New and important pennaraptoran specimens continue to be discovered on a regular basis.
Yet, with these discoveries the number of viable phylogenetic hypotheses has increased,
including ones that challenge the traditional grouping of dromaeosaurids and troodontids
within a monophyletic Deinonychosauria. This chapter will cover recent efforts to address
prevailing phylogenetic uncertainties and controversies, both between and within key
clades, including deinonychosaurian monophyly, the phylogenetic position of�…