The impact of unstable taxa in Coelurosaurian phylogeny and resampling support measures for parsimony analysis

POL, DIEGO; GOLOBOFF, PABLO

BULLETIN OF THE AMERICAN MUSEUM OF NATURAL HISTORY

AMER MUSEUM NATURAL HISTORY

Lugar: New York; Año: 2020 p. 98 - 115

0003-0090

Paleontologicaldatasets inherently have large amounts of missing entries that result inmultiple most parsimonious trees. Highly incomplete and conflictive taxaproduce a collapsed strict consensus and several methods have been developedfor identifying these unstable or rogue taxa in optimal trees derived fromphylogenetic analyses. In addition to decreasing consensus resolution, incompleteor conflictive taxa can also severely affect the support values of phylogeneticanalysis in paleontological datasets. Here, we explore a protocol implemented inTNT scripts for the identification of taxa that decrease jackknife supportvalues in parsimony analysis. The identified taxa are excluded from majorityrule jackknife trees, revealing the nodes that have either low or high supportirrespective of the uncertainties in the placement of unstable taxa. A recentlypublished dataset of coelurosaur relationships based on 164 taxa and 853characters is explored using this protocol; our protocol detects a total of 40unstable taxa as the most influential in obscuring nodal support. Major cladesthat are well supported in the reduced jackknife tree include Coelurosauria,Maniraptoriformes, Compsognathidae, Ornithomimosauria, Alvarezsauroidea,Therizinosauroidea, Oviraptorosauria. Clades with moderate support insteadinclude Maniraptora, Pennaraptora, Paraves, Dromaeosauridae, Troodontidae, Anchiornithidae,and basal nodes of Avialae.