User blog comment:Lord Loss/Monster Hunter Theory... Blog/@comment-6050823-20130527193820/@comment-4009941-20130528205648

Checked charts again its hard to completely determine but it looks like Akantor, Ukanlos and Tigrex base is from the ancestor Wyvern Rex. A sorta Fatalis looking ancestor that according to Capcom is currently extinct that walks like Tigrex.