Eotungids

Eotungids are an extinct group of early mammaliforms known from fragmentary Paleogene fossils in Eurasia. The name, from Greek eos (dawn), reflects their status as early members of a northern Eurasian lineage linked by dental and cranial features reported in several studies. Because remains are fragmentary, the circumscription of Eotungidae as a natural group is debated.

Taxonomy and phylogeny: The placement of eotungids within Placentalia is uncertain. Some authors propose they are basal Euarchontoglires, others favor stem-Laurasiatheria, and several treat them as a paraphyletic assemblage of early insectivory-adapted mammals. Diagnoses rely largely on dental morphology, with limited postcranial material making robust phylogenetic tests difficult.

Morphology and ecology: Known remains indicate small to medium body size. Teeth are low-crowned and bunodont or sectorial, suggesting omnivorous or insectivorous diets. Limb bones imply a terrestrial to lightly cursorial lifestyle. Due to fragmentary evidence, ecological inferences remain tentative and vary among analyses.

Fossil record and distribution: Eotungid fossils have been reported mainly from East and Central Asia and parts of Europe, dating from the early to late Eocene in most accounts. The geographic and chronological range is debated, reflecting uncertainties in classification and the incompleteness of the fossil record.