Meet Inguza, the Smallest Penguin from Africa

Inguza is fast becoming one of my favorite fossil penguins.  Last December, I spent several weeks in South Africa studying fossil penguin bones in museums and at field sites with my friend and colleague Daniel Thomas.  Much of our time was spent examining, measuring, and analyzing bones of a somewhat runty penguin named Inguza predemersus.  This species was on the small end of the scale, and would have stood about chin-high next to the living Blackfooted Penguin (a species that is also known as the Jackass Penguin or the African Penguin).  Bones of Inguza are very common in the Langebaanweg Quarry, a famous fossil site that has produced some of the most amazing fossils in Africa, including the remains of a miraculous short-necked giraffe and Africa’s first fossil bear (completely unexpected as no bears live on the continent today).  Daniel Thomas and I were able to learn a lot about the evolutionary history of African penguins by studying Inguza, and I’ll post more about that soon.

A skeletal reconstruction of Inguza predemersus with extant Blackfooted Penguin (Spheniscus demersus) for scale, from Ksepka and Thomas (2011). Blackfooted penguin art by Barbara Harmon, Inguza art by Kristin Lamm

Holding the bones of Inguza side by side with bones from modern Blackfooted Penguins, I often wondered whether the two had ever met.  Among the hundreds of penguin bones from the Langebaanweg quarry, there is no trace of Blackfooted Penguin remains.  The youngest Inguza fossils are about 5.1 million years old, and the oldest Blackfooted Penguin bones are between 250,000 and 400,000 years old.  There’s a pretty large gap in the African fossil record between these points though, where few marine birds of any sort are known.  It’s possible that at some time within that interval, the last Inguza individuals noticed a new neighbor in their colonies as the founding Blackfooted Penguin population arrived.  Perhaps they lived side by side, choosing different prey. Perhaps they jostled uneasily for nesting sites.  Perhaps the new arrivals even contributed to the extinction of Inguza by outcompeting that species.

Or, its possible the last Inguza died out before any Blackfooted Penguins set foot in Africa.  In the most extreme scenario, there may have been NO penguins at all in Africa at some point 1-4 million years ago.  Blackfooted Penguins could have arrived into a “penguin vacuum” and set up shop wherever they pleased.  Not knowing what happened is one of the reasons we keep going back to the field to collect more fossils.  As we fill in the blank parts of the record, we will come closer to understanding what actually happened on those beaches millions of years ago.

Reference:

Ksepka, D.T. and D.B. Thomas. In press 2011. Multiple Cenozoic invasions of Africa by penguins (Aves, Sphenisciformes). Proceedings of the Royal Society B Biological Sciences.