Certain materials are “classic” in Montessori classrooms. The external parts of the vertebrate animals are one of those essential materials. This set traditionally has a horse as the example of a mammal, and almost all commercially available card sets for study of the vertebrates uses the horse.

My question is “why?” Unless we try to understand Maria Montessori’s purpose in the design of her materials, we can easily get caught in a web of tradition that keeps us from serving children’s learning needs to the best of our ability.

Here is my best guess on the horse as the mammal example. The horse was present in the lives of children all over the world until about 1920. It didn’t matter if they lived in a city or on a farm. When Maria Montessori first created her materials, the mammal that most children would see in their everyday lives was a horse. That has changed for most children. The horse is still used for transportation in some rural areas, but this animal is now more likely to be seen in a hobby or leisure situation. Most children in the United States do not see a live horse with any regularity.

What mammals do children see today? Dogs and cats would likely top the list. Classroom pets like gerbils, guinea pigs, or hamsters are common enough. Why don’t we use one of these for the example mammal? Children are more likely to be interested in learning about an animal they can experience, and learning about the care of that animal may also be very relevant to them.

Should we get rid of the “Parts of a Horse” cards? Probably not. There is nothing to keep you from having additional examples after you study the first one. Some children do see horses regularly and will be very interested in learning their parts.  Others could have their horizons expanded by seeing additional examples.

What about the other vertebrate examples? The frog as an amphibian is about as good an example as a newt or salamander. The latter two are harder to observe in nature, but they can be kept in the classroom, probably with fewer problems than keeping a frog. It depends on the frog. Some can be escape artists – voice of experience here.

The turtle probably became the reptile of choice because it is less intimidating than a snake or a lizard, but a lizard gives a better look at the basic reptile body. Turtles are quite derived – they have changed a lot from their ancestors. They still have the scaly skin and lay eggs, so they work.

At some point, the crocodilians (crocodiles, alligators, caimans) need their own category. They are more closely related to birds than they are to the squamates (snakes and lizards). Both crocodilians and birds belong to the archosaur branch of the reptiles. Now that this is known, even children’s books point out the similarities. Both birds and crocodilians make nests, vocalize, and care for their young. They both have four-chambered hearts as well.

These two are closer cousins than either is to a lizard.

Using a perching bird for the example of the feathered vertebrates works well. It is worth asking, however, what birds children see. Maybe they see chickens on the school grounds. Maybe it is song birds that come to a feeder. Maybe it is a pigeon in the city. Maybe it is caged bird in the classroom. Going back to a real bird is an important step to make learning the parts into living knowledge.

Finally, the whole collection of vertebrates should be called the groups of vertebrates, NOT the classes of vertebrates. Biologists haven’t placed fishes into a single class since about 1850. The former classes were jawless fishes, cartilaginous fishes, ray-finned fishes, and lobe-finned fishes. That’s much more than children need at the beginning of their studies. The classroom fish tank can house valuable examples of ray-finned fishes, and that’s a great launching point. After all, ray-finned fishes are more than 99% of all fishes.

You can look that fish in the eye and say to it, “You and I shared a common ancestor, back in the beginning of the Paleozoic Era.” You can tell the amphibian that you shared a common ancestor with it back in the Devonian Period. Not long (geologically speaking) after that in the Carboniferous Period you shared a common ancestor with birds and reptiles, the other animals that reproduce on dry land, which are known as the amniotes.

It’s all in the ancestors and the great evolutionary journey. Enjoy the trip.