Hoplophoneus enters the LRT alongside Smilodon

No surprises here.
Hoplophoneus primaevus (Leidy and Owen 1851, Cope 1874, Late Eocene to Early Oligocene, 30mya) is a smaller sister to Smilodon, the sabertoothed wolverine/weasel (too early to be a cat) in the large reptile tree (LRT, 2286 taxa).

Note the extremely narrow (in front view) canines. These seem like they would be fragile when exposed. The upturned mandible tip is doing its best to protect the teeth when sheathed, but that added depth requires a wider swing of the jaws in order to perforate anything.

Figure 1. Skull of Hoplophoneus in four views. Note the extremely narrow (as seen from the front) canines. These seem like they would be fragile when exposed. The upturned mandible tip is doing its best to protect the teeth when sheathed, but that requires a wider swing of the jaws in order to perforate anything.
This was a private specimen when photographed. Not sure where it is today. Let us all know if it has a museum number now.

By contrast, Barrett 2016
considered Hoplophoneus a relative of the cat, Nimravus, due to taxon exclusion. Barrett wrote, ““The Nimravidae is a family of extinct, superficially “cat-like” carnivores, most of which exhibit saber-tooth dentition.”

The LRT does not confirm Barrett’s hypothesis of interrelationships. Some sabertooth taxa nest outside of the cats. In the LRT Hopolophoenus, Smilodon and civets all converged with cats. In the LRT dogs and wolves are closer to cats than Hoplophoneus.

That’s why it is SO important to test a wide gamut of taxa. The LRT is fully resolved as it separates convergent taxa and lumps related taxa.

Figure 2. Skeleton of Hoplophoneus. Manus (left) and pes (right) provided with PILs.

Hoplophoneus primaevus
(Leidy and Owen 1851, Cope 1874, Late Eocene to Early Oligocene, 30mya) is a earlier sister and thus a possible ancestor to Smilodon in the LRT.

Dinictis, a true sabercat, enters the LRT tomorrow.

References
Barrett PZ 2016. Taxonomic and systematic revisions to the North American Nimravidae (Mammalia, Carnivora) PeerJ 4:e1658 https://doi.org/10.7717/peerj.1658
Cope ED 1874. Report upon vertebrate fossils discovered in New Mexico, with descriptions of new species. Chief of Engineers Annual Report, Appendix, S. 589-606, U.S. Government Printing Office, Washington.
Leidy J and Owen R 1851. Academy of Natural Sciences, Philadelphia Proceedings 239:

wiki/Proailurus
wiki/Smilodon
wiki/Amphicynodon
wiki/Machaeroides
wiki/Hoplophoneus