Allosaurus jimmadseni a New Allosaurus species and Allosaurus coloring pages

This is a free coloring pages blog.  I am also (as a retired science teacher) posting some lessons I created when I was a Jr. High Science Teacher.  There are over 850 free coloring pages on this blog. 

Just click on the buttons up top to get to the printable pages.  No fees and no ads on this site. 

Allosaurus jimmadseni

Allosaurus is a very well known Genus of dinosaurs.  The most common is Allosaurus fragilis.  

But now there is a newly named dinosaur that is a new species of Allosaurus.  It was named after Jim Madsen, the paleontologist who found this fossilized skeleton.  The bones were found in the 1990s but it took a long time to be sure that this was truly a new species.  

At first they could not find the skull.  But they went back with Geiger counters, I guess, because the skull was found because it was radioactive.  They actually only found half of the skull but it was a perfect half.  It was divided down the exact middle... so they know what the entire skull looked like.  

On the skull was evidence of a crest over each eye and stretching to near the end of the snout.  This dinosaur was not as big as its more well known cousin.  But it was clearly still a powerful predator.  It had a little narrower snout and was more like 26 feet long instead of 39 feet long like Allosaurus fragilis.  This new Allosaur. Allosaurus jimmadseni, weighed about 4000 lbs or 1.8 metric tons. 

This new Allosaur lived about 5000 years before the more well known North American species.  frgilis.  It is quite likely that Allosaurus fagilis evolved from Allosaurus jimmadseni.  Both species lived in the late Jurassic Period. . . but Allosaurus jimmadseni lived first so it is probably the ancestor species.  It is even possible that some of the Allosaurus jimmadseni were driven to extinction by their new cousin.  This is because possible geographic isolation may have led to speciation and then the new and bigger species with a stronger bite would drive their parent species to extinction.   

NOTE:  This drawing, in printable form, can be found by clicking on the category buttons up top labeled . . . . . ..All Printables . . . .. . . or . . . . .  Paleontology.    This new drawing will be closer to the bottom of the list.  Have fun coloring!   One final thing, I am posting a drawing of Allosaurus fragilis from a previous post.  I am also posting a drawing of Dilophosaurus, since the crests on the snout of Allosaurus jimmadseni look a bit like Dilophosaurus crests.  I also want to admit that dinosaur scales were certainly much smaller.  I know, I know, both Allosaurus drawings look like I  was drawing dragon scales.  

Allosaurus fragilis close up

(Notice that the crest is just over the eyes.)

  (This is an older drawing, done just a couple of weeks ago.)

Dilophosaurus emerges from the Forest

(This is an older drawing, done some time ago.)