T. Rex and the Crater of Doom the Brazos river that a tsunami has swept across the Gulf of Mexico millions of years earlier. The discovery was made thanks to a graduate student named Alan Hildebrand that notified Alvarez of the evidence of a crater on the Yucatan peninsula, which had never been published in the scientific literature by the Mexican petroleum geologists that had found it. The age of the crater needed to be determined if it was going to be a candidate for the KT boundary impact, but access to the region was limited by the crater being buried over time and the core samples
Gruithuisen (crater) the edge of the highland peninsula between the two maria is a domed mountainous rise that is designated Mons Gruithuisen Gamma (γ). Just to the east of this feature is another mountainous rise named Mons Gruithuisen Delta (δ). Northwest of Gruithuisen crater is concentrated cluster of several craterlets, which was most likely formed from a single body that broke up just prior to impact. By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Gruithuisen. Gruithuisen (crater) Gruithuisen is a lunar impact crater that lies on