Multituberculate

Part of speech: noun, adjective

Definitions

1. Describing or belonging to an extinct order of small, rodent-like mammals that lived alongside the dinosaurs and were known for their multiple-cusped teeth
2. Relating to an extinct group of early mammals characterized by grooved, multi-cusped molars and a rodent-like appearance
3. Of or pertaining to a long-extinct order of small mammals whose teeth bore several rows of cusps and whose lineage stretched back into the Mesozoic

Etymology: Multituberculate is a compound built from "multi-", meaning many, and "tuberculate", which describes something bearing small knobs or tubercles. The name points directly at the teeth. Paleontologists gave these animals the label because their molars carry rows of raised cusps, a feature that sets them apart from most other early mammals. The word works as both a noun and an adjective. As a noun it names a member of the extinct order, and as an adjective it describes the group or anything belonging to it. Because the animals were tiny and their remains are mostly teeth and jaw fragments, the tooth shape gave scientists the most reliable clue to who they were.