Morganucodonta

Morganucodonta ("Glamorgan teeth") is an extinct order of early mammal-like animals called Mammaliaformes. This group includes modern crown-group mammals and their close relatives. Fossils of these ancient creatures have been discovered in many places, including Southern Africa, Western Europe, North America, India, and China.

Scientists think morganucodontans probably ate insects and were active at night. Some species grew quite large and may have eaten other animals. Living at night might have been a special way for the first mammals to stay safe, because bigger predators were usually active during the day. This idea is called the nocturnal bottleneck.

Anatomy and biology

Morganucodontans had a special way their jaws worked, with two joints connecting the top and bottom parts. This meant they kept some extra bones in their lower jaw that most animals today do not have. These extra bones were inside the jaw.

They had different kinds of teeth, like incisors, canines, molars, and premolars, which helped them eat. Scientists think they ate insects and small animals. Some morganucodontans were larger than others and had bigger teeth for catching bigger food. Their teeth fit together in special ways when they chewed.

Classification

Morganucodontans had a special jaw joint like mammals. Some scientists thought they were mammals, but most scientists today call them "mammaliaformes." This means they are closely related to mammals but not exactly the same group.