Euprimates are the earliest true primates, appearing in the fossil record during the Eocene epoch (~56–34 million years ago). They represent the first fully recognizable members of the primate order, distinguished from more primitive primate-like mammals (plesiadapiforms).

🌍 Definition

• Euprimates: The “true primates,” an extinct group that includes the earliest ancestors of modern primates.
• Name origin: eu- (“true”) + primates (“first rank”).
• They mark the evolutionary transition toward the primate traits we see today in monkeys, apes, and humans.

🔑 Characteristics

• Grasping Hands & Feet: With nails instead of claws, adapted for arboreal life.
• Forward-Facing Eyes: Enhanced stereoscopic vision for depth perception.
• Postorbital Bar: Bony structure around the eye socket, protecting vision.
• Small Body Size: Most were squirrel-sized.
• Diet: Likely frugivorous or insectivorous.

📚 Major Groups

• Adapiforms: Lemur-like primates, diurnal, mostly frugivorous.
• Omomyiforms: Tarsier-like primates, nocturnal, insectivorous.
• Both groups show diversification across North America, Europe, Asia, and Africa during the Eocene.

🛠 Evolutionary Significance

• First Radiation of Primates: Euprimates represent the initial adaptive radiation of primates into ecological niches.
• Link to Modern Primates: Adapiforms are often considered related to strepsirrhines (lemurs, lorises), while omomyiforms are linked to haplorhines (tarsiers, monkeys, apes).
• Paleoclimate Context: Their emergence coincides with the Eocene Thermal Maximum, a period of global warming that expanded tropical forests and created habitats for arboreal primates.

✨ Summary

Euprimates are the earliest true primates, appearing in the Eocene with grasping hands, forward-facing eyes, and arboreal adaptations. They split into two major groups—adapiforms and omomyiforms—that foreshadow the later divergence of lemurs, monkeys, and apes.