Taihangosuchus

The skull of Taihangosuchus is around 18 centimetres (7.1 in) long in the holotype. The part of the maxilla in front of the antorbital fenestra is very short, and the antorbital fossa is longer than the orbit. The scapula, humerus, and ulna are all similar in length. The postacetabular process (rear part) of the ilium is truncated, instead of pointed like in other gracilisuchids. There is a robust ridge along the dorsal margin of this region for the origin of the caudofemoralis brevis muscle.^[1]

Several bone fragments are identifiable in the ribcage of the paratype specimen. The most identifiable elements are osteoderms of various sizes. The morphology of these osteoderms is most similar to those of Halazhaisuchus (also known from the Ermaying Formation, albeit a lower part) and Batrachotomus. As such, this may be an indication that Taihangosuchus preyed on animals similar to these. Alternatively, they may derive from an unknown archosaur or even other individuals of Taihangosuchus.^[1]

In their phylogenetic analyses, Wu et al. (2025) recovered Taihangosuchus as a member of the early-diverging pseudosuchian clade Gracilisuchidae. Their results placed it diverging after the similarly aged Chinese Turfanosuchus, also dating to the Anisian age,^[2] but before the clade formed by the Chinese Yonghesuchus and Argentinian Gracilisuchus. These results are congruent with the chronostratigraphic (relating to rock layers over time) occurrences of these genera, with older genera diverging first, and younger (more recent) genera diverging later. This may imply that gracilisuchids originated in the landmass Laurasia, diversifying in Asia before spreading elsewhere (Gondwana). While not included in the description of Taihangosuchus, the description of the Brazilian gracilisuchid Parvosuchus by Müller (2024) recovered a similar topology, with Parvosuchus in a derived position close to Gracilisuchus, to which it is similar in age.^[3] A cladogram following Wu et al. (2025) is displayed below:^[1]

Pseudosuchia	†Erpetosuchidae †Parringtonia †Erpetosuchus †Gracilisuchidae †Turfanosuchus †Taihangosuchus †Gracilisuchus †Yonghesuchus Suchia †Aetosauria †Ornithosuchidae †Ticinosuchus Paracrocodylomorpha †Poposauroidea Loricata