Bohaiornithidae of sexual dimorphism, with the feathers being used by male members of a species for courtship display. A subadult specimen of an indeterminate bohaiornithid described in 2017 preserved feathers on various parts of the head and body which were analyzed and determined to have been iridescent in life. A referred adult specimen of "Bohaiornis" was preserved with a several rocks concentrated in the stomach region. Rocks in the stomach of birds and other animals are often believed to be gastroliths swallowed to assist in the digestion of plant material. However, the rocks apparently swallowed by this specimen are much larger,
What Is to Be Done? What Is to Be Done? What Is To Be Done? Burning Questions of Our Movement () is a political pamphlet written by the Russian revolutionary Vladimir Lenin (credited as N. Lenin) in 1901 and published in 1902. Lenin said that the article represented "a skeleton plan to be developed in greater detail in a pamphlet now in preparation for print". Its title is inspired by the novel of the same name by the 19th century Russian revolutionary Nikolai Chernyshevsky. In "What Is to Be Done?", Lenin argues that the working class will not spontaneously become political simply by fighting economic