Showing posts with label Plesiosaur. Show all posts
Showing posts with label Plesiosaur. Show all posts

Monday, December 10, 2012

Top 10 Favorite Dinosaurs by Zack Neher (Part 3)

Part three of my Top Ten Favorite Dinosaurs list.  Enjoy!

3. Masiakasaurus
A fairly small dinosaur at only around six feet, Masakisaurus knopfleri, as discussed IN A PREVIOUS POST, was named for the famous musician Mark Knopfler.  The animal, found in Madagascar, was named in 2001 by Matthew Carrano, Catherine A. Forster, and Scott Sampson, the author of Dinosaur Odyssey and the dude from Dinosaur Train.  Living on what was still an island, the little dinosaur lived about 70 MYA during the  Late Cretaceous Period, and was a contemoporary of the abelisaur Majungasaurus, the bird-like Rahonavis, and the sauropod Rapetosaurus.  Although Masiakasaurus sounds pretty unremarkable thus far, a quick glance at the picture below (which many of you have no doubt already done) says otherwise: Masiakasaurus definitely had some funky teeth!  These teeth are clearly not suited tearing into food like the teeth of Allosaurus or Velociraptor would be, and many paleontologists (including myself, even though I am not really a paleontologist.  I guess it would be better to say "many paleontologists, paleontologists-in-training, and myself."  There, much better.) believe that these weird, pointy teeth are an evolutionary adaptation to a piscivorous (fish-based) diet.  A look at various marine reptiles such as the plesiosaurs (like Elasmosaurus) and Liopleurodon show a similar pattern of interlocking teeth that point outside of the mouth.  Excellent when it comes to catching fish, and not so excellent when it comes to most, if not all, other diets, be they meat- or plant-based.  

TO BE CONTINUED IN PART 4

Wednesday, August 8, 2012

Top Ten: Extinct Sea Monsters (Part 5 of 5)

Our final edition of "Top Ten:  Extinct Sea Monsters!

9.  Tanystropheus - Living during the Middle Triassic Period, Tanystropheus is somewhat of a misfit amongst this group, as he is not really a sea-monster, and was, at most, a semi-aquatic animal (think otters).  Purportedly piscivorous, Tanystropheus fossils are usually found in semi-aquatic sites.  Its neck has been likened to that of the Plesiosaurs, like Elasmosaurus.  They would all use their necks to surprise a group of fish, long before the fish would be able to see the body of the reptile. Remains have been discovered throughout France, Germany, and Italy, amongst other places. 

10.  Tylosaurus - Interestingly enough, the closest living relative of the extinct mosasaurs, of which Tylosaurus is a member, are the monitor lizards, like the Komodo dragon.  Both the monitor lizards and the mosasaurs have a third eye on the top of their heads, although it just looks like a little white dot on the top of the head of the monitor lizard.  It doesn't work in the same fashion as their other eyes, however.  Look towards a light (not the sun, because apparently that can actually be harmful) and close your eyes.  You can still still some light, right?  Now, move your hand back and forth in front of your face, between your eyes and the light.  Can you see how the light changes?  You can't see anything more distinct than the fact that something moved between you and that light.  That is what the third eye of monitor lizards and mosasaurs would have been like.  Tylosaurus also inhabited the Western Interior Seaway during the Late Cretaceous.  Remains, amongst other places, have been discovered in Alabama and Kansas, amongst other places.

So that concludes our "Top Ten:  Extinct Sea Monsters" edition!  Unfortunate that we had to break it up into five parts, to be sure, but hey, that's life!

This post is part of the "Top Ten: Extinct Sea Monsters" series.  For the rest of the posts in this series, click HERE.  

Top Ten: Extinct Sea Monsters (Part 3 of 5)

 5.  Elasmosaurus - Next up on our trip across time is Elasmosaurus.  One of the largest of the Plesiosaurs ever discovered, Elasmosaurus grew up to 46 feet long, which was about half neck.  Equipped with a fairly small head, Elasmosaurus would have been incapable of going after large prey, so it would have mostly stuck with fish.  Elasmosaurus lived during the Late Cretaceous, a time when much of North America was "Beneath the Waves," under something that we call the "Western Interior Seaway."   Remains of this animal were first uncovered in Kansas, but it almost certainly swam all over the seaway, including in Colorado.

6.  Dunkleosteus - Dunkleosteus, a creature we talked about a few weeks ago in our post about the Coelacanth, is another fascinating animal.  Almost thirty-five feet in length, Dunkleosteus was a member of the Placoderms, a group of armored fish that were only around for about 50 MYA.  A long time, to be sure, but not very long compared to the 400 million year reign of the sharks.  While the Placoderms themselves lived during the Silurian and Devonian Periods, they went extinct during the transition to the Carboniferous Period, at the end of the Devonian.  Dunkleosteus fossils have been discovered in North America, Poland, Belgium, and Morocco.

 COMING UP:

7.  Archelon
8.  Leedsichthys
9.  Tanystropheus
10. Tylosaurus

This post is part of the "Top Ten: Extinct Sea Monsters" series.  For the rest of the posts in this series, click HERE.  

Top Ten: Extinct Sea Monsters (Part 2 of 5)

So why did I split this post up into five parts?  Well, originally it was all just one big post, but it was simply too big, like so often happens.  So I will just post the rest of the parts throughout the next few days.  So here is part number two!
3.  Liopleurodon - A member of the short-necked Plesiosaurs, or Pliosaurs, Liopleurodon was the top predator of the Middle and Late Jurassic shallow seas that covered Europe at that time.  Fossils of Liopleurodon have been found in England, France, Germany, and Russia. 


4.  Shonisaurus - Shonisaurus is a fascinating example of convergent evolution.  When similar environmental and ecological pressures went to work on the ancestors of Shonisaurus, and the rest of the ichthyosaurs, as well as the ancestors of the dolphins and porpoises, they produced very similar results in very different kind of animals.  Shonisaurus and the rest of the ichthyosaurs are marine reptiles, while the dolphins and porpoises are both mammals.  Shonisaurus lived during the Late Triassic Period, right around when the dinosaurs were first making their debut.  At least thirty-seven skeletons of this giant have been discovered in Nevada. In fact, Nevada is still a fantastic place to see some of these creatures, especially Berlin Ichthyosaur State Park in Berlin, a few hours outside of Reno (pictured below)!  This is where the first bones belonging to Shonisaurus were actually discovered!  Definitely high on the list of places that I want to go!



Coming Up:
5.  Elasmosaurus
6.  Dunkleosteus
7.  Archelon
8.  Leedsichthys
9.  Tanystropheus
10. Tylosaurus

This post is part of the "Top Ten: Extinct Sea Monsters" series.  For the rest of the posts in this series, click HERE.  
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