Anulariphantus anulus: The Ring-Horned Proboscidean
While mammoths and mastodons characterize the popular view of Ice Age fauna, excavations in recent decades have uncovered evidence for far more obscure proboscideans roaming ancient Eurasia. Among these, Anulariphantus anulus represents one of the most fantastical - a massive elephant-like creature with thick circular horns adorning its head. Nicknamed the "Ring Ramphant," this exotic horned proboscidean persisted into the late Pleistocene between 120,000-40,000 years ago before vanishing from the fossil record.
First described scientifically in 2025, Anulariphantus belongs to the family Ariphantidae, considered an early divergence from elephantid stock around 7 million years ago. The genus name derives from "anulus," Latin for ring, combined with the elephant genus Loxodonta due to similarities in skull structure. However, the most striking features of Anulariphantus were the thick bony rings protruding from the frontal and rear portions of the cranium in both males and females.
These unique circular horns constituted the main anatomical distinction from ancestral elephantids. Composed of compact osteoderms like those found in armadillos, the frontal ring reached up to 120 cm diameter in old bulls. The rear cranial ring tended smaller at around 90 cm, with the two rings separated by an elevated bony ridge along the top of the skull. Isotopic studies show the horns were mineralized outward from a central core, adding a new layer each year like tree rings.
In contrast to other horned proboscideans, the rings of Anulariphantus lacked any spiraling or curvature. Their purpose also differed, as only males sported weaponized horns in other taxa. Instead, the circular rings likely served as battering rams for sparring contests over mates and social dominance. The thick keratin sheathing covering the outer horn added padding and protection to the skull during impacts. Anulariphantus fossils reveal abundant healed fractures radiating from the horn bases, evidence of frequent combat encounters.
Aside from its namesake horns, Anulariphantus generally resembled a typical elephant in body plan. Adults reached up to 4 meters at shoulder height and weighed 6 to 7 tons. Limb proportions were stocky like other cold-adapted proboscideans. Tusks grew up to 2.5 meters but pointed more directly downward compared to mammoth tusks. Coarse dark brown fur covered most of the body, with hypothesized mottled pink skin on the ears, face and trunk. Anulariphantus subsisted mainly on grasses and sedges across the mammoth steppe environment.
Starting around 300,000 years ago, Anulariphantus anulus evolved from the earlier species A. cyclus within Eurasia. This progenitor species lacked pronounced horn rings, instead exhibiting lower central knobs more akin to mammoth temporal lobes. Gradual changes in diet and climate favored selection for enlargement and elaboration of these bumps into full-fledged circular horns. The ring shape likely provided greater surface area for head impacts during mating disputes.
Anulariphantus populated the mammoth steppe biome, ranging vast distances to follow seasonal growth of vegetation. Isotopic studies indicate they favored semi-open habitats with elevated graminoid abundance, particularly in late summer. Many sites where their remains occur feature abundant yellowed grass pollen, suggesting a propensity for grasslands with mature seed heads. Herds migrated southward in winter, returning north to give birth when fresh greens sprouted.
While a bizarre marvel of proboscidean evolution, the Ring Ramphant ultimately faded into extinction around 40,000 years ago. Encroaching glaciers fragmented its habitat, while human hunting pressure mounted with the spread of stone tool cultures across Eurasia. Anulariphantus represents yet another evolutionary experiment cut short by climate shifts and expanding hominins near the close of the Pleistocene epoch. Though gone for millennia, picturing its improbable ring-horned silhouette lets us envision lost Pleistocene diversity.