The Marine Mammal Center weaning. At the center, they receive specialized veterinary care; diagnosed, treated, rehabilitated, and ideally, released back into the wild. Animals in need of assistance are usually identified by a member of the public who has contacted the center. These animals represent the following major species: California sea lion, northern elephant seal, Pacific harbor seal, northern fur seal, and the southern sea otter. On a few occasions, the Marine Mammal Center has taken in Guadeloupe fur seals, Steller sea lions, and bottlenose/Pacific white-sided dolphins. The only non-mammals that the center takes in are sea turtles. The research team consists of veterinarians
Mammal classification and the new McKenna/Bell classifications of mammals. Extinct groups are represented by †. Several important fossil mammal discoveries have been made that have led researchers to question many of the relationships proposed by McKenna and Bell (1997). Additionally, researchers are subjecting taxonomic hypotheses to more rigorous cladistic analyses of early mammal fossils. Luo et al. (2002) summarized existing ideas and proposed new ideas of relationships among mammals at the most basal level. They argued that the term mammal should be defined based on characters (especially the dentary-squamosal jaw articulation) instead of a crown-based definition (the group that contains most recent