The anterior portion of the upper and lower jaw are curved upward, creating a distinct beak that is thought to have allowed them to be specialized grazers.

[2] This finding also shows that part of the Rio do Rasto Formation in Brazil can now be correlated with deposits in India, Malawi, Mozambique, South Africa, Tanzania, Zambia, and Zimbabwe.

Apart from size, E. mahalanobisi also has a pointed snout with only a single, low longitudinal ridge (compared to three raised crests on E. bathystoma), a narrow pineal foramen lacking a bony boss or collar, and a flat prefrontal bone.

[5] Although initially discovered in and thought to characterise separate regions, their ranges have since been found to overlap in eastern Africa, with potentially all three present in Mozambique.

[9] Endothiodon was first described by Richard Owen in 1876 from fossils discovered in the Karoo region of Beaufort Group, South Africa based on a skull and mandible.

[2] Four main endothiodont genera, Endothiodon, Esoterodon, Endogomphodon, and Emydochampsa, were variably utilised and separated under the subfamily Endothiodontinae.

Compared to the other three species, it had a smaller inferred adult size, only a single low longitudinal ridge on the snout, a more elongated pineal foramen situated on a low boss located midway on the intertemporal bar in front of instead of surrounding the pineal foramen, and a slender dentary symphysis.

It is distinguished from other Endothiodon based on the lack of a pineal boss and the presence of a pair of tusks lateral to the tooth row.

The cladogram below shows and simplifies the results of Angielczyk et al. (2017) to highlight the phylogenetic relationships of the genus Endothiodon relative to other dicynodont species and clades:[12] "Eodicynodon" oelofseni [a] Eodicynodon Colobodectes Lanthanostegus Eosimops Robertia Diictodon Prosictodon Pristerodon Brachyprosopus Pristerodon Niassodon Abajudon Endothiodon Emydopoidea Bidentalia The intrarelationships of Endothiodon were phylogenetically tested for the first time in 2024 by Maharaj and colleagues in 2024 using a specimen-level analysis of individual specimens assigned to E. bathystoma, E. mahalanobisi, E. tolani and E. uniseries.

Their results found consistent clades corresponding to the first three species, whilst specimens assigned to E. uniseries were spread within E. bathystoma, supporting their synonymy.

A simplified cladogram from Maharaj et al. (2024) following their proposed taxonomy is presented below, showing the relationships of Endothiodon species:[1] Patranomodon Diictodon Niassodon Abajudon E. mahalanobisi E. tolani E. bathystoma In adult Endothiodons the lower jaw teeth are pear shaped in cross section, compressed distolaterally, and has posterior serrated edges while the upper jaw teeth have anterior serrated edges.

It is possible that the different tooth morphology might be due to a change in diet from insectivorous or omnivorous as a juvenile to herbivorous as an adult.

[10] The Karoo region is characteristic of siltstones that are fine-to medium- or coarse-grained, dark or greenish grey, and very finely crossbedded.

[15] In 1997 the first specimen of E. mahalanobisi was found in the Kundaram Formation in the north-western part of Pranhita-Godavari valley near Golet in Adilabad district, Andhra Pradesh, India.

[9] In addition to Africa and India, Endothiodon is also known from the Morro Pelado Member of Rio do Rasto Formation in the Paraná Basin, Brazil.

Instead, it is now thought that Endothiodon inhabited the dense riverine vegetation and would crop foliage with its beak before processing it with its specialized and extensive oral cavity.