Skip to main content

Ultrasaurus and Ultrasauros

This is an ancient topic, but I was just thinking about it the other day.

Do you remember that whole thing about Ultrasaurus?

In 1979, James Jensen of Brigham Young University found what he believed to be the largest sauropod ever. The press went mad and widely publicised the dinosaur under the name Ultrasaurus. I remember as a kid that Ultrasaurus (along with Supersaurus) was always depicted as a huge brachiosaur dwarfing even Brachiosaurus.

However, it took another 6 years before Jensen finally published his findings. By then, a Korean palaeontologist, Haang Mook Kim, had already named a sauropod with the name Ultrasaurus because he thought it belonged to the same genus that Jensen had found. But it turned out that Kim's Ultrasaurus was something different, and when Jensen wanted to use Ultrasaurus, his first preference, he couldn't because it was 'preoccupied'. So he instead named his dinosaur Ultrasauros with an 'o'.

Funnily enough, Kim's Ultrasaurus later became a nomun dubium or a dubious name because there wasn't enough information to assign it to any dinosaur family. Jensen's Ultrasauros had also become a junior synonym of Supersaurus because it turned out that the type of Ultrasauros was in fact a chimera comprised of bones from Supersaurus and a very large brachiosaur. Since Supersaurus was named earlier, Ultrasauros unfortunately had no right to be a recognised genus name.

So despite the huge confusion they caused, both Ultrasaurus and Ultrasauros are now invalid taxa.

Originally posted on DinoBase

Comments

alissaissa said…
grest, now i have to do a science report on a dinosaur that doesnt exist now.......
Well, I'm sure you can do a report on how it doesn't exist and the confusion behind naming dinosaurs...?

Popular posts from this blog

The difference between Lion and Tiger skulls

A quick divergence from my usual dinosaurs, and I shall talk about big cats today. This is because to my greatest delight, I had discovered today a wonderful book. It is called The Felidæ of Rancho La Brea (Merriam and Stock 1932, Carnegie Institution of Washington publication, no. 422). As the title suggests it goes into details of felids from the Rancho La Brea, in particular Smilodon californicus (probably synonymous with S. fatalis ), but also the American Cave Lion, Panthera atrox . The book is full of detailed descriptions, numerous measurements and beautiful figures. However, what really got me excited was, in their description and comparative anatomy of P. atrox , Merriam and Stock (1932) provide identification criteria for the Lion and Tiger, a translation of the one devised by the French palaeontologist Marcelin Boule in 1906. I have forever been looking for a set of rules for identifying lions and tigers and ultimately had to come up with a set of my own with a lot of help

R for beginners and intermediate users 3: plotting with colours

For my third post on my R tutorials for beginners and intermediate users, I shall finally touch on the subject matter that prompted me to start these tutorials - plotting with group structures in colour. If you are familiar with R, then you may have noticed that assigning group structure is not all that straightforward. You can have a dataset that may have a column specifically for group structure such as this: B0 B1 B2 Family Acrocanthosaurus 0.308 -0.00329 3.28E-05 Allosauroidea Allosaurus 0.302 -0.00285 2.04E-05 Allosauroidea Archaeopteryx 0.142 -0.000871 2.98E-06 Aves Bambiraptor 0.182 -0.00161 1.10E-05 Dromaeosauridae Baryonychid 0.189 -0.00238 2.20E-05 Basal_Tetanurae Carcharodontosaurus 0.369 -0.00502 5.82E-05 Allosauroidea Carnotaurus 0.312 -0.00324 2.94E-05 Neoceratosauria Ceratosaurus 0.377 -0.00522 6.07E-05 Neoceratosauria Citipati 0.278 -0.00119 5.08E-06 Ovir

Hind limb proportions do not support the validity of Nanotyrannus

While it was not the main focus of their paper, Persons and Currie (2016) , in a recent paper in Scientific Reports hinted at the possibility of Nanotyrannus lancensis being a valid taxon distinct from Tyrannosaurus rex , using deviations from a regression model of lower leg length on femur length. Similar to encephalisation quotients , Persons and Currie devised a score (cursorial-limb-proportion; CLP) based on the difference between the observed lower leg length and the predicted lower leg length (from a regression model) expressed as a percentage of the observed value. The idea behind this is pretty simple in that if the observed lower leg length value is higher than that predicted for its size (femur length), then that taxon gets a high CLP score. I don't particularly like this sort of data characterisation (a straightforward regression [albeit with phylogeny, e.g. pGLS] would do the job well), but nonetheless, Persons and Currie found that when applied to Nanotyrannus , it