus shows the 'tracks' along which the modern continents moved. (FYI: the graph was produced in R using the 'maps' library).

There are problems with this plot, however. There are three lines which are quite long and cross over other lines quite obtusely. The upper one of these (leading from the northeast of Russia to somewhere North of the Bering Strait is likely an artefact of drawing the plot on this particular projection. (In reality it should cross the Date Line and not wrap around the Earth in a whole different direction). The two others (the very southern line and the Japan-to-Atlantic line) are a bit harder to explain, but likely they are the result of some kind of error.

Still, I'm quite happy with it.

3 comments:

Manabu "Mambo-Bob" Sakamoto said...

Wow...this is really cool...you can pretty much see the opening of the south Atlantic and the movement of India

John said...

Isn't that southern line also a product of the projection? From the looks of it, it would be much shorter if you plotted it on a globe. No idea what's going on with that Japan-Africa line, though.

Malacoda said...

I think the Southern line is wrong, because I'm pretty sure nobody has found a dino in that location. It could have been a typo in a data entry error or summat, but I think all the Antarctic dinos are from the Transantarctic mountains.

Japan-Africa is a puzzler though. Haven't tracked down the individual entry yet.

About Me

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Currently I am founding member, president elect and entire membership of SWEMP (the Society of Wonky-Eyed Macroevolutionary Palaeobiologists). In my spare time I get paid to do research on very dead organisms and think about the really big questions in life, such as: What is the ultimate nature of reality? Why is there no room for free will in science? and What are the implications of having a wardrobe that consists entirely of hotpants?