It is unknown whether African species were generally aquatic, semiaquatic, or terrestrial, but their potential diets suitable for bunodont dentitions include bivalves, catfish, reptiles, eggs, and carrion.

[1][3] During the 19th and 20th centuries, more species of Enhydriodon such as E. campanii were introduced and more lutrine genera with bunodont dentition such as Sivaonyx and Vishnuonyx were described, creating a particularly complicated history for the earliest-described prehistoric otter genus.

[6] He correctly introduced the idea that Enhydra was related to Enhydriodon given their bunodont dentitions, but the supposed European "branch" of the Enhydriodon genus was later reclassified by Johannes Hürzeler and Burkart Engesser into the newer genus Paludolutra in 1976, although it remained relatively obscure in the palaeontological record until later research revised its taxonomic state.

[9] In December of the same year, Jorge Morales and Pickford instead described Paludolutra as a distinct genus that might be related to Sivaonyx based on dentition convergences.

[10][11] In 2003, Lars Werdelin erected the species E. ekecaman from the Kanapoi palaeontological site of the Turkana Basin in Kenya (early Pliocene, ca.

He also declared the species "E. pattersoni ", described by R. J. G. Savage in 1978, as a nomen nudum of E. ekecaman since no type specimen or valid diagnosis was designated to it, a view supported by Morales and Pickford in December 2005.

[13][14] In 2005, Morales and Pickford sorted Enhydriodon into the newly created Enhydriodontini tribe, which they described as hosting genera of extinct bunodont otters from the Siwalik Hills and Africa including Vishnuonyx, Sivaonyx, and Paludolutra.

In 2007, Pickford synonymized the species "E. aethiopicus ", previously described by Denis Geraads et al. in 2004, to Pseudocivetta ingens, an extinct member of the Viverridae family.

[14] In a September 2022 conference by Alberto Valenciano, Morales, and Pickford (the same month as the research paper on E. omoensis), however, they referred to certain lutrine species previously reclassified to Enhydriodon as Sivaonyx, namely S. hendeyi and S.

It is generally thought that Enhydriodon was a result of a Miocene-Pleistocene trend that gave prehistoric lutrines bunodont teeth and large sizes compared to their extant relatives.

It is classified as a member of the bunodont otters group, a categorical term commonly used by researchers that also includes Sivaonyx, Paludolutra, Vishnuonyx, Torolutra, Enhydritherium, Djourabus, Paralutra, Tyrrhenolutra, Siamogale and Enhydra.

The researchers explained that the acquisition of bunodont dentition occurred at least three times in the evolution of lutrines, reflected by the phylogeny tree's clades: in Sivaonyx-Enhydriodon-Enhydra, in Paludolutra-Enhydritherium, and in Siamogale.

[10][15] The reclassification of all "African Sivaonyx" species other than S. beyi to Enhydriodon in 2022 has been attributed to "[a] metaconid higher than the protoconid on M1, presence of a carnassial notch and one or more cusps between the protocone and the hypocone on P4, and/or distolingual expansion on M1.

He also estimated the body of E. falconeri based on its lower M1 teeth dimensions to be similar to the African clawless otter (A. capensis), averaging to 16 kg (35 lb).

Pickford described E. kamuhangirei of the Western Rift Valley, Uganda (at the time Sivaonyx kamuhangirei) to possibly exceed 100 kg (220 lb) in weight, making it the largest-known prehistoric otter at the time, although he mentioned that the undescribed fossil otters in Ethiopia (likely sorted later under E. dikikae and/or E. omoensis) could have possibly been larger than it.

[14] As fossil bunodont otter genera including Enhydriodon generally lack complete specimens and postcranial elements, their locomotion and ecological niches remain uncertain.

However, the Omo and Hadar femoras' proximal ends pointed to a more aquatic nature than most lutrines, while their relative lengths resembled that of terrestrial generalist mustelids, including semiaquatic otters.

The standard deviation of Omo Enhydriodon aligns itself more within the range of extant terrestrial carnivorans such as hyaenids, suggesting that E. omoensis was not as semiaquatic as initially thought.

The large bunodont dentition of the species suggests durophageous abilities that allowed it to feed on carrion, including bones, in potentially a similar manner to hyeanas or bone-crushing mustelids.

[14] E. falconeri and E. sivalensis, while both Enhydriodon species that were present in the Siwalik Hills in India and Pakistan during the Neogene period, did not coexist for the same epochs based on their formation deposit appearances.

In the Nagri and Dhok Pathan Formations, E. falconeri was shown to have existed with several archaic mammalian carnivorous families that went extinct before the Pliocene, such as hyainailourine hyaenodonts and amphicyonids.

It is suggested that the extinction of the amphicyonids and percrocutids left empty predatory niches that were quickly filled by other hyaenid genera, which became highly diversified and coexisted with felids in the subcontinent.

[36][37][38] The carnivoran fossil records of the Tatrot Formation in India are scarce, but amongst the extinct members that existed with E. falconeri in the Pliocene were other lutrines, machairodontines, and hyaenids.

[28] Herbivorous mammals found at the Tatrot Formation on the Potwar Plateau contain highly diverse assemblages of bovids but also include cervids, suids, elephantids, stegodontids, hipparionines, anthracotheres, hippopotamids, giraffids, and tragulids.

However, the species identified within the Pinjor Formation of the Plio-Pleistocene epochs is E. sivalensis, which suggests that E. falconeri after a long time of relative success eventually might have gone through anagenesis by the Pliocene.

Other carnivoran genera that were found in the Pinjor Formation included the newly arrived canids as well as mustelids, ursids, felids (machairodontines, pantherines, and felines), hyaenids, and viverrids.

[28] Other mammalian genera found within the Pinjor Formation includes hominids, cercopithecids, rodents of various families, proboscideans, equines of the Equini tribe, rhinocerotids, suids, cervids, giraffids, and bovids.

The vegetation of SH-1 might have closely resembled those at the Guinea or Sudanese savannas that interdigitate with the central African rainforest, which creates habitat mosaics of grasslands, woodlands, and some forest belts.

The bovid tribes that were found in the formation included the Aepycerotini, Alcelaphini, Antilopini, Bovini, Caprini, Cephalophini, Hippotragini, Neotragini, Reduncini, and Tragelaphini.

There were a few exceptions, however, as Giraffidae and Deinotheriidae were both consistently C3 browsers within the formation while the bovid tribes Aepycerotini and Tragelaphini were predominantly mixed feeders with little change in diet.