Labocania aguillonae

Dinopedia ^ | circa September 2024 | editors / unattributed

[SunkenCiv]

Because Labocania is based on fragmentary material, its affinities were uncertain. Molnar noted certain similarities between Labocania and tyrannosaurids, especially in the form of the ischium which features a low triangular obturator process and a circular lateral scar on the upper end, but he did not assign Labocania to any family, placing it as "Theropoda incertae sedis". Molnar especially compared Labocania with Indosaurus and "Chilantaisaurus" maortuensis, later made the separate genus Shaochilong. Labocania was considered as a possible tyrannosauroid in the 2004 review of the group by Thomas R. Holtz, Jr., who, however, pointed out that the similarities with the Tyrannosauridae were shared with the Coelurosauria in general — no tyrannosauroid synapomorphies were present — and that Labocania also showed some abelisaurid traits such as the thick frontals and a reclining quadrate. On the other hand, the L-shaped chevron and the flattened outer side of the second metatarsal indicated a position in the Tetanurae.

A 2024 study has named a second species of Labocania, which is much less fragmentary and gives a much better placement of the genus. The new species, L. aguillonae, was described with a partial femur, metatarsal, and other fragments across the body. The morphology of the specimen solidifies the genus's classification as a tyrannosaurine tyrannosaurid in the tribe Teratophoneini. The current closest genera to Labocania is Teratophoneus, Dynamoterror, and Lythronax.[1] Interestingly, the phylogeny places Nanotyrannus as a non-tyrannosaurine tyrannosaurid, despite it commonly being accepted as a junior synonym of Tyrannosaurus. Alioramini, a tribe usually put within Tyrannosaurinae, was placed outside of Tyrannosauridae as a sister taxon. Results of the phylogenetic analysis are shown below:

[JimRed]

More dead critters...

[SunkenCiv]

Labocania aguillonae didn’t kill itself... ;^)