Friday mystery object #71 answer

Part the first:

On Thursday I accidentally posted the Friday mystery object for a few moments and in that tiny window of opportunity SmallCasserole managed to correctly identify this organism:

As soon as it was posted properly this object also proved no challenge to several of the other regulars, with David Hone, CopilasDenis, David Craven and Dave Godfrey all spotting that it was a graptolite. Moreover, David Craven managed to correctly identify the species as Didymograptus murchisoni (Beck, 1839). This particular specimen is Ordovician, more precisely it’s 472-464 million years old and it’s from Wales – specifically from Carregwiber, Radnor (grid reference SO085588).

Graptolites were an odd group of animals that went extinct about 380 million years ago, in the Carboniferous. They shared similarities with modern pterobranchs, being filter feeding zooids living in colonies. Unlike the pterobranchs, there were plentiful planktonic forms of graptolite floating around in the ancient oceans, so they were widely distributed and as a result their fossils make useful biostratigraphic markers. The preservation of these fossils makes them look just like they’ve been drawn on the rock hence the name ‘graptolite’, which pretty much means ‘written on rock’ –  so they could be considered to be nature’s graffiti.

Part the second:

In view of the confusion caused by my inability to press ‘Save Draft’ rather than ‘Publish’, I decided to provide an additional mystery object (there is no real logic there – I’ve been busy with writing interpretation text for specimens going on display and was a bit distracted when I made this decision). The extra object was this:

I know it looks a bit like Humpty-Dumpty after the wall incident, but it hasn’t been broken. It’s the skull of an Asian Elephant Elephas maximus Linnaeus, 1758 as correctly identified by CopilasDenis. More specifically, it’s the skull of a neonate (new born) Elephant, as spotted by David Craven, Dave Godfrey and Jake. The reason it looks broken is due to the fact that the bones are unfused. This is pretty standard for young animals, since the bone needs expansion room to grow.

In life there would have been cartilage and connective tissues between the bony plates of the skull and as the animal grew the cartilage would have become ossified (bony) and the sections of bone would eventually have fused together along sutures between the adjacent plates.

The teeth look a bit odd for an elephant, but that’s partly because they are the ‘milk teeth’ or deciduous dentition and partly because they didn’t get enough use to become worn down, since this individual died not long after it was born.

2 thoughts on “Friday mystery object #71 answer

  1. I spent a lot of time collecting graptolites in Wales when doing Undergrad geology, so I’d have been disappointed to get that wrong.
    I do love them, for being the only fossil easily faked with an HB pencil and a piece of slate! Fascinating things, very hard to explain what they were to people.

    The elephant skull was fascinating, always wondered what they looked like. The teeth nearly threw me, they didn’t quite look right.

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