The Arkansia plant constitutes the most completely known Cheirolepidiaceae plant to date. Our phylogenetic analyses support Cheirolepidiaceae as a transitional lineage between voltzialean and living conifers, reflected in their ovuliferous complex morphology, which shows intermediate traits between voltziacean voltzialeans and extant taxa. Age estimates of deep nodes of conifer phylogeny are broadly congruent with the fossil record, suggesting a long-lasting stem group and an origin of crown-group conifers in the Late Triassic.
Andruchow-Colombo et al. (Sat,) studied this question.