March of the Fossil Penguins

Fossil penguin discoveries and research

South Africa’s Nuclear Penguin

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South Africa, host of the next World Cup, is one of the best places on Earth to see penguins in the wild.  Only one species of penguin lives there today (the Jackass Penguin Spheniscus demersus), but it is possible to visit quite up close with these charming birds. The Jackass Penguin earns its name for its abrasive braying call rather than any foolhardy behavior.  Historically, this species has place of pride as the first penguin to be encountered by European explorers.  This momentous occasion occurred as Vasco da Gama’s voyage around the Cape of Good Hope landed for supplies near present day Mossel Bay in 1497 (of course, native peoples in South America, Africa, New Zealand and Australia were certainly well aware of penguins for hundreds if not thousands of years prior to this encounter).  It is not recorded how the penguins greeted their strange visitors, but the humans behaved as customary when encountering wondrous new life forms by plundering a good number of them to eat.  Relations have since improved between our species and theirs, and Jackass Penguins are a fixture at many aquariums and zoos worldwide.

While Spheniscus demersus is the only species surviving on the coast of Africa today, several fossil species have been described.  Interestingly enough, all South African penguins are from the Miocene-Pleistocene Epochs – substantially younger than the oldest fossils from other continents.  Whether penguins arrived to Africa late, or we simply have not searched diligently enough for them in older rocks, remains to be seen. One interesting and fortuitous fossil discovery from South Africa was the unearthing of Nucleornis insolitus during excavations for the Koeberg nuclear power station.  Geroge Gaylord Simpson, featured in the last post, named the species in 1979. The etymology of the genus name should be obvious.  Unfortunately only two foot bones – tarsometatarsi in avian anatomical lingo – were found.  Because the purpose of the excavation was to sink a foundation for the power plant, not search for penguin fossils, little effort was devoted to deciphering the age of the rocks in which the penguin bones were found.  They are thought to be Miocene in age – roughly between 5 and 23 million years old, and probably closer to the lower end of that range. Very little is known about Nucleornis insolitus because we have so little of the skeleton.  Based on the foot bones, the species was comparable to the living Jackass Penguin in size.  In all of the preserved morphological details, the tarsometatarsus resembles that of living penguins.  While it is not possible to definitively say whether Nucleornis shared the most recent common ancestor as the living penguin species, it was at least very closely related.  These scraps of fossil represent one piece of the puzzle of how penguins arrived and radiated in Africa, but much more work remains to be done before we will understand the whole story.


References:

Simpson, G.G. 1979. A new genus of Late Tertiary penguin from Langebaanweg, South Africa. Annals of the South African Museum 78: 1–9.

Written by Dan Ksepka

May 29, 2010 at 11:36 pm

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