Mosasaur Discovery Time

What is a Mosasaur? Mosasaurs are considered the Great Marine Reptiles that ruled the seas during the Cretaceous period. Although they are often referred to as the T-Rex of the seas, they were not dinosaurs, but reptiles that returned to the sea during the Cretaceous Period. Even though they are aquat- ic, these great beasts were still reptiles that breathed air, like sea turtles today. Also, fossil skin impressions show mosasaurs had a scaly skin, much like snakes.

What did a Mosasaur eat? It appears they could eat whatever they wanted. Stomach contents of mosasaurs reveal ammo- nites, bony fish, sea turtles, plesiosaurs, and even sea birds!

How did the Mosasaur swim? In 2011, Johan Lindgren and other scientists studied a well preserved mosasaur fossil. Lindgren suggests that the mosasaur held the front of its body rigid and used the rear of its body and tail for propulsion. This is also similar to how crocodiles swim. Another specimen that was studied had a partial body outline preserved. Based on the outline of this particular kind of mosasaur, it appears that it had a tail fluke, like that of a shark. This means they were probably very fast swimmers.

What color were Mosasaurs? New research shows that Mosasaurs were most likely a dark color, similar to a Sperm Whale coloration. The research done in 2014 by Johan Lindgren and other scientists states that this dark color scheme would help with thermoregulation, protect against UV radiation when at the surface, and provide camouflage when deep diving.

How big was the Mosasaur? Mosasaurs could be between 3-50 feet, depending on what kind of mosasaur it was. On aver- age, most mosasaurs were over 10 feet in length.

Mosasaur Silhouette Craft

About this craft: Learn about the Mosasaur through this silhouetted craft!

Recommended Age: 3+

SUPPLIES:

 Mosasaur Template sheet  Various shades of blue con- in 9” x 12”  Crayons struction paper  Scissors  Dark blue construction paper INSTRUCTIONS:

1. Cut out the Mosasaur silhouette. You can choose to use one or both of the silhouettes. Draw details on it, if desired, with the white crayon. Lay this aside. 2. Create an ocean backdrop for the mosasaur. Tear or cut the various shades blue construction paper (do not tear or cut out waves from the 9” x 12” sheet of Dark blue construction paper) into long wave-like shapes. 3. Glue “waves” down onto the dark blue construction paper. Kids can tear paper, cut paper or just glue the scraps down anywhere on the 9” x 12” dark blue construction paper. 4. Glue on a one of two sea dinosaur shapes. Don’t forget to draw the bubbles!