Sunday, August 23, 2015

Megalosaurus: Beast of the Week

This week we will be looking at the dinosaur that started it all. (sort of)  Say hello to the mighty Megalosaurus!  Megalosaurus bucklandii was a meat-eating dinosaur that lived in what is now Oxfordshire, England, during the middle Jurassic Period, about 166 million years ago.  From snout to tail Megalosaurus is estimated to have been about thirty feet long but since a complete skeleton has yet to be found, this number is subject to change.  The genus name, Megalosaurus, translates to "Big lizard/reptile" because at the time of its discovery, its bones were thought to have belonged to a large lizard and not a dinosaur. (Remember at that time nobody knew what an actual dinosaur was yet)  Despite the fact that we know dinosaurs aren't lizards now, many are still given "saurus" as part of their names anyway.  The species name is in honor of Professor William Buckland, who studied much of Megalosaurus' bones. 

Megalosaurus reconstruction by Christopher DiPiazza

Despite only being known from fragmented remains, consisting of a leg, a hip, some vertebrae, the tip of the snout, and a few teeth, Megalosaurus is a very monumental find because it was the first dinosaur officially named by science.  (Megalosaurus was NOT the first dinosaur fossil ever discovered by humans, however.  People have been digging up prehistoric dinosaur bones for thousands of years.  They just were not calling them dinosaurs.  It is likely dinosaur, and other prehistoric animals, may have been the inspirations for some of the monsters seen and told about from the mythologies and folklores around the world.)  Megalosaurus was, however, the first dinosaur to be formally studied and officially referred to as a dinosaur.  It stated way back in 1676 when a piece of a leg bone was uncovered that baffled everyone.  It was much too large to belong to any animal native to England at the time.  At first it was thought to belong to a war elephant from ancient Rome and was later re-identified as belonging to a giant human, like the ones described in the Bible. (which have since been confirmed never existed)  This bone fragment was even given a scientific genus and species name, Scrotum humanum, which means exactly what it sounds like; "human scrotum".  It makes me wonder if the scientists who named the fossil were early incarnates of Beavis and Butthead.
lol
Much later, in 1815, more giant bones from a mysterious creature were discovered in southern England.  They were sort of a mystery to any scientist who looked at them for a few years because they were so unlike anything anyone had ever seen before.  Then in 1818, they were finally identified as belonging to some sort of enormous reptile.  After studying these bones extensively for the next several years, it was officially named Megalosaurus at the Geological Society of London in 1824.  It was concluded that the original bone fragment, which was named Scrotum humanum, was also from Megalosaurus.  However, the original name was ditched in preference for the more informative one.  (and all the perverts cried.)  

Megalosaurus bones on display at the Oxford University Museum of Natural History.

 In the 1840s, life-sized statues of Megalosaurus and several other species of prehistoric animals were erected in the gardens of the Crystal Palace in England.  The actual palace has been destroyed by a fire, but the grounds where the statues are still remain in the form of a park now.  Back then, since scientists knew much less about dinosaurs, Megalosaurus was represented as a large, lizard-like creature.  We now know it would have looked very different thanks to the many discoveries that have been made since.


Megalosaurus statue at the Crystal Palace gardens.  At the time of its construction dinosaurs were believed to have been much more lizard-like.

When alive, Megalosaurus would have walked on its hind legs as an obligate biped.  (Meaning it could not have walked on all fours even if it wanted to.) Although the front limbs were never found, it is likely, judging by other related theropod dinosaurs, Megalosaurus had three digits on each hand with a hook-shaped claw on the tip of each finger.  Its teeth were sharp and somewhat laterally compressed to better slash the flesh of its prey.  They also had small serrations for cutting meat while feeding.  Although not much of Megalosaurus' anatomy is known, there have been other dinosaurs that share similarities with what we do have of Megalosaurus, like Torvosaurus from North America, which helps us guess what Megalosaurus may have looked like and also what it was related to.  Because Megalosaurus was discovered first, the entire family which includes it and its relatives like, Torvosaurus, is called megalosauridae.  It is also believed that megalosaurids share a relatively recent common ancestor with spinosaurids.

One more fun fact.  The show, Dinosaurs, from the early nineties on the ABC channel here in America, focused around an anthropomorphic family of dinosaurs.  The members of this family were mentioned as being Megalosaurus several times during the series.  (Lots of artistic liberties were taken.)

I know the daughter has a frill but they were still Megalosaurus apparently.
That is all for this week!  As always feel free to comment below or on our facebook page!

References

Benson, R.B.J.; Barrett, P.M.; Powell, H.P., & Norman, D.B. (2008). "The taxonomic status of Megalosaurus bucklandii (Dinosauria, Theropoda) from the Middle Jurassic of Oxfordshire, UK". Palaeontology 51 (2): 419–424.

Benson, R.B.J. (2010). "A description of Megalosaurus bucklandii (Dinosauria: Theropoda) from the Bathonian of the UK and the relationships of Middle Jurassic theropods". Zoological Journal of the Linnean Society 158 (4): 882. 

Buckland, W. (1824). "Notice on the Megalosaurus or great Fossil Lizard of Stonesfield". Transactions of the Geological Society of London. 2 1 (2): 390–396. 

Carrano, M.T.; Benson, R.B.J.; & Sampson, S.D. (2012). "The phylogeny of Tetanurae (Dinosauria: Theropoda)".Journal of Systematic Palaeontology 10 (2): 211–300.

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