Underwhelming Fossil Fish of The Month: December
By Mark Carnall, on 13 December 2012
Following on from last month’s inaugural UFFoTM, I’ve received literally* thousands of emails of complaint. Here’s a selection of them:
“Underwhelming? I can see four Phd projects and an international symposium on that specimen alone”
“I was practically whelmed by it. It’ll take less than that to underwhelm me”
Professor Lord T.V. Personality
I’ve taken these comments on board, blue skied it, decided how this will facilitate us moving forward and lowered the bar accordingly. You’ll be begging me for the heady days of Brookvalia.
This month’s underwhelming fossil fish is the delightful Diplacanthus striatus. Probably. The specimen is confusingly labelled (Diplacanthus) Cleirocanthus striatus. Cleirocanthus doesn’t appear to be a valid genus at least according to any palaeobiology database, or for that matter Google. Except it may be Cheirocanthus, yes the ‘l’ looks like it could be an ‘h’. So there we have it. Possibly Diplacanthus striatus or maybe Cheirocanthus something else. This 2007 reference lists Diplacanthus striatus in the faunal list for Tynet Burn, the locality this specimen was collected from so we’ll assume that, in some circles at least, the name is still valid.
Diplacanthus is a genus of Acanthodian fish, a class of extinct fishes that disappeared in the Permian some 250 million years ago. Their thing was to evolve jaws, for which we are all grateful. Often called spiny sharks these fish weren’t sharks at all although they superficially resemble them and had a cartilaginous skeleton.
Preservation What appears in the photograph and indeed to the naked eye isn’t in fact a smear with some spikes but it is the ventral surface (the underside) of an individual, the pectoral apparatus, intermediate spines and pelvic fin can be seen. The spines which give this group of fish their common name ‘spiny shark’ are well preserved.
Research A very brief skim of the literature shows that Diplacanthus striatus isn’t much to write home about. More often than not it is a species merely mentioned as an example of an Acanthodian fish. Although interestingly the genus does occur on both sides of the Atlantic and possibly in Australia. But wait, what’s this? This specimen is part of the D.M.S. Watson fossil fish collection. Watson was the Jodrell Professor of Comparative Anatomy and Zoology at UCL and worked extensively on fossil fish and plants. The Grant Museum holds most of his palaeontological collection and this particular fossil comes from his collection. Watson literally wrote the book on Acanthodian fishes, the imaginatively titled the Acanthodan Fishes (Watson 1937) and on the section for Diplacanthus striatus he mentions
“The dozen specimens before me….”
Could our specimen be one of those dozen? There hasn’t been a Horizon exploring this, surely one of the last great mysteries of science but if there was it would conclude that unfortunately, we will never know for sure. Watson then goes on to figure a number of the other Grant Museum specimens (P299 and P300 if you are interested). Alas our specimen came so close to fame and fortune but didn’t quite make the grade. Underwhelming even for one of the only people who might potentially be interested in this lovely fossil. The species is also mentioned as a footnote in Notes on Some Little-Known Fishes from the New York Devonian (Smith 1910). Too unknown to even qualify for the high status of ‘little-known’.
In Society Diplacanthus striatus applied to be on the last series of I’m A Celebrity Get Me Out Of Here and was turned down for being too well known by the general public so underwhelming is this particular species of extinct fish.
In Society 0
The most underwhelming fossil fish in the series so far! Will it be toppled in the new year with 12 fossil fish lining up to make readers feel a bit melancholy? You’ll just have to wait and see.
Smith, B. 1910. Notes on Some Little-Known Fishes from the New York Devonian. Proceedings of the Academy of Natural Sciences of Philadelphia , Vol. 62, No. 3 (Oct. – Dec., 1910), pp. 656-663
Watson, D. M. S. 1937. The Acanthodan Fishes. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences , Vol. 228, No. 549, pp. 49-146
*+/- 1000 and rounding up to the nearest thousand.