The Discovery of a New Spiky Tailed Primitive Sauropod Announced
The discovery of a new type of sauropod dinosaur armed with spikes on its tail like a Stegosaurus has been announced after research by a joint German and Spanish team. The fossils of this particular dinosaur were found in Niger (Africa). The dinosaur is to be named Spinophosaurus nigeris (the name means spiny lizard from Niger). Niger has proved a successful hunting ground for dinosaur discoveries in recent years, famous palaeontologists such as the American Paul Sereno, from the University of Chicago, have led several expeditions to the country and recovered some amazing fossils of new types of dinosaur.
Spinophosaurus nigeris
Perhaps the most famous long-necked dinosaur associated with this particular African country is Nigersaurus, nick-named the Mesozoic vacuum cleaner because of the broad shape of this dinosaur’s muzzle. Spinophosaurus dates from much earlier in the fossil record when compared to Nigersaurus. It is a much more primitive sauropod, perhaps it is a type of cetiosaur rather than the diplodocid type of sauropod that Nigersaurus is believed to be. Fossils of Nigersaurus have been dated to the Early Cretaceous, around 110 million years ago, whilst the strata from which the fossils of Spinophosaurus were extracted are much older. Scientists estimate that this dinosaur dates from the Early to Middle Jurassic 170 million years ago (Bajocian faunal stage).
A Model of a Nigersaurus
The “Lawn Mower” sauropod. A model of Nigersaurus.
During the time of Spinophosaurus, this part of Africa was a vast river delta system in what was the huge, super-continent of Gondwanaland. Commenting on the discovery of this new dinosaur, and in reference to the primitive skeletal features and strange, spines on the tail, which looked out of place on a sauropod, Professor Ulrich Joger of the State Natural History Museum in Braunschweig (Brunswick) stated:
“At the time we thought we had found another dinosaur of the Jobaria variety”.
Jobaria
Jobaria is another type of long-necked sauropod, a titanosaur that was discovered in Tanzania by a much earlier German expedition. However, it was formerly named and described by Paul Sereno after much more fossil material was discovered in the Sahara desert in the mid 1990s. Despite dating from the Cretaceous, roughly the same time period as Nigersaurus, Jobaria retained many features of early, primitive members of the sauropod clade.
It was a detailed study of the leg bones that led the German team to conclude that they had discovered a previously unknown type of dinosaur. Jobaria is distinguished by having lighter forelimbs compared to its back legs, but this new dinosaur’s leg bones were very different indicating that this was indeed a new species.
Sauropod
The most remarkable feature of this mid-sized sauropod is the tail with its spikes sticking out at the end. Such a tail would have made a very formidable weapon, although such defences on sauropods are known to science, this is still a very remarkable discovery. The spikes on the tail resemble those on a stegosaur. Palaeontologists refer to the spiked tails of stegosaurs as “Thagomizers”. This is not a scientific name but the moniker has stuck after a Stegosaurus tail was described using this word in a Gary Larson cartoon “The Far Side”.
To read more about how this type of dinosaur tail got named: Thagomizer – How the Spikes on the Tail of a Stegosaurus got Named.
As more and more sauropod material is recovered and increasing numbers of caudal bones are found, it seems that several of these long-necked giants were armoured and had defensive weapons. Although, dermal armour and spines along the body is more closely associated with later titanosaurids such as Agustinia from South America, at least one other primitive Jurassic sauropod had an armoured tail. Fossils of Shunosaurus from the famous Dashanpu Quarry sites near Zigong in Sichuan Province, China, show that these 9-metre-long giants had a bony club on the end of the tails.
To view a models of Agustinia, Shunosaurus and other strange sauropods: Dinosaur and Prehistoric Animal Models.
Professor Joger and his team are particularly excited about the discovery of this very early type of sauropod, hoping that further examination of the skeleton will help the team to piece together the Sauropodomorpha family tree.
He commented
“The discovery is of particular importance as this dinosaur sits at the top of the sauropod genealogical tree. With this find, Africa moves to the centre of dinosaur research. But Africa is a politically unstable continent, often making digs there particularly difficult. There was a far reaching river complex in the area, so the animals we found there were surrounded by an overwhelming presence of life”.
Excavation Project
The excavation project was undertaken between 2005 and 2008, mostly in the Republic of Niger. Local nomadic people showed the German scientists where the leg bones could be found, lying exposed as they were. The dig site initially revealed two skeletons, to be taken back to Germany for preparation, before the site was shut down.
Unfortunately for the Germans, it was a Spanish led group that first got hold of one of the skeletons of this newly discovered long-necked dinosaur after hearing about the exposed leg bones weathering out on the rock surface. Since then, researchers from the two countries have been working together on the specimen in Bonn and Brunswick.
Sauropod Dinosaur
However, Professor Joger revealed that his team had discovered a third fossil specimen, not a sauropod but a meat-eating dinosaur described as a “raptor”. This specimen was found in same area just a few hundred metres from Spinophosaurus, and it too, is probably a new genus. If this new carnivorous dinosaur does turn out to be a raptor (dromaeosaurid type dinosaur), then this would be a very significant discovery indeed. To date such dinosaurs are associated with the Northern Hemisphere and not known from this part of Africa.
As a thank you for helping with the discovery of Spinophosaurus and the subsequent excavation work, the German scientists have worked with a charity to establish a school for the local tribe and provided many thousands of school books. Indeed, representatives from Niger are going to be present when the restored fossils are put on display in the State Natural History Museum of Braunschweig next month.
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