Comparative study of fossilized lower jaws and dental structures from Jurassic mammals of England 插畫檔

This scientific plate illustrates a diverse collection of fossilized mandibles from primitive mammals that inhabited the Jurassic landscapes of England, documenting the early evolutionary radiation of mammalian dental and skeletal structures. The drawings showcase a variety of specialized jaw morphologies, ranging from slender, elongated dentary bones with numerous small, uniform teeth to more robust frameworks featuring complex, multi-cusped molars and specialized incisors. These specimens, primarily sourced from the Stonesfield Slate and Purbeck beds, reveal critical anatomical transitions such as the development of prominent coronoid processes for the attachment of powerful masticatory muscles and the emergence of heterodont dentition, where teeth are differentiated for varied functions like piercing, shearing, and grinding. By presenting these fossils at their natural size, the illustration provides a technical record of the minute yet sophisticated insectivorous and omnivorous vertebrates that coexisted with dinosaurs, highlighting the morphological diversity within lineages such as the triconodonts and multituberculates during the Middle and Late Jurassic.