Lavocatavis
Encyclopedia
Lavocatavis is an extinct genus of phorusrhacoid or "terror bird" from the Eocene
of Algeria
. A fossilized femur
was described from the Glib Zegdou Formation in 2011 and is the only known specimen of Lavocatavis. The species was designated L. africana.
s or island hopping
. Currents traveled westward in the South Atlantic during the early Paleocene, making it unlikely that phorusrhacoids traveled on floating islands. The ancestors of Lavocatavis most likely traveled between very large islands that existed on what are now the submerged Rio Grande Rise and Walvis Ridge
. However, it is also possible that the ancestors of Lavocatavis retained some of their flight ability and were able to travel between islands with more ease than flightless birds. If this was the case, Lavocatavis became flightless independently in a case of evolutionary convergence with other flightless phorusrhacoids.
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
of Algeria
Algeria
Algeria , officially the People's Democratic Republic of Algeria , also formally referred to as the Democratic and Popular Republic of Algeria, is a country in the Maghreb region of Northwest Africa with Algiers as its capital.In terms of land area, it is the largest country in Africa and the Arab...
. A fossilized femur
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
was described from the Glib Zegdou Formation in 2011 and is the only known specimen of Lavocatavis. The species was designated L. africana.
Paleobiogeography
The oldest phorusrhacoids are from South America and Antarctica, suggesting that the ancestors of Lavocatavis migrated into Africa from the west. During the Eocene, the Atlantic Ocean separated South America from Africa by at least 1000 kilometres (621.4 mi), ruling out a land migration. For a flightless terrestrial bird like Lavocatavis, the only means of entering Africa would be through rafting on floating islandFloating island
A floating island is a mass of floating aquatic plants, mud, and peat ranging in thickness from a few inches to several feet. Floating islands are a common natural phenomenon that are found in many parts of the world. They exist less commonly as a man-made phenomenon...
s or island hopping
Island hopping
Island hopping is a term that refers to the means of crossing an ocean by a series of shorter journeys between islands, as opposed to a single journey directly across the ocean to the destination.- Forms :...
. Currents traveled westward in the South Atlantic during the early Paleocene, making it unlikely that phorusrhacoids traveled on floating islands. The ancestors of Lavocatavis most likely traveled between very large islands that existed on what are now the submerged Rio Grande Rise and Walvis Ridge
Walvis Ridge
Walvis Ridge is an ocean ridge in the southern Atlantic Ocean, extending for thousands of miles, off the coast of southwest Africa. Both it and the Rio Grande Rise originated from hotspot volcanism now occurring at the islands of Tristan da Cunha , 300 kilometres east of the crest of the...
. However, it is also possible that the ancestors of Lavocatavis retained some of their flight ability and were able to travel between islands with more ease than flightless birds. If this was the case, Lavocatavis became flightless independently in a case of evolutionary convergence with other flightless phorusrhacoids.