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
Ammonius (crater) Ammonius (crater) Ammonius is a bowl-shaped lunar impact crater with a slightly raised rim and is named after It is located on the floor of the walled plain Ptolemaeus, about 30 kilometers northeast of the crater midpoint. Just to the north on the lava-flooded floor of Ptolemaeus is a relatively prominent "ghost" crater: the discernible buried rim of a pre-existing crater. The diameter of this ghost crater is nearly double that of Ammonius, and is currently identified as Ptolemaeus B. The crater is named after Ammonius Hermiae. In the past this crater was identified as Ptolemaeus A, before being named