Grandungulata

Grandungulata is a hypothetical extinct clade of herbivorous mammals that has been proposed to exist within the superorder Paenungulata. The name "Grandungulata" is derived from Latin words meaning "great ungulates." This group is hypothesized to have encompassed a diverse range of large, herbivorous mammals, though their exact phylogenetic placement and even their existence as a distinct group remain subjects of scientific debate.

The concept of Grandungulata emerged from attempts to classify and understand the evolutionary relationships of early ungulate-like mammals, particularly those with more generalized adaptations for herbivory. It was envisioned as a broad grouping that could potentially include or be closely related to groups such as the extinct Embrithopoda (e.g., Arsinoitherium), the sirenians (manatees and dugongs), the proboscideans (elephants), and the desmostylians. The idea was that these seemingly disparate groups might share a common, larger ancestral lineage exhibiting robust, herbivorous adaptations.

However, the validity and utility of Grandungulata as a formal taxonomic or phylogenetic unit are not widely accepted by paleontologists. Modern molecular and morphological studies have largely resolved the relationships between the extant paenungulate groups, placing them in distinct orders. While ancestral relationships are complex and subject to ongoing research, the broad concept of Grandungulata has been largely superseded by more refined phylogenetic analyses that favor a different arrangement of evolutionary lineages. Therefore, Grandungulata is best understood as a historical hypothesis rather than a currently recognized taxonomic group.