Aquilops: Beast

Today we will be learning about a dinosaur that sets the record for oldest ceratopsian (beaks and frills) ever discovered in North America!  Check out Aquilops americanus!  

Aquilops was a plant-eating dinosaur that lived in what is now Montana, USA, during the Early Cretaceous Period, between 104 and 115 million years ago.  Teeth and a few isolated bones of what appear to be the same species (for now) have also been found as far east as Maryland.  It was tiny, only two feet long from beak to tail, but was a very early member of the ceratopsian group of dinosaurs, which includes the very famous, Triceratops.  The genus name, Aquilops, translates to “eagle face” in reference to the dinosaur’s hooked beak.  The species name, americanus, is because it lived...in America.

Aquilops life reconstruction by Christopher DiPiazza.

 Even though Aquilopsis only known from a single skull, it is a very important find that provides a lot of information about dinosaur evolution.  Never before has a ceratopsian fossil as old as Aquilops been discovered in North America.  The next oldest in the continent is Zuniceratops, at 90 million years old.  Aquilops proves that ceratopsian dinosaurs migrated to North America from Asia (where Yinlong, the oldest known member of the group was found) earlier than previously thought.  

Skull of Aquilops americanus.  Photo provided by Andrew Farke.

Aquilops has a few interesting features about it physically.  Most noticeable is the small bump (called a boss) that appears at the front of its beak.  In life, when the beak was covered in a layer of keratin, there may have been a point there, like a horn, or maybe extended keeled edge to it.  The beak itself curved downwards and ended in a sharp point which may have aided the animal in selectively feeding on vegetation.  Inside its mouth, it had three long teeth coming from the top which may have helped the little fellow to strip soft leaves off of plants.  Some people hypothesize that ceratopsians like Aquilops may have been omnivorous as well, supplementing their diets with meat from time to time, possibly insects or carrion.  In the back of its mouth, Aquilops had rows of small teeth that appear to have been good for crushing plant material.  It also had proportionally huge, round eye sockets and when alive, may have been crepuscular, most active at dawn and dusk, or maybe even nocturnal, most active at night, to help avoid predation.  On the back of the skull Aquilops had a small frill and pointed jugal bones (cheek bones) on either side of its face behind the eyes.  It was probably able to walk on its hind legs or on all fours if it wanted to.  We can hypothesize this based on the limb proportions we see in other early ceratopids like Yinlong and Archaeoceratops.

That is all for this week!  Also special thanks to paleontologist, Andrew Farke, for lending his expert input on my painting and review of this amazing little dinosaur.  Stay tuned for next week when I review the last prehistoric animal of 2014! (It's going to be a big one.) If you have any requests for the upcoming beasties please do not hesitate to comment below or on our facebook page. 

References

 Farke, Andrew A.; Maxwell, W. Desmond; Cifelli, Richard L.; Wedel, Mathew J. (2014-12-10). "A Ceratopsian Dinosaur from the Lower Cretaceous of Western North America, and the Biogeography of Neoceratopsia". PLoS ONE 9 (12). 

Pampaphoneus: Prehistoric Animal of the Week

This week, as requested by one of our fans on facebook, we will be looking at a truly intimidating carnivore that has distant ties with us humans.  Make way for Pampaphoneus biccai!  Pampaphoneus lived in what is now Brazil during the middle Permian Era, about 260 million years ago, tens of millions of years earlier than the first dinosaurs.  When alive, because of its teeth, scientists believe Pampaphoneus was a meat-eater, possibly hunting other reptiles it coexisted with.  Pampaphoneus is only known from one skull but by comparing its proportions to more complete relatives on the fossil record, its snout to tail length can be estimated somewhere between four and six feet long.  The name, Pampaphoneus, translates to "killer from the Pampas" in reference to the area of Brazil in which the fossil was discovered.

Life reconstruction of two Pampaphoneus getting up from a snooze by Christopher DiPiazza.

 Visually, Pampaphoneus is difficult to place compared to animals that are alive today.  It was clearly reptilian but it has some striking mammalian features as well, especially in its teeth.  This is because Pampaphoneus was a kind of dinocephalian.  Dinocephalians are considered "mammal-like reptiles" and illustrate one of the branches of the reptilian family tree that was on its way to becoming mammals.  These peculiar creatures came in a variety of sizes and shapes during the middle Permian.  Some ate plants, others ate meat, most had some sort of knobby protrusions on their skulls, and many of them had long teeth.  By human standards they were pretty ugly, not gonna lie.  Ugly in a beautifully fascinating way, though!  Sadly, dinocephalians never actually made it that far, however, having disappeared from the fossil record pretty abruptly around 260 million years ago, but the Permian Era was full of other mammal-like reptiles, which would eventually give rise to true mammals like us hundreds of millions of years later.  The very famous, Dimetrodon, is another kind of mammal-like reptile, but is not a dinocephalian.

Pampaphoneus biccai skull

Pampaphoneus is interesting because it is the only dinocephalian found in South America.  All other known dinocephalians are from either South Africa or Russia.  This tells us that during the Permian era, these mammal-like reptiles had to have had a way to disperse from continent to continent.  They were able to do this quite easily because back then, the seven continents we have now were actually joined to form one massive land mass, called Pangea.  Finding similar fossils on different continents helps scientists map out closely how the continents at one point were joined together and how long ago they separated.

That is all for this week!  Join us next time for another Prehistoric Animal of the Week!  As always feel free to comment below or on our facebook page! 

References

Angielczyk, K. D. (2009). "Dimetrodon is Not a Dinosaur: Using Tree Thinking to Understand the Ancient Relatives of Mammals and their Evolution". Evolution: Education and Outreach 2 (2): 257–271. doi:10.1007/s12052-009-0117-4.

Cisneros, J.C.; Abdala, F.; Atayman-Güven, S.; Rubidge, B.S.; Şengör, A.M.C.; Schultz, C.L. (2012). "Carnivorous dinocephalian from the Middle Permian of Brazil and tetrapod dispersal in Pangaea". Proceedings of the National Academy of Sciences of the United States of America 109 (5): 1584–1588. doi:10.1073/pnas.1115975109.