By Mark Carnall, on 31 March 2014
I’ve sectioned the otoliths of 2014 and determined that it is March and there’s just enough time for this month’s underwhelming fossil fish of the month.
For those of you new to the series, all of which can be found in this link, here’s how I’d introduce the TV series, walking slowly through a museum storeroom, gesticulating wildly and oddly emphasizing words (in caps below) in the way that you only see in science documentaries.
“Join me, MarK CArnall as I eXplore the aMazing WOrld of fossil fish. IN this SERIES we look at the AMAZING, comPLEX worLd of the unsung, unINspiring fossil fIsh that FILL the storeROOMs of the WORLD’s aMazing museums. We’ll look at the WEIrd, the WONderful and the aMazing fossil fish to dRive up the wOrld’s gLObal fishteracy. ONE fossil fish at a time.”
CUT TO SHOT OF MARK PEERING AT A FOSSIL FISH THEN LOOKING OFF TO THE HORIZON.
I’ve got a real doozy of a fish for you this month. Prepare to be disappointed. Steel yourself for disdain. Turn that apathy up to 11.
Cast your eyeholes over this month’s underwhelming fossil fish of the month. In a world exclusive this is the first cast of a fossil fish to feature in this series. The ratings were creeping too high and the executives decided that the only thing more underwhelming than a fossil fish was an underwhelming cast of an underwhelming fossil fish.
Not much to look at is it? In fact, a number of the Grant Museum team have been stopped in their tracks with how underwhelming this cast is whilst it was out on my desk as I was writing this. But no matter how much you squint your eyes, tilt your head or even turn it upside down it’s hard to discern exactly what it is we’re looking at.
Fortunately, the old gods of museum documentation have smiled upon us as the life story of this specimen is handily written on the back of it.
As the inscription explains, this is a cast of the underside of the large central plate of Psammosteus taylori. The original specimen was in the Edinburgh Museum of Science and Art (now National Museums Scotland) but sadly I couldn’t find the specimen on their online catalogue. It was presented to ‘somebody’ in 1900 and at some point ended up at Imperial College London and then subsequently came to the Grant Museum when the Imperial collections came here in the 1980s. Imperial College London wasn’t formally established until 1907 so I’m going to see whether National Museums Scotland has records of who and where this cast was presented to.
Researching Psammosteus taylori has been tricky as it doesn’t appear to be a valid species. I found it as a synonym for Psammosteus megalopteryx but this isn’t an accepted species either according to some authorities. The literature on these species is rather thin on the ground. Assuming that this is indeed a cast of a large central plate from an animal in the genus Psammosteus, these fish belong to a group of extinct jawless fish called Heterostraci. These large plates or shields, illustrated in a related species in this rather wonderfully coloured reconstruction here link, gave heterostracans a rather odd appearance. Psammosteus and related genera were some of the largest heterostracans to have ever lived as this hefty head shield demonstrates nicely. Sadly this wonderful group went extinct at the end of the Devonian period, with Psammosteus and it’s relatives being one of the last lineages of this bizarre group to disappear.
Preservation This is obviously a cast but it appears that the original doesn’t seem to have been in particularly spectacular condition either. What’s bizarre about this, if the inscription is to be believed, is that it’s a cast of the underside of the head shield which is presumably the least interesting bit. It appears to have been meticulously painted to resemble original specimen which is a bit of a head scratcher. Why was so much effort put into making, colouring and gifting this cast for a species which according to my initial research seems to have vanished almost as quickly as it was described? SEAMLESS SEGUE INTO RESEARCH
Research Using highly sophisticated and advanced research techniques which may involve codes, cyphers and the services of an American multinational corporation specializing in Internet-related services I’ve not been able to dredge up much about this species, despite this specimen being the only underwhelming fossil fish so far to have a reference written on it. According the the inscription, the original specimen was figured in “Extinct Vertebrata of the Moray Firth Area”. I’ve not been able to access this rather key reference but it seems to be one of the few times it’s ever been figured. I did find part of a short paper in 1911 by palaeontologist and fossil fish superstar Arthur Smith Woodward which mentions the original specimen given to the Royal Scottish Museum, as it was then, later to become National Museums Scotland (Woodward 1911). The only other reference I found was a 1936 paper still using the combination Psammosteus taylori making the briefest reference to such a shield (Bryant 1936).
In Society You’ll be unsurprised to learn that Psammosteus is very much a ‘Mr Cellophane’ taxon with no measurable impact on society at all. As a curator a lot of my work involves working with objects and specimens and it’s very difficult sometimes not to personify the objects I work with. In this particular case I do find myself feeling a bit sorry for this specimen. First of all it’s a cast, it’s not ‘even’ real. Secondly it’s a pretty underwhelming cast of a fossil fish that for want of a better phrase has fallen by the wayside. So uninteresting is the species that it may or may not exist. It’s a Schrodinger’s species but nobody is interested in even opening the box. I’m getting teary here. Hopefully this post will help to put poor Psammosteus taylori, or whatever the actual valid name may be, on the map.
In Society 0
Woodward, A. S., 1911: On the Upper Devonian Ostracoderm, Psammosteus taylori. Annals and Magazine of Natural History Series 8: 8 649-652
Mark Carnall is the Curator of the Grant Museum of Zoology