metaaramiids

Metaaramiids are an extinct group of mammals that lived during the Late Cretaceous period, approximately 70-66 million years ago. They are known from fossil remains found in what is now North America. Metaaramiids belong to the order Multituberculata, which is often referred to as the most successful mammalian order of the Mesozoic era, both in terms of diversity and longevity.

The name "Metaaramiids" is derived from the Greek word "meta," meaning beyond, and "Aramiids," referring to another group of multituberculates. This name reflects the evolutionary position of metaaramiids as being more derived than aramiids. Metaaramiids are characterized by several distinctive dental features, including a reduced number of teeth and the presence of unique cusps on their molar teeth. These adaptations suggest that they had a specialized diet, possibly consisting of hard or tough plant materials.

Metaaramiids were small mammals, with most species estimated to have weighed between 100 and 500 grams. They were likely arboreal, living in trees, based on their small size and dental adaptations. The fossil record suggests that metaaramiids were relatively rare compared to other multituberculates, and their distribution was limited to North America.

The most well-known genus of metaaramiids is Metaaramius, which is known from several well-preserved skulls and jaws. Metaaramiids went extinct at the end of the Cretaceous period, along with many other groups of animals, including the non-avian dinosaurs. Their extinction marked the end of the multituberculates as a dominant group of mammals, although some related groups persisted into the Cenozoic era.

In summary, metaaramiids were a specialized group of multituberculate mammals that lived during the Late Cretaceous period. Their unique dental adaptations and small size suggest that they occupied a specific ecological niche, possibly as arboreal herbivores. Their extinction at the end of the Cretaceous period marked the end of an era for multituberculates as a dominant group of mammals.