Mammals of Australia introductions of placental mammals into Australian fauna were about (rats), several thousand years ago (dingo), and 200 years ago (many species); the last two were made by humans. Some claims were made about placental mammal fossils from the Eocene of Australia, called "Tingamarra". These claims are based on only one found tooth having some characteristic features of condylarth, and were discussed widely. But both the age and placental nature of these fossils were challenged by other researchers. Monotremes are mammals with a unique method of reproduction: they lay eggs instead of giving birth to live young. Two of the five
The Marine Mammal Center of survivability for all patients, species combined. In the spring of 2013, environmental conditions limited to Southern California resulted in a higher than normal number of sea lion strandings. During this period, the Marine Mammal Center has taken in the overflow, approximately 65 patients. The Marine Mammal Center began in 1975 with bath tubs and small pools surrounded by a fence. In June, 2009 a multi-facility complex was opened to hold both the animals and the staff. It was built with recycled materials and utilizes sound boards made of sea weed. Donated solar panels provide approximately 20% of the facilities