Trimucrodon

Trimucrodon (meaning "three-pointed tooth") is a genus of herbivorous dinosaur from the Late Jurassic or Early Cretaceous of what is now Portugal. It has been classified as a basal ornithischian, but is a nomen dubium: it is a "tooth genus" known only from its teeth.

Between 1962 and 1967 German zoologist and paleontologist Georg Krusat uncovered mammal fossils near Porto Dinheiro, Lourinha, in layers of the Camadas de Alcobaça Formation. This rock unit was then seen as dating from the Kimmeridgian stage, around 150 to 155 million years ago but was later suggested to date to the Cretaceous (early Berriasian stage), about 145 million years old. One small tooth was recognised by Richard A. Thulborn as dinosaurian instead of mammalian and in 1973 he described and named it Trimucrodon cuneatus; the paper was not published until 1975. The generic name is derived from Latin tri~, "three", and mucro, "dagger point", and Greek odous, "tooth". The specific name means "wedge-shaped" in Latin. The holotype tooth is part of the collection of the Lehrstuhl fur Paläontologie, Freie Universität at Berlin but has no published inventory number. Some other Portuguese teeth from the formation were referred to the species.

Thulborne originally classified Trimucrodon as a member of the Fabrosauridae. José Ignacio Ruiz-Omeñaca in 2001 placed it within the Heterodontosauridae. However, recent authors have considered it a basal ornthischian of uncertain affiliations.