(Large tailed lizard).
Named By: Harry Govier Seeley - 1876.
Classification: Chordata, Reptilia, Dinosauria, Saurischia, Sauropodomorpha, Sauropoda, Titanosauriformes.
Species: M. Semnus (type).
Size: Estimates range between 10 and 12 meters long, but these figures are highly speculative since only remains of the tail are known.
Known locations: England, Cambridge - Cambridge Greensand.
Time period: Aptian to Barremian of the Cretaceous.
Fossil representation: Two sets of caudal (tail) vertebrae.
The problem with the genus Macrurosaurus is that it is only represented by two sets of caudal vertebrae that were both found separately and then later added together. This combined with the lack of other fossil remains for the genus mean that some palaeontologist consider the genus to be dubious because it would be near impossible to definitively attribute further remains to the genus. This is also why it is impossible to establish the length of the full dinosaur since only parts of the tail are known, and these allow for a length of four and half meters. For example, no one can say with absolute certainty how long the neck was, or even what other genera would be a good stand in for the missing body parts to give us an idea, there are simply too many variables to allow for an accurate figure. The only things that can be said for Macrurosaurus is that as a sauropod it likely had a long neck and it ate plants, since these are common traits of all known sauropods.
- On Macrurosaurus semnus (Seeley), a long tailed animal with procoelous vertebrae from the Cambridge Upper Greensand, Harry Govier Seeley - 1876.