Dromomeryx borealis

Overview

Dromomeryx borealis is a ruminant species encountered through North American fossils. Horns above and behind the eyes and its teeth provide clues to the animal. In older literature it also appears under the name Blastomeryx borealis.^[1][3]

Key facts

Two names do not necessarily mean two animals. The record of borealis must be read by connecting the old genus name Blastomeryx with the later Dromomeryx. Linking the names of old fossils is also part of completing the discovery story.^[3]

Time and place

Cope’s old description presented this fossil as an Upper Miocene occurrence from present-day Montana, USA. Later, its skull was also discussed in research on Miocene mammals from Beatty Buttes, Oregon. Following localities together with publications reveals the North American fossil record.^[1][2]

The time range describes source context, not the complete duration of this species.

Size, form and skeleton

The description places the horns above and behind the eye sockets. Horn cross-sections, crescent-shaped dental patterns, and a palate narrowing forward were also described. Projections on the skull and small features inside the mouth help distinguish the animal.^[1]

The estimated body mass is approximately 140 kg. Both fossil form and body-mass estimates provide a sense of this mammal’s size.^[4]

Habitat and reproduction

The Beatty Buttes material appears in a study treating several mammal fossils together. Dromomeryx skull and molar material can be found in that study. Moving beyond one species’ bones to read other fossil records from the locality provides a starting point for exploring its ancient setting.^[2]

Fossil discovery

The old description also preserves the discoverer’s name. Cope recorded that his assistant J. C. Isaac found the fossil in Montana. Connecting the name, locality, and discovery record lets us follow the field story behind the specimen.^[1]

References

1. Cope’s description — The skull, teeth and horns of borealis
2. Wallace (1946) — Dromomeryx skull from Beatty Buttes, Oregon
3. Morgan·Lucas (2023) — Linking the old and current names of borealis
4. Smits (2017), Remodeling the Fossil Record: Analysis of Emergent Evolutionary and Ecological Patterns
5. Study of Archaeomeryx morphology, ecology and artiodactyl evolution

Research questions

Even a compressed, distorted skull can be important evidence. CIT 3060, examined by Wallace, was substantially deformed but retained enough cheek teeth for comparison. Horn bases survived, and a separate molar specimen, CIT 3065, was also available. It illustrates how different fossils preserve different parts.^[2]

Observation

On the head, find where the horns begin above and behind the eyes. In fossil material, move your gaze to the crescent-like patterns on the teeth’s chewing surfaces. Alternating between the whole head outline and small dental patterns reveals different features.^[1]