Tetragramma donaldtrumpi is a species of fossil sea urchins discovered and identified by William R. Thompson Jr. in 2016. The specimen locality is from the Lower Cretaceous, Trinity Group, of the Glen Rose Formation near Fischer, Texas, in the United States.
Based from the fossils discovered of Tetragramma donaldtrumpi, the species is known to have been about in size and round in shape, with the appearance of a Life Savers candy. The genus Tetragramma is known from the Upper Jurassic (Oxfordian) to the Upper Cretaceous (Turonian).
Thompson named the species to honor then Republican presidential nominee Donald Trump. A paleontology lab at the University of Texas at Austin holds a fossil of the species, along with 45 other species.