The Specimen Collection at the Naturalist Center

The specimens on display at the Naturalist Center hail primarily from old exhibits, the U.S. Fish and Wildlife Service when they confiscate animals, and people who stumble upon them and donate them to the museum.

Affectionately known as Poop Central by the center's younger visitors, one shelf carries a selection of scat, both real and fossilized from a variety of animals <name animals they have>. The non-fossilized scat specimens have been frozen to kill pathogens. Scat samples present useful information about the animal, such as its diet (undigested parts of plant matter, insects, or other animals) and help with animal identification.

Older specimens at the center live behind enclosed glass display cases, since taxidermists used arsenic to preserve animals up until the 1960s. Only direct contact with these stuffed animals pose a risk to people's health. Today, specimens are preserved: <discuss method>

Columbian mammoths were almost twice as big as their better-known relatives, the wooly mammoth. The Naturalist Center has two fossilized Columbian mammoth teeth, each almost a foot long, on display. A construction worker discovered one of them at the San Francisco Transbay Transit Center construction site in 2012, when he noticed it was too perfect to be a rock. Mammoths were some of the last megafauna to survive, roaming the Earth 10 to 15 thousand years ago during the Pleistocene Era.

The Anthropology case contains a selection of skull casts—and one real one—of humans during various stages of evolution.

The Center also has Pacific walrus skulls, both a real one and a cast version. With adult males weighing up to 2,000 kg and tusks that can grow up to a meter long, the average walrus eats 6,000 clams a day. The center also has a dire wolf skull, popular with fans of the HBO series, Game of Thrones, who are surprised to learn dire wolves were real. A relative of wolves, dire wolves roamed the Earth during the Pleistocene Era at the same time as mammoths.