IPC Roundup 3: Mountain Penguins
Penguins rarely make it to altitudes more than a few feet above sea level. In an interesting case reported at the International Penguin Conference, Dr. Carolina Acosta Hospitaleche presented a talk on penguin fossils from Cerro Plataforma in the Patagonian Cordillera. No, these were not mountain climbing penguins exploring treacherous passes. These fossils were transported upward long after their demise roughly fifteen million years ago. Along with the penguin bones fossilized seashells and shark teeth were also discovered, clear indicators that the bones were deposited in an oceanic environment.
Cerro Plataforma is an unexpected place to find penguins, because it is nearly a mile about sea level today. The fact that marine fossils have been lifted so spectacularly skyward from their original resting place on the seafloor speaks to the tremendous geological forces responsible for building the Andes – a process that still continues today and periodically manifests itself in severe earthquakes. These particular bones appear to have belonged to Palaeospheniscus bergi, one member of a radiation of penguins that thrived in South America during the Miocene but ultimately died out. The penguins may be a clue to the mystery of where the Cerro Plataforma marine rocks actually came from. There is some debate over whether they formed in the Atlantic or Pacific, a seemingly simply question that is obfuscated by the jumbling of the rocks under tectonic forces. It is interesting to note that regardless of whether the Cerro Plataforma rocks turn out to have been formed in the Pacific Ocean or the Atlantic Ocean, Palaeospheniscus penguins have been found all the way from Argentina to Peru. This indicates they not only lived in both oceans, but that their range stretched over a huge range of latitude, from near the Equator presumably down close to the tip of Tierra del Fuego. Thus these penguins achieved a pattern of distribution like that of Spheniscus penguins today, wrapping around almost all of the habitable areas of South America. It is likely they made it out onto nearby islands as well, but so far we have almost no fossils from offshore localities to verify this.
Acosta-Hospitaleche, C. and M. Griffin. 2013. Middle Cenozoic penguin remains from the Patagonian Cordillera. 8th International Penguin Conference Abstracts: 31.