Wednesday, 7 September 2011

The First Ever Species Of African Terror Bird

Many periods throughout Earth history have been given the title the 'Age of'; similarly particular animal groups such as the 'Age of the Fish' during the Devonian, or the 'Age of the Dinosaurs' for the Mesozoic. The 10 million years after the extinction of the dinosaurs is sometimes referred to as the 'Age of the Terror Bird.' The terror birds were a group of flightless avians who could grow to sizes topping three metres and fed upon mammals using beaks the size of meat cleavers.

They lived on both American continents, Europe and even extended into Asia. While they were suppressed by other predators such as sabre toothed cats, they still remained formidable predators. However they never laid a talon upon African soil. However the discovery of a new fossil has changed this. According to the new research published by Cécile Mourer-Chauviré, Rodolphe Tabuce, M’hammed Mahboubi, Mohammed Adaci, and Mustapha Bensalah, very little is known about Africa’s fossil birds between 65 and to 48 million years ago. Part of this has to do with the rarity of bird remains. 

Birds are lightly built and their hollow bones are easily destroyed by the various processes which affect a body between the time of the animal’s death and when the bones are found. Add the difficulty of finding appropriate deposits where such bones might turn up and the fact that someone actually has to go looking for them, and it’s not altogether surprising that there is much we still have to learn about the birds which flourished in the wake of the end-Cretaceous mass extinction.

Bone b is the femur or Lavocatavis africana. CA, FAAC
and CF mark the anomalies which make the team think that
the bone belonged to a phorusrhacid. The images in the middle
is a reconstruction of what it might have been like in
life in relation to a human

At first glance, the new avian fossil Mourer-Chauviré and colleagues describe might not seem to add much to the overall picture of avian evolution in Africa. The specimen is little more than a nearly-complete right femur found in the roughly 48 million years old rock of western Algeria. In the context of what has been found before, though, the fossil is significant in that it’s from a land-dwelling bird. Many of the other fossil birds found in Africa were birds which lived along the prehistoric shoreline, and the new species from the Gour Lazib site represents the oldest terrestrial bird yet found on the continent. 
The suggestion that the bone might have belonged to a terror bird only sweetens the fossil find. The creature has been named Lavocatavis africanaWhile it is only known from a single right femur, a series of features have made the research team believe that is is a phorusrhacid. The flattened nature of the rear face of the bone shaft, the orientation of several knobs associated with muscle attachment, and the size of several other landmarks all appear to be consistent with the idea that Lavocatavis was a terror bird that – when fully restored – could have looked an average-sized human adult in the eye. 

The real question is how the species, or its ancestors, arrived on the African continent 48 million years ago. The less likely theory is that the ancestors of Lavocatavis arrived on wing and then lost their powers of flight. The theory suggested by the team is that the creature or its ancestors arrived by island hopping from Europe or crossed the Atlantic on rafts of vegetation broken off in a storm. 50 million years ago, the east coast of South America was significantly closer to the west coast of Africa, just 620 miles at the closest point.