Acrocanthosaurus and Spinosaurus plus Orca and Shark in Convergent Evolution

Acrocanthosauarus

(new drawing)

Acrocanthosaurus was a large predatory dinosaur or Theropod of the EARLY Cretaceous Period.  This makes it quite a find.  We don't have a lot of specimens of dinosaurs from the Early Cretaceous Period.  This dinosaur was found in Oklahoma.  It has spines that indicate a small sail on it's back, but this is not due to any relationship with the Spinosaur Family.  This type of situation is called Convergent Evolution.  This type of evolution is when organisms that are not closely related have evolved a similar trait independently.  Acrocanthosaurus had a large head with a wide snout.  It preyed on other dinosaurs...probably usually herbivores.  NOTE:  This hadrosaur that is the prey appears to be a Parasaurolophus and I admit that they evolved later in the Cretaceous so this drawing is somewhat inaccurate... unless there was some convergent evolution going on in the Early Cretaceous and this only LOOKS like a Parasaurolophus.  ...due to convergent evolution.  The following drawings are from previous posts:

Spinosaurus fishing with Young

Spinosaurus goes Fishing

Spinosaurus Swimming

Spinosaurus Hunting with Young

Baryonyx the Spinosaur

Baryonyx was a Spinosaur that did not have a sail, but like all Spinosaurs it had a long narrow snout and preyed primarily on fish. We also know that Spinosaurus and its relaations like Baryonyx lived in what is now North Africa in the later Cretacous.  Acrocanthosaurus lived in what is now North America in the early Creatceous.  

Orca vs Great White Shark

(new drawing)

Another example of Convergent Evolution is sharks and killer whales. Killer whales are also called Orcas.  Both sharks and killer whales have similar traits of fins or flippers, a dorsal fin on the back, and a streamlined body.  Having those traits is useful in an ocean environment so even though a whale is a mammal and a shark is a cartilaginous fish, they have some similar traits.

Orcas or Killer Whales do not like sharks...unless you consider they probably like eating them.  Some killer whales will ram and or bite sharks...even the Great White Sharks.  The darkened areas of the drawing on the animals should be colored black.

Dolphin 1

The dolphin is also shaped similarly to the Killer Whale and Great White Shark. 

NOTE:  All drawings in printable form can be found by hitting the buttons above.  The new drawings are usually at the bottom of the lists.  Look for the titles of the drawings in the lists.  Since Acrocanthosaurus was a Cretaceous Period dinosaur the drawing is at the bottom of the Cretaceous list under Cretaceous animals.