Saint Bathans mammal facts for kids

The Saint Bathans mammal was an ancient, unnamed mammal. It lived in New Zealand a long, long time ago, during a period called the Early Miocene. This was about 16 to 19 million years ago! It was part of a group of ancient animals called the St Bathans fauna.

This mammal is special because it was a very old type of mammal. It was not a placental mammal (like humans or dogs) or a marsupial (like kangaroos). It also shows that land mammals that couldn't fly once lived in Zealandia, which is the continent New Zealand is part of. This is different from today's New Zealand. Now, only bats and seals are the native mammals. All other land mammals were brought there by people.

How We Found It

Scientists have found three pieces of the Saint Bathans mammal. These pieces are kept at the Museum of New Zealand Te Papa Tongarewa. They are called NMNZ S.40958, NMNZ S.41866, and NMNZ S.42214. The first two are parts of its lower jaw. The third is a piece of its leg bone, called a femur.

These fossils were found in a place called Saint Bathans in 1978. They were in a rock layer known as the Bannockburn Formation. Scientists first described these fossils in 2006.

What It Looked Like

Since we only have a few bone pieces, it's hard to know exactly what the Saint Bathans mammal looked like. We have parts of its lower jaw and a leg bone.

Its Jaw and Teeth

The jaw pieces found don't have teeth in them. But they have deep holes where teeth used to be. This means the animal had teeth when it was alive. Its lower jaw had a long, joined front part. It also had a lower incisor tooth that stuck out. Scientists think it had one incisor, one canine (a pointy tooth), and two premolars (flat teeth for grinding).

Its Leg Bone

The leg bone, or femur, has a round top part called the femoral head. The part connecting it to the main bone, the femur neck, isn't very clear. It points slightly upwards and inwards. There's a clear dip between the head and a bumpy part called the greater trochanter.

Scientists believe this animal walked with a "semi-sprawling" stance. This means its legs stuck out to the sides more than in modern mammals. But they didn't stick out as much as in monotremes, like the platypus.

Where It Fits in the Family Tree

Because we only have a few bones, it's very tricky to figure out where this mammal fits in the big family tree of all mammals. In 2006, scientists thought it was more advanced than some very old mammals. But it was not as advanced as others. Since then, our understanding of ancient mammals has changed a lot. New studies might be needed to place it correctly.

Its Ancient Home

The area where the Saint Bathans mammal lived was very different from today's New Zealand. It was a warm place, like a subtropical lakeside. It was surrounded by peat–swamps with lots of plants.

Plants of Its Time

Many types of trees grew there. These included Casuarinas, araucarias, podocarps, eucalypts, palm trees, and southern beech trees.

Other Animals It Lived With

Just like today, birds were common in ancient New Zealand. There were early moas and adzebills. Also, there were different kinds of waterfowl, flamingos, rails, herons, and parrots. Even an early kiwi bird, called Proapteryx, lived there.

But unlike modern New Zealand, there were many different reptiles and amphibians. Besides an early tuatara, there were also meiolaniid and pleurodire turtles. It's even possible there were mekosuchine crocodiles and snakes.

Besides the Saint Bathans mammal, other mammals lived there too. These included mystacine bats, which are still found in New Zealand today. These bats likely looked for food on the ground, just like the Saint Bathans mammal might have done. Other types of bats, like vesper bats, also lived in this ancient environment.