In their study of the cranium
of the South American sparassodont sabertooth, Thylacosmilus, Forasieppi, MacPhee and del Pino 2019 report, “Sparassodonta is the group that includes the common ancestor of Patene and all its descendants. Undisputed records of Sparassodonta, including ones for Patene simpsoni, begin in the Early Eocene (Itaboraian) and extend through to the Pliocene (Chapadmalalan), when the last of them disappeared.”
A recent cladogram of Sparassodonta and its outgroups
(Fig. 1) was published in Babot and Forasiepi 2016 (Fig. 2). This cladogram is distinct from the large reptile tree (LRT, 1530 taxa), so no confirmation here.
Patene is known
from a tiny partial maxilla and mandible. I have not added it to the LRT. Mayulestes has just been downloaded, awaiting testing.
According to the LRT,
taxa missing from the Babot and Forasiepi tree include Vincelestes (a sister taxon to Thylacosmilus in the LRT) and a long list of other carnivorous marsupials. Hadrocodium is not included in Babot and Forasiepi. It attracts the other sabertooth, Patagosmilus (Fig. 5), as we learned earlier here.
Late note: added the same evening as the original post:
Mayulestes ferox (Fig. 1) was just now added to the LRT, and it nests at the base of the Masrasector + Borhyaena clade. Nothing else changed. Thylacosmilus is still not related to the dasyurids, including the creodonts and borhyaenids.
Babot J and Forasiepi AM 2016. Mamíferos predadores nativos del Cenozoico sudamericano: evidencias filogenéticas y paleoecológicas. Contributions del MACN 6 Historia evolutiva y paleobiogeografica de los vertebros de America del Sur. Agnolin FL et al. editors.
Forasiepi AM, MacPhee RDE and Hernandez del Pino 2019. Caudal cranium of Thylacosmilus atrox (Mammalia, Metatheria, Sparassodonta, a South American predaceous sabertooth. Bulletin of the American Museum of Natural History 433:1–64.