In this article, Phillips has anargument that transference errors are dependent on a mammal’s body size andlifespans, causing a rise in previous estimates of interordinal divergencetimes. He also suggests that the majority of interordinal divergences arepositioned after the KPg boundary. Although Phillips does believe in using theexplosive model to post the majority of interordinal diversification after theKPg mass extinction, he also presented the idea that emersions of the Xenarthra,Afrotheria, Euarchontoglires, and Laurasiatheria lineages came from the softexplosive model. Assumptions were formed from using the explosive mode,believing that extinctions were caused by both interordinal and intraordinaldiversification after the KPg mass, making morphological cladistic studies ofCretaceous eutherians and crown Placentalia to become segregated from oneanother. In the methods section of this article, thefollowing things were calculated: number of lineages, number of new lineages,and number of new lineages per million years for each stage, percentageincrease or decrease across stage boundary, which were are all based onPhillips’ preferred timetree using Meredith’s DNA supermatrix which contained169 species and 27 calibrations.
The 2010 version of the geological time scalewas used to find the rates for dR27b and Mer82c, while the 2014 versioncalculated the Emer15 rates. These authors decided to use different versions ofthe geologic time scale. Emer15 recorded two speciation events that occurrednear the end of the Lutetian that were unrelated to Meredith’s taxon sampling,which included deep splits in Soricidae and Emballonuridae which were notincluded in the analysesIn conclusion, Ghost lineages werepresumed to exist without having any fossil records, while zombie lineages werefound to have fossil records that are not compatible with the timetree dates.Ghost lineages are expected to be products of incomplete fossil records, whilezombie lineages are only possible with inaccurate minimum ages of fossils orwhen fossils have not been assigned to their proper taxonomic group .Eventhough there is a great number of zombie lineages that contradict the fossil record,Phillips’ timetree does contain various ghost lineages that are older than thefossil record, having fewer incompatibilities compared to most other studies.Fossils are unable to provide any conclusive evidence related to the ancestryof extant mammals , due to Cretaceous and Paleocene fossils and modernplacental lineages being unrelated.