Name: Ajnabia
(stranger/foreigner).
Phonetic: Aj-nah-ne-ah.
Named By: Nicholas R.Longrich, Xabier Pereda
Suberbiola, R. Alexander Pyron & Nour-Eddine Jalil -
2020.
Classification: Chordata, Reptilia, Dinosauria,
Ornithischia, Ornithopoda, Hadrosauridae, Lambeosaurinae,
Arenysaurini.
Species: A. odysseus (type).
Diet: Herbivore.
Size: Uncertain due to lack of fossils, but
holotype individual very roughly estimated to be about 2.6 meters
long.
Known locations: Morooco - Ouled Abdoun Basin.
Time period: Maastrichtian of the Cretaceous.
Fossil representation: Partial remains.
Ajnabia
is a genus of hadrosaurid
dinosaur that lived during the late
Maastrichtian period towards the end of the Cretaceous period.
Ajnabia made headlines in the paleontological world
when it was
described as this represented the first time that hadrosaurid dinosaur
fossils had been found in Africa. Hadrosaurid dinosaurs were for a
long time associated with North America and Asia, though increasing
numbers of hadrosaurid dinosaur fossils are being found from European
and South American deposits.
Africa
at the time of the late Cretaceous was thought to have been cut off
from the rest of the world meaning that hadrosaurs could not spread
into Africa. This theory was once proposed for the lack of
hadrosaurid dinosaur fossils in South America, or at least until they
started being found there. It may well be that as sea levels went up
and down, and continents shifted, temporary land bridges may have
occasionally appeared, allowing for dinosaurs like hadrosaurs to
spread out into new territories.
The
only other explanation is that Ajnabia either swam
or drifted across
the sea from Europe to settle in Africa. Indeed, Ajnabia
is noted
for a strong similarity to the hadrosaurid genus Arenysaurus
which is
known from Europe. Could it be that Ajnabia was
a freak occurrence
of a dinosaur crossing the sea, perhaps already dead and floating
along the surface because its body was bloated by gasses? Or does the
Ajnabia holotype represent an individual from a
stable population of
hadrosaurs living in Africa?
Further reading
- The first duckbill dinosaur (Hadrosauridae: Lambeosaurinae)
from Africa and the role of oceanic dispersal in dinosaur
biogeography. - Cretaceous Research: 104678. - Nicholas
R.Longrich, Xabier Pereda Suberbiola, R. Alexander Pyron
& Nour-Eddine Jalil - 2020.