Mega-authorship implications: How many scientists can fit into one cell?

The past 20 years has seen a significant increase in articles with 500 or more authors. This increase has presented problems in terms of determining true authorship versus other types of contribution, issues with database metadata and data output, and publication length. Using items with 500+ authors deemed as mega-author titles, a total of 5,533 mega-author items were identified using InCites. Metadata about the items was then gathered from Web of Science and Scopus. Close examination of these items found that the vast majority of these covered physics topics, with medicine a far distant second place and only minor representation from other science fields. This mega-authorship saw significant events that appear to correspond to similar events in the Large Hadron Collider's timeline, indicating that the projects for the collider are driving this heavy output. Some solutions are offered for the problems resulting from this phenomenon, partially driven by recommendations from the International Committee of Medical Journal Editors.