Herugavialis ("Horus gharial") is an extinct genus of marine gavialoid crocodilian known from the Eocene (Lutetian stage) Mokattam Formation of Egypt. It contains a single species, Herugavialis cairensis, known from thenear Cairo, Egypt. Herugavialis did not have a maxilla process within its lacrimal gland, whereas all extant (living) crocodilians do.
The species was originally described in the genus Tomistoma, which contains a single living species, the false gharial, and remained there for nearly a century, even after more comprehensive studies found it to not belong to the genus. In a 2026 study, it was moved to its own genus, Herugavialis. This genus name references the Ancient Egyptian god Horus, widely thought to be depicted in the Great Sphinx (built from the same geological formation that Herugavialis was identified from), as well as the Sphinx's lack of a nose, referencing the missing nasal region (premaxilla) of the holotype skull of Herugavialis.
Classification
In a 2018, Lee & Yates conducted a phylogenetic anlaysis simultaneously using morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data. They recovered Tomistoma cairense as a gavialoid, more basal than the last common ancestor of both the gharial (Gavialis gangeticus) and the false gharial (Tomistoma schlegelii):
Tomistoma cairense was placed in the new genus Herugavialis in 2026, acknowledging that its inclusion within Tomistoma rendered that genus paraphyletic. Herugavialis was recovered more closely related to the gharial than the false gharial, within Gavialidae. These phylogenetic results are displayed in the cladogram below:
References