Wednesday, May 21, 2014

Happy Birthday to Mary Anning!

Today is the 215th birthday of Mary Anning!  In case you didn't know, Mary Anning was one of the most important early fossil hunters in history.  Starting when she was just a child, she was responsible for the discovery of several important species.  She lived in Southern England and used to do all her hunting along the Jurassic fossil beds known as the Lyme Regis formation.


Mary Anning discovered well known species like the pterosaur, Dimorphodon, and the first known plesiosaur and ichthyosaurs to science!

Ichthyosaurus, a famous prehistoric reptile discovered by Mary Anning back in the 1800s.

Sunday, May 18, 2014

Dakosaurus: Prehistoric Animal of the Week

Before we get into this week's creature, let me just remind everyone that the newest installment to the Godzilla franchise came out this past weekend.  I saw the movie in IMAX 3D last night and it was awesome.  It's really cool to see the most famous movie dinosaur of all time on the big screen again.


You may know that we have reviewed a Godzilla dinosaur on here before.  This week we will be looking at yet another prehistoric beast with connections to the "King of the Monsters."  Check out Dakosaurus andiniensis!

Dakosaurus andiniensis by Christopher DiPiazza.

Dakosaurus was an extinct genus of crocodile that belonged to the family called Metriorhynchidae.  Metriorhynchids were prehistoric crocodiles that were specially adapted to living in the ocean.  Their limbs were like flippers and their flattened tails even had flukes on them like sharks, dolphins, and their fellow reptiles, the ichthyosaurs and mosasaursDakosaurus andiniensis lived in the oceans that once covered what is now Argentina during the Late Jurassic to the Early Cretaceous, about 145 to 140 million years ago.  The genus name, Dakosaurus, translates to "biter lizard" in reference to the creature's formidable teeth.  There are actually a few species within the Dakosaurus genus, but I want to focus specifically on the species, Dakosaurus andiniensis, because of its nickname, "Godzilla", given to it by the scientists who discovered its skull.  It earned this name because of its unusual snout, which was short and deep, and extremely long, serrated teeth.  It measured about thirteen feet long from snout to tail and would have been a meat-eater.

Fossilized skull of Dakosaurus andiniensis.  It looks mean!

Dakosaurus' teeth were unique in that they were both laterally compressed and serrated.  This is a feature more commonly seen in certain kinds of meat-eating dinosaurs.  In fact, when the isolated teeth of Dakosaurus were first discovered, they were initially believed to have been from a Megalosaurus, not a crocodile.  The skull of Dakosaurus had openings towards the back, called fenestrae, that would have anchored powerful jaw muscles in life.  This, combined with the fact that its teeth were deeply rooted within the jaws, means that Dakosaurus would have been able to bite down with extreme force.  It is likely that Dakosaurus was a top predator and was able to hunt most other animals it shared its habitat with, including other marine reptiles. 

Nobody is exactly sure how Dakosaurus would have reproduced.  There is evidence that other prehistoric marine reptiles, like mosasaurs and ichthyosaurs, gave birth to live young in the water, much like modern whales.   Dakosaurus' closest relatives, the crocodilians, we know lay eggs in nests, however.  It is possible Dakosaurus could have hauled out onto beaches to lay eggs like modern sea turtles do if it was like the rest of its family.

That is all for this week!  Next week I shall be in London visiting friends.  Tune in for a special English dinosaur of the week!  As always comment below or on our facebook page.

References

Gasparini Z, Pol D, Spalletti LA. 2006. An unusual marine crocodyliform from the Jurassic-Cretaceous boundary of Patagonia. Science 311: 70-73.

Vignaud P, Gasparini ZB. 1996. New Dakosaurus (Crocodylomorpha, Thalattosuchia) from the Upper Jurassic of Argentina. Comptes Rendus de l'Académie des Sciences, Paris, 2 322: 245-250.

Sunday, May 11, 2014

Stenopterygius: Prehistoric Animal of the Week

Happy Mother's Day to all you moms out there!  This week, in honor of mothers everywhere, we will be looking at a prehistoric reptile who's motherhood was preserved in fossilized form forever. (aw)  Check out Stenopterygius

Stenopterygius was a marine reptile belonging to the same order as Ichthyosaurus.  It measured about ten feet long from snout to tail and would have lived in oceans covering what is now Europe during the Early Jurassic period, about 180 million years ago.  The genus name, Stenopterygius, translates to "Narrow Wing". (or in this case, flipper)  There have been several species assigned to this genus. 

Stenopterygius quadriscissus life reconstruction by Christopher DiPiazza.

Like all ichthyosaurs, Stenopterygius was a reptile, but had evolved a body shape very similar to that of a fish for a marine lifestyle.  Instead of feet and claws, it had flippers, dorsal fin, and tail fluke.  Its eyes were large and it sported a narrow, almost beak-like mouth filled with many sharp teeth for snagging prey.  Stenopterygius and Ichthyosaurus were actually very similar in appearance but can be told apart by Stenopterygius' proportionally smaller head and shorter snout.

Fossilized skeleton of a mother Stenopterygius with young.

Stenopterygius would have spent it's entire life at sea but would have still needed to come to the water's surface to breathe.  Unlike modern sea turtles, which still need to come to shore to lay eggs on land, ichthyosaurs like Stenopterygius actually gave birth to live young in the water.  We know this because of beautifully preserved Stenopterygius fossils consisting of mothers with the skeletons of unborn babies still inside their body cavities.  We even know that the babies would have been born tail-first!  

That's it for this week!  Join me next time for another awesome prehistoric creature!  As always feel free to comment below or on our facebook page.  Is everyone excited for that new Godzilla movie coming out?  I sure am...  (hint-hint!)

References

Böttcher R. 1990. Neue Erkenntnisse über die Fortpflanzungsbiologie der Ichthyosaurier. Stuttgarter Beiträge zur Naturkunde Serie B (Geologie und Paläontologie) 164: 1-51

Maxwell, E. E.; Fernández, M. S.; Schoch, R. R. (2012). "First Diagnostic Marine Reptile Remains from the Aalenian (Middle Jurassic): A New Ichthyosaur from Southwestern Germany". In Farke, Andrew A. PLoS ONE 7 (8): e41692. doi:10.1371/journal.pone.0041692.

Michael W. Maisch and Andreas T. Matzke (2000). "The Ichthyosauria". Stuttgarter Beiträge zur Naturkunde: Serie B 298: 1–159.

Sunday, May 4, 2014

Velafrons: Prehistoric Animal of the Week

Happy Cinco de Mayo everyone!  Today, like last year, we will be looking at a dinosaur that used to call Mexico home.  Check out Velafrons coahuilensis!  The name sounds just sexy.  Say it out loud with me.  VELAFRONSSSSS.  yeah...

Velafrons was a hadrosaurid (duck-billed) dinosaur that was alive during the late Cretaceous period, 72 million years ago.  It measured about thirty feet long from beak to tail and was a plant eater.  The genus name, Velafrons, translates to "sail forehead" and the species name is in reference to Coahuila, Mexico, where some of its remains have been found.  When alive, Velafrons would have coexisted with Coahuiliceratops

Velafrons life reconstruction by Christopher DiPiazza

Velafrons was a kind of hadrosaurid called a Lambeosaurine.  Lambeosaurine hadrosaurs tended to have had more narrow bills and elaborate crests on their heads, which were hollow and could have been used for producing sound.  Another example of a lambeosaurine hadrosaur is ParasaurolophusVelafrons was most closely related to Corythosaurus and Hypacrosaurus, however.  

Velafrons is known from a skull and partial skeleton.  It is believed that the remains found were actually from a juvenile animal so it could have possibly grown to have been even larger than thirty feet at older ages.  The crest may have also been larger in an adult as well.  Paleontologists hypothesize this because the crest of Velafrons is similar in shape to crests seen in juveniles of other, more completely known lambeosaurines, like Corythosaurus and Hypacrosaurus.  It is totally possible, however, that the Velafrons found was actually an adult after all and just had a...youthful look about it.

Velafrons skull at the Paleontology Museum of Guadalajara.

Like all hadrosaurs, Velafrons had a beak in the front of its mouth for clipping vegetation and hundreds of tightly packed teeth in the back of its mouth for chewing.  It could have walked on all four legs or reared up on its hind legs to run or reach higher leaves if it needed to.  The tails of hadrosaurs like Velafrons tended to be wide longitudinally (up and down ways) and stiff due to the way the vertebrae fit together. They would have been good counterbalances for when the dinosaurs were walking.  Hadrosaurs also likely used their tails like club-weapons to keep predators at bay if need be.

That's it for this week!  As always feel free to comment below or on our facebook page!  Happy Cinco de Mayo!

References

Gates, Terry A.; Sampson, Scott D.; Delgado de Jesús, Carlos R.; Zanno, Lindsay E.; Eberth, David; Hernandez-Rivera, René; Aguillón Martínez, Martha C.; and Kirkland, James I. (2007). "Velafrons coahuilensis, a new lambeosaurine hadrosaurid (Dinosauria: Ornithopoda) from the Late Campanian Cerro del Pueblo Formation, Coahuila, Mexico". Journal of Vertebrate Paleontology 27 (4): 917–930. doi:10.1671/0272-4634(2007)27[917:VCANLH]2.0.CO;2.