Additionally, researchers are subjecting taxonomic hypotheses to more rigorous cladistic analyses of early mammal fossils. Below is the phylogeny of the Pinophyta based on cladistic analysis of molecular data. By modern cladistic reckoning, the order Primates is monophyletic. Taxa evolving seriatim cannot be dealt with by analyzing shared ancestry with cladistic methods. With the advent of a more rigorous cladistic methodology, the subclass was proven paraphyletic. "rbc"L gene sequencing and cladistic analysis of monocots had redefined the Liliales in 1995. Modern exact quantitative cladistic analyses consistently indicate that ichthyosaurs are of the Diapsida. Antelope are not a cladistic or taxonomically defined group. These hypotheses have not been confirmed by modern cladistic analysis. Therefore, phylogeneticists typically use more than one outgroup in cladistic analysis. The taxonomy is still under study in the light of new specimens and cladistic analysis. Later exact cladistic analyses are not in agreement. Such cladistic analyses have cast doubt on the validity of the Brachiosauridae. Based on this cladistic analysis, "Mahakala" suggests that the ancestral condition for dromaeosaurids is non-volant. This has led to an alternative cladistic classification, splitting the Osteichthyes into two full classes.