Tissier, J.; Smith, T.
taxonomy · biogeography · range · topology · geochronology · methods
Primary 71-terminal, 102-character analysis of early perissodactyl relationships and PETM dispersal. The 56 Ma fossil sample does not itself date the crown node or total-group origin.
The earliest sampled perissodactyls occur during the PETM and imply rapid dispersal among northern landmasses, but sparse sampling and analysis-dependent stem placements leave the order’s place of origin unresolved.
claim:event:perissodactyl-radiationPETM perissodactyl records imply rapid dispersal among northern landmasses, while sparse sampling and analysis-dependent stem placements leave the order’s place of origin unresolved.
claim:taxon:perissodactylaPerissodactyla is treated as the order containing living horses, tapirs and rhinoceroses plus diverse extinct branches; basal fossil placements remain analysis-dependent.
claim:taxon:perissodactyla:taxonomyThe Perissodactyla navigation envelope uses the earliest-known basal and stem-perissodactyl records during the PETM at approximately 56 Ma as its older evidence anchor and living horses, tapirs and rhinoceroses at 0 Ma as its younger edge; it is a total-group navigation span, not a crown-node date, precisely observed origin or divergence, complete global first appearance or ancestral lineage.
claim:taxon:perissodactyla:fossil-range