Giant Ground Sloth

Giant Ground Sloths were large, bumbling herbivores that evolved in South America, and were among some of the last of the large mamimals to arrive in the prehistoric San Francisco meadow that later became the site of the San Francisco Bay. The Giant Ground Sloth (Megatherium) was of similar ecological importance to the Columbian Mammoth, grazing on overgrown shrubs and distributing nutrients back into the soil with their large fecal droppings. Here lies the significance of large mammals, and their absence can be drastic and traumatic to an ecosystem by ceasing the flow of nutrients. There was a mass extinction of large mammals in the Pleistocene era, although the exact cause of this extinction remains puzzling to Bay Area paleontologists today.

The natural cycle of climate change remains a leading theory, however human hunting may have contributed to the disappearance of the Giant Ground Sloth. At the time of their extinction, the climate was relatively stable, and carbon dating of fossils has correlated their extinction with the timing of the arrival of humans to the Americas. Today, in the midst of a sixth mass extinction, scientists hope to learn from the Pleistocene extinctions to prevent such events from happening today.