Hallopus
Hallopus was a prehistoric reptile, classified by O. C. Marsh in 1881 as a dinosaur, but now thought to be a pseudosuchian more closely related to crocodilians. It was a quite small animal, reaching a length of 1 m. It was redescribed as a sphenosuchian crocodylomorph. Later, it was speculated to be more derived than Sphenosuchus and near or within the Junggarsuchus + Crocodyliformes node.Phylogeny
A recent phylogenetic analysis recovered Hallopus in a clade with Macelognathus and Almadasuchus, the Hallopodidae. The Hallopodidae was recovered as the nearest sister to the Crocodyliformes and more derived than Junggarsuchus or the "sphenosuchians" whose monophyly was not supported in this analysis.
Similarly, in redescribing Macelognathus from the Morrison Formation, Göhlich et al. recognized several anatomical similarities between Macelognathus and Hallopus while also noting if the provenance of the latter was correct, they would overlap stratigraphically.
