Roger’s dinosaurs

Who doesn’t love dinosaurs? Well me, actually. I’ve nothing against them as individual fossils, but I feel that as a group they grab far too much of the limelight from other more humble fossils. These other fossils, such as ammonites or crinoids, two groups that I have worked on (I even have had two species of fossil crinoid named after me!), are just as deserving of our attention but I will make an exception for local, ‘home-grown’, dinosaurs since we have so few of them. Indeed, we are very lucky to have any at all!

Image: Dinosaurs near Coolaney, Co. Sligo. With thanks to Magnumlady Blog for permission to use this image.
Dinosaurs near Coolaney, Co. Sligo. With thanks to Magnumlady Blog for permission to use this image.

Dinosaurs appeared in the late Triassic Period, about 230 million years ago, and thrived through the Jurassic and Cretaceous periods to become extinct around 66 million years ago (except for the ones with feathers, that we now call birds); a period of about 165 million years in total. Unfortunately, Ireland has very little rock of this age; in the south nearly all of the rock (more than 99.999%) is just too old to have dinosaurs. In the north it is only a little better, with most rock at the surface either too old or too young to contain dinosaur fossils. Perhaps just 1% of the rock found at the surface of Northern Ireland is the right age, but the difficulties do not end there. We do not have a full 165 million-year record of rock for the ‘Age of the Dinosaurs’ – half of it is missing! There is a gap of at least 80 million years in the middle, with no rocks at all from around 182 million years to 100 million years ago. Either these rocks were never deposited in the first place or they were eroded away many millions of years ago. That is potentially 80 million years worth of dinosaurs that we are never going to find even if they had once been here.

But it gets worse. Even the rocks we do have that are the right age were deposited in the wrong place. Dinosaurs lived on land, generally in well-vegetated places where there was plenty of food. Dinosaur fossils are most commonly found where they were buried quickly after they died, such as in ancient river sandstones. All of the ‘right-age’ rocks that we have were deposited either in an arid desert, where no fossils at all have been preserved, or on the sea bed far from land, where we find plenty of fossils but only of animals that were living there.

Image: The wrong sort of rocks, Caranure, Antrim Coast Road. The red muds at the bottom are the right age for some of the earliest dinosaurs, but were deposited in an arid desert. 
The white limestone above is the right age for some of the last of the dinosaurs, but was deposited far out at sea. The black basalt layers at the top are volcanic lava flows so contain no fossils, and they are several million years too young for dinosaurs anyway.
The wrong sort of rocks, Caranure, Antrim Coast Road. The red muds at the bottom are the right age for some of the earliest dinosaurs, but were deposited in an arid desert. The white limestone above is the right age for some of the last of the dinosaurs, but was deposited far out at sea. The black basalt layers at the top are volcanic lava flows so contain no fossils, and they are several million years too young for dinosaurs anyway.

Finding an Irish dinosaur might seem a hopeless task, but step up to the mark Roger Byrne. Roger, a school teacher from Jordanstown, on the north shore of Belfast Lough, was an enthusiastic fossil collector. He amassed a considerable collection, mainly from around the shores of Islandmagee and Larne Lough, and donated many specimens to the museum until his untimely death in 2007 at the age of just 64.

Among the fossils that Roger collected were several strange bones found in Jurassic clays, around 200 million years old, near The Gobbins. One of these was identified as part of a dinosaur bone by the late Robin Reid, a geology lecturer at Queen’s University Belfast, and its discovery was reported in the local press in 1989. I arrived at the Ulster Museum late in 1996 and met Roger on several occasions. A few years later he donated several more fossil bones, two of which both Roger and I suspected were from dinosaurs. One was obviously part of a leg bone, like the fragment identified by Robin Reid, but the other was a small flat pentagonal object. We thought it might be a bony plate from an armoured dinosaur called Scelidosaurus, with the other two bones also from this dinosaur, but there was a problem. Dinosaur experts suggested I show this strange pentagonal ‘bone’ to turtle experts, and the turtle boffins said I should show it to the dinosaur guys. None of them seemed to want much to do with it.

Image: Roger Byrne in the Burren, Co Clare, in 2003.
Roger Byrne in the Burren, Co Clare, in 2003.

In December 2008 I took the bones across to the Natural History Museum in London and spent a day comparing them with some of the dinosaur bones in their vast collections. I would not claim to be any sort of expert on dinosaurs, but one of the Irish bones seemed to bear a close resemblance to the upper part of a femur (upper leg bone) of an armoured dinosaur called Scelidosaurus harrisoni. This dinosaur is quite well known from several near complete skeletons found in Dorset (there is a plaster cast of one of these skeletons on the wall of the Fossils and Evolution gallery in the Ulster Museum), where they have been found in Lower Jurassic clays very similar in age to those on Islandmagee. The other bone was the wrong shape to be from Scelidosaurus and the closest match that I could find was the upper part of a much larger tibia (lower leg bone) of Megalosaurus bucklandi, a two-legged meat-eater found in the Middle Jurassic of Oxfordshire. But that little pentagonal ‘bone’ still remained a bit of a mystery.

Image: The Antrim bone fragments compared with dinosaur bones at the Natural History Museum in London. Scelidosaurus on the left and Megalosaurus on the right.
The Antrim bone fragments compared with dinosaur bones at the Natural History Museum in London. Scelidosaurus on the left and Megalosaurus on the right.

That is where things remained for a few years; I had a fair idea of the types of dinosaur from which our bones came, but I lacked the level of expertise needed to describe and interpret them for an academic journal.

Roll on to the summer of 2019 and I took these three bones to friend and dinosaur expert Professor Dave Martill at Portsmouth University. Dave and his colleague Robert ‘Rab’ Smyth, originally from Ballymoney, broadly confirmed what I had suspected but added a considerable level of authority that hitherto had been lacking, and together we wrote a paper describing and interpreting these fossils. They concluded that the original bone was indeed the top of a femur, probably from Scelidosaurus, and the other bone was part of a theropod tibia perhaps related to a dinosaur called Sarcosaurus, an older cousin of the Megalosaurus that I had seen at the Natural History Museum.

Image: The two bone fragments (theropod tibia on the left and Scelidosaurus femur on the right) with Dr Mike Simms, Senior Curator of Natural Sciences at NMNI.
The two bone fragments (theropod tibia on the left and Scelidosaurus femur on the right) with Dr Mike Simms, Senior Curator of Natural Sciences at NMNI.

By a peculiar twist of fate (that’s something for a future blog) renowned wildlife artist Julian Friers had produced a series of paintings of some of Ireland’s ‘Lost Monsters’ (Giant Deer, Mammoth and the like), to be included in the Dippy on Tour exhibition in the Ulster Museum in 2018. Julian and I talked about Roger’s dinosaurs and, before I knew it, he had produced these magnificent reconstructions of what they had perhaps looked like in life.

Reconstruction in life of Sarcosaurus. Artworks by Julian Friers as part of the ‘Lost Monsters’ series
Reconstruction in life of Sarcosaurus. Artworks by Julian Friers as part of the ‘Lost Monsters’ series
Reconstruction in life of Scelidosaurus. Artworks by Julian Friers as part of the ‘Lost Monsters’ series
Reconstruction in life of Scelidosaurus. Artworks by Julian Friers as part of the ‘Lost Monsters’ series

Dave and Rab had only a week to work on the bones directly. I dare not risk such valuable museum objects to the post so, while holidaying on the Isle of Wight in the summer of 2019, I delivered them to Portsmouth via the hovercraft and returned to collect them a week later. But even after I had whisked the bones back to Belfast, Dave and Rab were able to continue their work using ‘virtual’ copies of them. These were prepared through the efforts of Dr Patrick Collins, of Queen’s University Belfast, who created very high-resolution 3D scans and photographs of the bones from which they could even print out 3D copies.

Although Roger, sadly, was no longer with us we included in the paper his beautiful sketches of the bones (and that funny wee pentagonal thing).

Image: Some of Roger’s beautifully drawn sketches of the two bones. The top four (e, f, k, l) are different views of the Sarcosaurus tibia, and the bottom two (d, e) are the Scelidosaurus femur.
Some of Roger’s beautifully drawn sketches of the two bones. The top four (e, f, k, l) are different views of the Sarcosaurus tibia, and the bottom two (d, e) are the Scelidosaurus femur.

But what about that funny pentagonal ‘bone’? As soon as Dave saw it he questioned that it was even a bone at all. Looking at it closely, I realised he was right. It was actually a small piece of basalt, countless pebbles of which lie scattered on the beaches of Islandmagee. Who would have thought, in the land of the Giant's Causeway, that such a remarkably regular fragment of basalt could turn up on an Antrim beach? The lesson to be learned here is that I was perhaps too influenced by the remarkably regular shape of this object and by its discovery on the same beach where a dinosaur bone, tentatively assigned to Scelidosaurus, had been found.

Image:

So, are these bones actually that special? Obviously, as the only dinosaur bones ever found anywhere in Ireland, North or south, they are special to us, and we are extraordinarily lucky to have even these. It is very unusual to find dinosaur bones in rocks deposited on the Jurassic sea bed, so they must have come from animals that were swept out to sea, either dead or alive, to end up on the sea bed among all the marine fossils we would normally expect to find there.

But these bones are rather special in in the greater scheme of things too. Not many dinosaurs are known from this period of time right at the start of the Jurassic, around 200 million years ago, so these two bones, fragmentary though they are, tell us something about Early Jurassic dinosaur diversity right out on the western edge of Europe. One of them perhaps also adds to our understanding of a long-standing enigma. An almost complete skeleton of Scelidosaurus was found in the Lower Jurassic marine clays of the Dorset coast back in the mid-19th Century, and several more skeletons and many more bones have been found there since, yet evidence of other types of dinosaur in these marine clays is vanishingly rare. There must have been something about Scelidosaurus that made it vulnerable to being swept out to sea. Perhaps they preferred coastal habitats or maybe, as Dave Martill has suggested, they even ate seaweed just as Marine Iguanas on the Galapagos Islands do today. We can’t know for sure, but our little bone fragment from Islandmagee adds to the bigger picture.

Image: The title page of the paper.
The title page of the paper.