Terror Birds

Terror Bird and Mesohippus Prey

(Mesohippus is My Little Drunk Pony)

Phorusrhacidae were a Family of carnivorous flightless birds that went extinct around the same time Man appeared...possibly later.  They originated in South America and migrated to North America.  There is some evidence that they even made it to Africa.  Some species of Terror Birds were almost 10 feet  (9 meters) tall.  These birds had huge heads and beaks.  The largest measured beak was 18 inch s (46 cm) long and the beak and skull together measured 28 inches (71 cm).  The neck muscles were very powerful and could generate a tremendous amount of force to kill prey.  The beak of the terror birds had a notch like many birds of prey have on their beaks.  You can think of the size of the beak as larger than a basketball.

If you look closely at he feet you see that this horse did not have a single hoof toe.  In fact, it had three toes on each foot. Over the course of the evolution of horses eventually horses ended up with one toe or hoof on each foot.

There is an excellent documentary that I recommend.  It is called Walking With Prehistoric Beasts. 
This BBC documentary is the sequel to Walking With Dinosaurs.  There is a scene in one episode I like to call "my little drunk pony." During this time horses had not yet evolved large size.  In the scene a group of horses that were about as large as a medium sized dog, ate some fermented grapes and got plastered...that is, they got drunk.  Then when a Terror Bird comes hunting the little horses are in big trouble.  It is hard to run away when you are completely soused or drunk. Note the grapes scattered on the ground in my drawing.

There were 17 species of Terror Birds over the years of their existence...and some were only a foot tall.  But as previously mentioned, some were huge.   Remember that birds are now often called "Avian Dinosaurs."  You could kind of think of this animal type as the Tyrannosaurs of their day.  When the meteorite wiped out T. rex and company the Terror Birds took the niche of predators.  Some paleontologists think that Terror Birds were out-competed by saber tooth cats and wolves in most parts of the world, but in South America Terror Birds were the top dog...ok, top predator.  Terror birds lived for 60 million years and only went extinct somewhere between 2.5 million and 200,000 years ago.  Some evidence suggests that they may have even lived into the age of Man.  There is even some speculation that humans  may have wiped the Terror Birds out.  ...or been the cause of Terror Bird extinction.

Skeleton of Terror Bird

from Museum of Ancient Life, Lehi, Utah