Mammals
Tour the first floor in a clockwise direction, beginning with the Mammals hall. It’s an impressive place to start because you’re immediately surrounded by lots of big animals. To your left is a two-story display with a life-size moose, white rhino, panda bear, and a score of other creatures; to your right is a similar case with walrus, chimpanzees, horned sheep, and more. Hanging from the ceiling above you is a life-size manatee mother and child, as if they were swimming above you in a stream.
The museum’s strength is its ability to explain clearly the scientific basis for the things you’re seeing. In the case of mammals, large panels near the hall entrance explain the characteristics that distinguish mammals from other creatures. Specifically, mammals have:
- Hair
- Mothers that nurse their young with milk
- Special small ear bones that amplify sound
- Warm-blooded, self-regulating body temperatures
- Brains with a neocortex, used to process complex information such as spatial reasoning, social interactions, and speech
The Mammals hall focuses on the first four characteristics. You’ll see more about brain development in the Hall of Human Origins later on this floor.
The story of mammals would be impossible to tell without referencing evolution, so the museum introduces here the six elements of the evolutionary process: environmental change, natural selection, adaptation, innovation, diversification, and extinction. As you view the exhibits in this hall, you’ll see signs explaining the relevant part of the evolutionary process on display.
For example, in the Africa scenes a few feet away, you’ll see how, as the continent’s landscape changed from tree-filled rainforest to savannah, giraffe necks got longer in order to reach the leaves on the remaining, higher trees. (The same lessons are continued farther down the hall, as the animals on exhibit move to South America, Australia, and North America.)
The first group of mammals you’ll see are from Africa, and these animals are used to illustrate the “adaptation” phase of evolution. Before that gets started, though, you’ll see a pair of lions attacking an African buffalo, a stark reminder that all animals are food for something else in the great circle of life.
On your right is a Sahara Desert display, showing how mammals have adapted to the minimal water and high heat of the desert. The fennecs, a type of small fox, seen here are nocturnal. By napping in underground burrows that are 40 degrees cooler than the desert, they can avoid the hottest part of the day. Fennecs also have large ears – about a third the size of their entire body – and blood vessels there help dissipate heat. Huge ears are also helpful in detecting the movement of prey at night.
Also in this scene are Scimitar-horned oryx and Dama gazelles. Instead of burrowing, these hooved animals have adapted to the desert heat with tall, slender legs to keep their bodies away from the scorching sand; and horns and special blood vessels in their long noses to keep their heads and brains cool.
The next scene is the Savanna. On these wide-open plains, an animal’s biggest concern isn’t heat – it’s that predators can see for long distances in every direction, allowing them to spot and stalk prey more easily. In response, animals have developed three basic defenses: fight back, as the sable antelope does with its curved horns; run faster than what’s chasing it, as the gazelles; or outsmart your prey, as shown by the zebra in the Savanna Waterhole display across the walkway. When packed together in a moving herd, the zebras’ stripes make it hard for a predator to focus on a single individual, which increases the herd’s survival rate.
Two other interesting things to see in the Africa area: a giant termite mound is used to illustrate how aardvarks and pangolins have evolved to eat these biting insects, with tough hides, big claws for digging, and tongues of up to 2 feet in length; and in the Rainforest display at the end of the room, how the horns of the deer-like bongo are curved backward to avoid getting stuck in brush and low-hanging branches.
Unofficial Tip: Regarding evolutionary diversification, the museum notes that there are over 4,000 species of rodent, but fewer than 20 species of aardvark.
Just beyond the Rainforest section is a hallway. To the left are mammals from Australia and South America; to the right is North America. We’ll cover these shortly. In front of you, though, is a tall display showing the family tree of morganucodon oehleri, the common ancestor of all mammals, from around 210 million years ago. A small bronze cast of m. oehleri is nearby; it’s the thing that looks like a shiny mouse. The museum has named it Morgie and decided it’s a she.
The odd thing about the Morgie display is that the museum doesn’t seem to say why it thinks she’s the oldest mammal ancestor. We’ll say up front that the process of identifying the “first” mammal is like identifying the “first” rock and roll band: even professional musicians will have slightly different criteria, and within the same criterion, there’ll be debate as to whether someone’s music exhibits enough of whatever it is to count.
Here’s what we’ve found with Morgie: Remember those displays back at the entrance to the Mammals hall – the ones that said something about tiny ear bones and mother’s milk? Morgie is the oldest known fossil that shows the characteristics of a mammal’s ear bones. It’s a sort of in-between model of ear bone, with some reptilian characteristics and some mammalian, but this seems to be the starting point for mammals. Also, the jaw bones that we have from Morgie indicate that she was born toothless and kept her adult teeth her entire life - the kind of thing you see with mammals who feed on milk from their mothers. Plus, from the fossil record, we know Morgie had hair.
Is this conclusive proof? Not for everyone. Besides the in-between ear bones, there’s some evidence that m. oehleri laid eggs rather instead of giving birth to live young, and laying eggs is very rare in the mammalian world (only about 1 per 1,000 species of mammals do, such as the platypus). Because of that, and the in-between nature of the ear bones, some scientists classify Morgie as a mammaliaform, or mammal-like animal, not actually a mammal.
All of that said, the natural evolution of even small mammals is usually a process so slow that it’s difficult to comprehend. If you’re a museum that has to answer the question “What was the first mammal”, Morgie is a good response.
Beyond the Morgie display is the Evolution Theater, showing a 6-minute movie about evolution. The film focuses primarily on the interaction of environmental change and natural selection, with a couple of cameos by Morgie. Limited seating is provided. The movie isn’t mandatory for understanding evolution or any part of the museum, and can be skipped.
To the left of the Evolution Theater are displays with mammals from Australia and South America.
Unofficial Tip: If you’re touring the museum for half a day or less, skip Australia and South America and head to your right, through the North America mammals and to the Human Origins hall.
