Ornithothoraces Ornithothoraces Ornithothoraces is a group of avialans that includes all enantiornithes ("opposite birds") and the euornithes ("true birds"), which includes modern birds and their closest ancestors. The name Ornithothoraces means "bird thoraxes". This refers to the modern, highly advanced anatomy of the thorax that gave the ornithothoracines superior flight capability compared with more primitive avialans. This anatomy includes a large, keeled breastbone, elongated coracoids and a modified glenoid joint in the shoulder, and a semi-rigid rib cage. The earliest known members of the group are the enantiornitheans "Protopteryx fengningensis", "Eopengornis martini", and "Cruralispennia multidonta", as well as the euornithine "Archaeornithura
Pan American Association of Anatomy Pan American Association of Anatomy The Pan American Association of Anatomy (PAA) is a public, nonprofit, scientific organization that brings together professionals engaged in the study of Anatomy and related sciences in the American continent. The Pan American Association of Anatomy (PAA) was created in July 1966 in Mexico City at the 1st Pan American Congress of Anatomy, which was held together with the 3rd National Congress of the Mexican Society of Anatomy. Its mentor was the Prof. Dr. Liberato J. A. Didio. The need for a Pan American Association of Anatomy was proposed by Prof. Di Dio during the